[support.limits]

# 17 Language support library [[support]](./#support)

## 17.3 Implementation properties [support.limits]

### [17.3.1](#general) General [[support.limits.general]](support.limits.general)

[1](#general-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L527)

The headers[<limits>](#header:%3climits%3e "17.3.3 Header <limits> synopsis [limits.syn]"),[<climits>](#header:%3cclimits%3e "17.3.6 Header <climits> synopsis [climits.syn]"), and[<cfloat>](#header:%3ccfloat%3e "17.3.7 Header <cfloat> synopsis [cfloat.syn]") supply characteristics ofimplementation-dependent
arithmetic types ([[basic.fundamental]](basic.fundamental "6.9.2 Fundamental types"))[.](#general-1.sentence-1)

### [17.3.2](#version.syn) Header <version> synopsis [[version.syn]](version.syn)

[1](#version.syn-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L539)

The header <version> supplies implementation-dependent information
about the C++ standard library
(e.g., version number and release date)[.](#version.syn-1.sentence-1)

[2](#version.syn-2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L545)

Each of the macros defined in [<version>](#header:%3cversion%3e "17.3.2 Header <version> synopsis [version.syn]") is also defined
after inclusion of any member of the set of library headers
indicated in the corresponding comment in this synopsis[.](#version.syn-2.sentence-1)

[*Note [1](#version.syn-note-1)*:

Future revisions of this document might replace
the values of these macros with greater values[.](#version.syn-2.sentence-2)

— *end note*]

#define __cpp_lib_adaptor_iterator_pair_constructor 202106L // also in [<stack>](stack.syn#header:%3cstack%3e "23.6.5 Header <stack> synopsis [stack.syn]"), [<queue>](queue.syn#header:%3cqueue%3e "23.6.2 Header <queue> synopsis [queue.syn]")#define __cpp_lib_addressof_constexpr 201603L // freestanding, also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_algorithm_default_value_type 202403L// also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]"), [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]"), [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]"), [<deque>](deque.syn#header:%3cdeque%3e "23.3.4 Header <deque> synopsis [deque.syn]"), [<list>](list.syn#header:%3clist%3e "23.3.10 Header <list> synopsis [list.syn]"), [<forward_list>](forward.list.syn#header:%3cforward_list%3e "23.3.6 Header <forward_­list> synopsis [forward.list.syn]"), [<vector>](vector.syn#header:%3cvector%3e "23.3.12 Header <vector> synopsis [vector.syn]")#define __cpp_lib_algorithm_iterator_requirements 202207L// also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]"), [<numeric>](numeric.ops.overview#header:%3cnumeric%3e "26.9 Header <numeric> synopsis [numeric.ops.overview]"), [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_aligned_accessor 202411L // also in [<mdspan>](mdspan.syn#header:%3cmdspan%3e "23.7.3.2 Header <mdspan> synopsis [mdspan.syn]")#define __cpp_lib_allocate_at_least 202302L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_allocator_traits_is_always_equal 201411L// freestanding, also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]"), [<scoped_allocator>](allocator.adaptor.syn#header:%3cscoped_allocator%3e "20.6.1 Header <scoped_­allocator> synopsis [allocator.adaptor.syn]"), [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]"), [<deque>](deque.syn#header:%3cdeque%3e "23.3.4 Header <deque> synopsis [deque.syn]"), [<forward_list>](forward.list.syn#header:%3cforward_list%3e "23.3.6 Header <forward_­list> synopsis [forward.list.syn]"), [<list>](list.syn#header:%3clist%3e "23.3.10 Header <list> synopsis [list.syn]"),// [<vector>](vector.syn#header:%3cvector%3e "23.3.12 Header <vector> synopsis [vector.syn]"), [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]"), [<set>](associative.set.syn#header:%3cset%3e "23.4.5 Header <set> synopsis [associative.set.syn]"), [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]"), [<unordered_set>](unord.set.syn#header:%3cunordered_set%3e "23.5.5 Header <unordered_­set> synopsis [unord.set.syn]")#define __cpp_lib_any 201606L // also in [<any>](any.synop#header:%3cany%3e "22.7.2 Header <any> synopsis [any.synop]")#define __cpp_lib_apply 202506L // freestanding, also in [<tuple>](tuple.syn#header:%3ctuple%3e "22.4.2 Header <tuple> synopsis [tuple.syn]"), [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_array_constexpr 201811L // also in [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]"), [<array>](array.syn#header:%3carray%3e "23.3.2 Header <array> synopsis [array.syn]")#define __cpp_lib_as_const 201510L // freestanding, also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_associative_heterogeneous_erasure 202110L// also in [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]"), [<set>](associative.set.syn#header:%3cset%3e "23.4.5 Header <set> synopsis [associative.set.syn]"), [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]"), [<unordered_set>](unord.set.syn#header:%3cunordered_set%3e "23.5.5 Header <unordered_­set> synopsis [unord.set.syn]")#define __cpp_lib_associative_heterogeneous_insertion 202306L// also in [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]"), [<set>](associative.set.syn#header:%3cset%3e "23.4.5 Header <set> synopsis [associative.set.syn]"), [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]"), [<unordered_set>](unord.set.syn#header:%3cunordered_set%3e "23.5.5 Header <unordered_­set> synopsis [unord.set.syn]")#define __cpp_lib_assume_aligned 201811L // freestanding, also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_atomic_flag_test 201907L // freestanding, also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]")#define __cpp_lib_atomic_float 201711L // freestanding, also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]")#define __cpp_lib_atomic_is_always_lock_free 201603L // freestanding, also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]")#define __cpp_lib_atomic_lock_free_type_aliases 201907L // also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]")#define __cpp_lib_atomic_min_max 202506L // freestanding, also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]")#define __cpp_lib_atomic_reductions 202506L // freestanding, also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]")#define __cpp_lib_atomic_ref 202411L // freestanding, also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]")#define __cpp_lib_atomic_shared_ptr 201711L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_atomic_value_initialization 201911L // freestanding, also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]"), [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_atomic_wait 201907L // freestanding, also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]")#define __cpp_lib_barrier 202302L // also in [<barrier>](barrier.syn#header:%3cbarrier%3e "32.9.3.2 Header <barrier> synopsis [barrier.syn]")#define __cpp_lib_bind_back 202306L // freestanding, also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_bind_front 202306L // freestanding, also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_bit_cast 201806L // freestanding, also in [<bit>](bit.general#header:%3cbit%3e "22.11.1 General [bit.general]")#define __cpp_lib_bitops 201907L // freestanding, also in [<bit>](bit.general#header:%3cbit%3e "22.11.1 General [bit.general]")#define __cpp_lib_bitset 202306L // also in [<bitset>](bitset.syn#header:%3cbitset%3e "22.9.1 Header <bitset> synopsis [bitset.syn]")#define __cpp_lib_bool_constant 201505L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_bounded_array_traits 201902L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_boyer_moore_searcher 201603L // also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_byte 201603L // freestanding, also in [<cstddef>](cstddef.syn#header:%3ccstddef%3e "17.2.1 Header <cstddef> synopsis [cstddef.syn]")#define __cpp_lib_byteswap 202110L // freestanding, also in [<bit>](bit.general#header:%3cbit%3e "22.11.1 General [bit.general]")#define __cpp_lib_char8_t 201907L// freestanding, also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]"), [<filesystem>](fs.filesystem.syn#header:%3cfilesystem%3e "31.12.4 Header <filesystem> synopsis [fs.filesystem.syn]"), [<istream>](istream.syn#header:%3cistream%3e "31.7.1 Header <istream> synopsis [istream.syn]"), [<limits>](#header:%3climits%3e "17.3.3 Header <limits> synopsis [limits.syn]"), [<locale>](locale.syn#header:%3clocale%3e "28.3.2 Header <locale> synopsis [locale.syn]"), [<ostream>](ostream.syn#header:%3costream%3e "31.7.2 Header <ostream> synopsis [ostream.syn]"), [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]"),// [<string_view>](string.view.synop#header:%3cstring_view%3e "27.3.2 Header <string_­view> synopsis [string.view.synop]")#define __cpp_lib_chrono 202306L // also in [<chrono>](time.syn#header:%3cchrono%3e "30.2 Header <chrono> synopsis [time.syn]")#define __cpp_lib_chrono_udls 201304L // also in [<chrono>](time.syn#header:%3cchrono%3e "30.2 Header <chrono> synopsis [time.syn]")#define __cpp_lib_clamp 201603L // also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]")#define __cpp_lib_common_reference 202302L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_common_reference_wrapper 202302L // freestanding, also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_complex_udls 201309L // also in [<complex>](complex.syn#header:%3ccomplex%3e "29.4.2 Header <complex> synopsis [complex.syn]")#define __cpp_lib_concepts 202207L// freestanding, also in [<concepts>](concepts.syn#header:%3cconcepts%3e "18.3 Header <concepts> synopsis [concepts.syn]"), [<compare>](compare.syn#header:%3ccompare%3e "17.12.1 Header <compare> synopsis [compare.syn]")#define __cpp_lib_constant_wrapper 202506L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_constexpr_algorithms 202306L // also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]"), [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_constexpr_atomic 202411L // also in [<atomic>](atomics.syn#header:%3catomic%3e "32.5.2 Header <atomic> synopsis [atomics.syn]")#define __cpp_lib_constexpr_bitset 202207L // also in [<bitset>](bitset.syn#header:%3cbitset%3e "22.9.1 Header <bitset> synopsis [bitset.syn]")#define __cpp_lib_constexpr_charconv 202207L // freestanding, also in [<charconv>](charconv.syn#header:%3ccharconv%3e "28.2.1 Header <charconv> synopsis [charconv.syn]")#define __cpp_lib_constexpr_cmath 202306L // also in [<cmath>](cmath.syn#header:%3ccmath%3e "29.7.1 Header <cmath> synopsis [cmath.syn]"), [<cstdlib>](cstdlib.syn#header:%3ccstdlib%3e "17.2.2 Header <cstdlib> synopsis [cstdlib.syn]")#define __cpp_lib_constexpr_complex 202306L // also in [<complex>](complex.syn#header:%3ccomplex%3e "29.4.2 Header <complex> synopsis [complex.syn]")#define __cpp_lib_constexpr_deque 202502L // also in [<deque>](deque.syn#header:%3cdeque%3e "23.3.4 Header <deque> synopsis [deque.syn]")#define __cpp_lib_constexpr_dynamic_alloc 201907L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_constexpr_exceptions 202502L// also in [<exception>](support.exception.general#header:%3cexception%3e "17.9.1 General [support.exception.general]"), [<stdexcept>](std.exceptions.general#header:%3cstdexcept%3e "19.2.1 General [std.exceptions.general]"), [<expected>](expected.syn#header:%3cexpected%3e "22.8.2 Header <expected> synopsis [expected.syn]"), [<optional>](optional.syn#header:%3coptional%3e "22.5.2 Header <optional> synopsis [optional.syn]"), [<variant>](variant.syn#header:%3cvariant%3e "22.6.2 Header <variant> synopsis [variant.syn]"), and [<format>](format.formatter.spec#header:%3cformat%3e "28.5.6.4 Formatter specializations [format.formatter.spec]")#define __cpp_lib_constexpr_flat_map 202502L // also in [<flat_map>](flat.map.syn#header:%3cflat_map%3e "23.6.7 Header <flat_­map> synopsis [flat.map.syn]")#define __cpp_lib_constexpr_flat_set 202502L // also in [<flat_set>](flat.set.syn#header:%3cflat_set%3e "23.6.10 Header <flat_­set> synopsis [flat.set.syn]")#define __cpp_lib_constexpr_forward_list 202502L // also in [<forward_list>](forward.list.syn#header:%3cforward_list%3e "23.3.6 Header <forward_­list> synopsis [forward.list.syn]")#define __cpp_lib_constexpr_functional 201907L // freestanding, also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_constexpr_inplace_vector 202502L // also in [<inplace_vector>](inplace.vector.syn#header:%3cinplace_vector%3e "23.3.15 Header <inplace_­vector> synopsis [inplace.vector.syn]")#define __cpp_lib_constexpr_iterator 201811L // freestanding, also in [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]")#define __cpp_lib_constexpr_list 202502L // also in [<list>](list.syn#header:%3clist%3e "23.3.10 Header <list> synopsis [list.syn]")#define __cpp_lib_constexpr_map 202502L // also in [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]")#define __cpp_lib_constexpr_memory 202506L // freestanding, also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_constexpr_new 202406L // freestanding, also in [<new>](support.dynamic.general#header:%3cnew%3e "17.6.1 General [support.dynamic.general]")#define __cpp_lib_constexpr_numeric 201911L // also in [<numeric>](numeric.ops.overview#header:%3cnumeric%3e "26.9 Header <numeric> synopsis [numeric.ops.overview]")#define __cpp_lib_constexpr_queue 202502L // also in [<queue>](queue.syn#header:%3cqueue%3e "23.6.2 Header <queue> synopsis [queue.syn]")#define __cpp_lib_constexpr_set 202502L // also in [<set>](associative.set.syn#header:%3cset%3e "23.4.5 Header <set> synopsis [associative.set.syn]")#define __cpp_lib_constexpr_stack 202502L // also in [<stack>](stack.syn#header:%3cstack%3e "23.6.5 Header <stack> synopsis [stack.syn]")#define __cpp_lib_constexpr_string 201907L // also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]")#define __cpp_lib_constexpr_string_view 201811L // also in [<string_view>](string.view.synop#header:%3cstring_view%3e "27.3.2 Header <string_­view> synopsis [string.view.synop]")#define __cpp_lib_constexpr_tuple 201811L // freestanding, also in [<tuple>](tuple.syn#header:%3ctuple%3e "22.4.2 Header <tuple> synopsis [tuple.syn]")#define __cpp_lib_constexpr_typeinfo 202106L // freestanding, also in [<typeinfo>](typeinfo.syn#header:%3ctypeinfo%3e "17.7.2 Header <typeinfo> synopsis [typeinfo.syn]")#define __cpp_lib_constexpr_unordered_map 202502L // also in [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]")#define __cpp_lib_constexpr_unordered_set 202502L // also in [<unordered_set>](unord.set.syn#header:%3cunordered_set%3e "23.5.5 Header <unordered_­set> synopsis [unord.set.syn]")#define __cpp_lib_constexpr_utility 201811L // freestanding, also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_constexpr_vector 201907L // also in [<vector>](vector.syn#header:%3cvector%3e "23.3.12 Header <vector> synopsis [vector.syn]")#define __cpp_lib_constrained_equality 202411L // freestanding,// also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]"), [<tuple>](tuple.syn#header:%3ctuple%3e "22.4.2 Header <tuple> synopsis [tuple.syn]"), [<optional>](optional.syn#header:%3coptional%3e "22.5.2 Header <optional> synopsis [optional.syn]"), [<variant>](variant.syn#header:%3cvariant%3e "22.6.2 Header <variant> synopsis [variant.syn]"), [<expected>](expected.syn#header:%3cexpected%3e "22.8.2 Header <expected> synopsis [expected.syn]")#define __cpp_lib_containers_ranges 202202L// also in [<vector>](vector.syn#header:%3cvector%3e "23.3.12 Header <vector> synopsis [vector.syn]"), [<list>](list.syn#header:%3clist%3e "23.3.10 Header <list> synopsis [list.syn]"), [<forward_list>](forward.list.syn#header:%3cforward_list%3e "23.3.6 Header <forward_­list> synopsis [forward.list.syn]"), [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]"), [<set>](associative.set.syn#header:%3cset%3e "23.4.5 Header <set> synopsis [associative.set.syn]"), [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]"), [<unordered_set>](unord.set.syn#header:%3cunordered_set%3e "23.5.5 Header <unordered_­set> synopsis [unord.set.syn]"),// [<deque>](deque.syn#header:%3cdeque%3e "23.3.4 Header <deque> synopsis [deque.syn]"), [<queue>](queue.syn#header:%3cqueue%3e "23.6.2 Header <queue> synopsis [queue.syn]"), [<stack>](stack.syn#header:%3cstack%3e "23.6.5 Header <stack> synopsis [stack.syn]"), [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]")#define __cpp_lib_contracts 202502L // freestanding, also in [<contracts>](contracts.syn#header:%3ccontracts%3e "17.10.1 Header <contracts> synopsis [contracts.syn]")#define __cpp_lib_copyable_function 202306L // also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_coroutine 201902L // freestanding, also in [<coroutine>](coroutine.syn#header:%3ccoroutine%3e "17.13.2 Header <coroutine> synopsis [coroutine.syn]")#define __cpp_lib_counting_scope 202506L // also in [<execution>](execution.syn#header:%3cexecution%3e "33.4 Header <execution> synopsis [execution.syn]")#define __cpp_lib_debugging 202403L // freestanding, also in [<debugging>](debugging.syn#header:%3cdebugging%3e "19.7.2 Header <debugging> synopsis [debugging.syn]")#define __cpp_lib_define_static 202506L // freestanding, also in [<meta>](meta.syn#header:%3cmeta%3e "21.4.1 Header <meta> synopsis [meta.syn]")#define __cpp_lib_destroying_delete 201806L // freestanding, also in [<new>](support.dynamic.general#header:%3cnew%3e "17.6.1 General [support.dynamic.general]")#define __cpp_lib_enable_shared_from_this 201603L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_endian 201907L // freestanding, also in [<bit>](bit.general#header:%3cbit%3e "22.11.1 General [bit.general]")#define __cpp_lib_erase_if 202002L// also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]"), [<deque>](deque.syn#header:%3cdeque%3e "23.3.4 Header <deque> synopsis [deque.syn]"), [<forward_list>](forward.list.syn#header:%3cforward_list%3e "23.3.6 Header <forward_­list> synopsis [forward.list.syn]"), [<list>](list.syn#header:%3clist%3e "23.3.10 Header <list> synopsis [list.syn]"), [<vector>](vector.syn#header:%3cvector%3e "23.3.12 Header <vector> synopsis [vector.syn]"), [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]"), [<set>](associative.set.syn#header:%3cset%3e "23.4.5 Header <set> synopsis [associative.set.syn]"), [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]"),// [<unordered_set>](unord.set.syn#header:%3cunordered_set%3e "23.5.5 Header <unordered_­set> synopsis [unord.set.syn]")#define __cpp_lib_exception_ptr_cast 202506L // also in [<exception>](support.exception.general#header:%3cexception%3e "17.9.1 General [support.exception.general]")#define __cpp_lib_exchange_function 201304L // freestanding, also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_execution 201902L // also in [<execution>](execution.syn#header:%3cexecution%3e "33.4 Header <execution> synopsis [execution.syn]")#define __cpp_lib_expected 202211L // also in [<expected>](expected.syn#header:%3cexpected%3e "22.8.2 Header <expected> synopsis [expected.syn]")#define __cpp_lib_filesystem 201703L // also in [<filesystem>](fs.filesystem.syn#header:%3cfilesystem%3e "31.12.4 Header <filesystem> synopsis [fs.filesystem.syn]")#define __cpp_lib_flat_map 202207L // also in [<flat_map>](flat.map.syn#header:%3cflat_map%3e "23.6.7 Header <flat_­map> synopsis [flat.map.syn]")#define __cpp_lib_flat_set 202207L // also in [<flat_set>](flat.set.syn#header:%3cflat_set%3e "23.6.10 Header <flat_­set> synopsis [flat.set.syn]")#define __cpp_lib_format 202311L // also in [<format>](format.formatter.spec#header:%3cformat%3e "28.5.6.4 Formatter specializations [format.formatter.spec]")#define __cpp_lib_format_ranges 202207L // also in [<format>](format.formatter.spec#header:%3cformat%3e "28.5.6.4 Formatter specializations [format.formatter.spec]")#define __cpp_lib_format_path 202506L // also in [<filesystem>](fs.filesystem.syn#header:%3cfilesystem%3e "31.12.4 Header <filesystem> synopsis [fs.filesystem.syn]")#define __cpp_lib_format_uchar 202311L // also in [<format>](format.formatter.spec#header:%3cformat%3e "28.5.6.4 Formatter specializations [format.formatter.spec]")#define __cpp_lib_formatters 202302L // also in [<stacktrace>](stacktrace.syn#header:%3cstacktrace%3e "19.6.2 Header <stacktrace> synopsis [stacktrace.syn]"), [<thread>](thread.syn#header:%3cthread%3e "32.4.2 Header <thread> synopsis [thread.syn]")#define __cpp_lib_forward_like 202207L // freestanding, also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_freestanding_algorithm 202502L // freestanding, also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]")#define __cpp_lib_freestanding_array 202311L // freestanding, also in [<array>](array.syn#header:%3carray%3e "23.3.2 Header <array> synopsis [array.syn]")#define __cpp_lib_freestanding_char_traits 202306L // freestanding, also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]")#define __cpp_lib_freestanding_charconv 202306L // freestanding, also in [<charconv>](charconv.syn#header:%3ccharconv%3e "28.2.1 Header <charconv> synopsis [charconv.syn]")#define __cpp_lib_freestanding_cstdlib 202306L // freestanding, also in [<cstdlib>](cstdlib.syn#header:%3ccstdlib%3e "17.2.2 Header <cstdlib> synopsis [cstdlib.syn]"), [<cmath>](cmath.syn#header:%3ccmath%3e "29.7.1 Header <cmath> synopsis [cmath.syn]")#define __cpp_lib_freestanding_cstring 202311L // freestanding, also in [<cstring>](cstring.syn#header:%3ccstring%3e "27.5.1 Header <cstring> synopsis [cstring.syn]")#define __cpp_lib_freestanding_cwchar 202306L // freestanding, also in [<cwchar>](cwchar.syn#header:%3ccwchar%3e "28.7.3 Header <cwchar> synopsis [cwchar.syn]")#define __cpp_lib_freestanding_errc 202306L// freestanding, also in [<cerrno>](errno.general#header:%3ccerrno%3e "19.4.1 General [errno.general]"), [<system_error>](system.error.syn#header:%3csystem_error%3e "19.5.2 Header <system_­error> synopsis [system.error.syn]")#define __cpp_lib_freestanding_execution 202502L // freestanding, also in [<execution>](execution.syn#header:%3cexecution%3e "33.4 Header <execution> synopsis [execution.syn]")#define __cpp_lib_freestanding_expected 202311L // freestanding, also in [<expected>](expected.syn#header:%3cexpected%3e "22.8.2 Header <expected> synopsis [expected.syn]")#define __cpp_lib_freestanding_feature_test_macros 202306L // freestanding#define __cpp_lib_freestanding_functional 202306L // freestanding, also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_freestanding_iterator 202306L // freestanding, also in [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]")#define __cpp_lib_freestanding_mdspan 202311L // freestanding, also in [<mdspan>](mdspan.syn#header:%3cmdspan%3e "23.7.3.2 Header <mdspan> synopsis [mdspan.syn]")#define __cpp_lib_freestanding_memory 202502L // freestanding, also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_freestanding_numeric 202502L // freestanding, also in [<numeric>](numeric.ops.overview#header:%3cnumeric%3e "26.9 Header <numeric> synopsis [numeric.ops.overview]")#define __cpp_lib_freestanding_operator_new *see below* // freestanding, also in [<new>](support.dynamic.general#header:%3cnew%3e "17.6.1 General [support.dynamic.general]")#define __cpp_lib_freestanding_optional 202506L // freestanding, also in [<optional>](optional.syn#header:%3coptional%3e "22.5.2 Header <optional> synopsis [optional.syn]")#define __cpp_lib_freestanding_random 202502L // freestanding, also in [<random>](rand.synopsis#header:%3crandom%3e "29.5.2 Header <random> synopsis [rand.synopsis]")#define __cpp_lib_freestanding_ranges 202306L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_freestanding_ratio 202306L // freestanding, also in [<ratio>](ratio.syn#header:%3cratio%3e "21.5.2 Header <ratio> synopsis [ratio.syn]")#define __cpp_lib_freestanding_string_view 202311L // freestanding, also in [<string_view>](string.view.synop#header:%3cstring_view%3e "27.3.2 Header <string_­view> synopsis [string.view.synop]")#define __cpp_lib_freestanding_tuple 202306L // freestanding, also in [<tuple>](tuple.syn#header:%3ctuple%3e "22.4.2 Header <tuple> synopsis [tuple.syn]")#define __cpp_lib_freestanding_utility 202306L // freestanding, also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_freestanding_variant 202311L // freestanding, also in [<variant>](variant.syn#header:%3cvariant%3e "22.6.2 Header <variant> synopsis [variant.syn]")#define __cpp_lib_fstream_native_handle 202306L // also in [<fstream>](fstream.syn#header:%3cfstream%3e "31.10.1 Header <fstream> synopsis [fstream.syn]")#define __cpp_lib_function_ref 202306L // also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_gcd_lcm 201606L // also in [<numeric>](numeric.ops.overview#header:%3cnumeric%3e "26.9 Header <numeric> synopsis [numeric.ops.overview]")#define __cpp_lib_generator 202207L // also in [<generator>](generator.syn#header:%3cgenerator%3e "25.8.2 Header <generator> synopsis [generator.syn]")#define __cpp_lib_generic_associative_lookup 201304L // also in [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]"), [<set>](associative.set.syn#header:%3cset%3e "23.4.5 Header <set> synopsis [associative.set.syn]")#define __cpp_lib_generic_unordered_lookup 201811L// also in [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]"), [<unordered_set>](unord.set.syn#header:%3cunordered_set%3e "23.5.5 Header <unordered_­set> synopsis [unord.set.syn]")#define __cpp_lib_hardware_interference_size 201703L // freestanding, also in [<new>](support.dynamic.general#header:%3cnew%3e "17.6.1 General [support.dynamic.general]")#define __cpp_lib_has_unique_object_representations 201606L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_hazard_pointer 202306L // also in [<hazard_pointer>](hazard.pointer.syn#header:%3chazard_pointer%3e "32.11.3.2 Header <hazard_­pointer> synopsis [hazard.pointer.syn]")#define __cpp_lib_hive 202502L // also in [<hive>](hive.syn#header:%3chive%3e "23.3.8 Header <hive> synopsis [hive.syn]")#define __cpp_lib_hypot 201603L // also in [<cmath>](cmath.syn#header:%3ccmath%3e "29.7.1 Header <cmath> synopsis [cmath.syn]")#define __cpp_lib_incomplete_container_elements 201505L// also in [<forward_list>](forward.list.syn#header:%3cforward_list%3e "23.3.6 Header <forward_­list> synopsis [forward.list.syn]"), [<list>](list.syn#header:%3clist%3e "23.3.10 Header <list> synopsis [list.syn]"), [<vector>](vector.syn#header:%3cvector%3e "23.3.12 Header <vector> synopsis [vector.syn]")#define __cpp_lib_indirect 202502L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_inplace_vector 202406L // also in [<inplace_vector>](inplace.vector.syn#header:%3cinplace_vector%3e "23.3.15 Header <inplace_­vector> synopsis [inplace.vector.syn]")#define __cpp_lib_int_pow2 202002L // freestanding, also in [<bit>](bit.general#header:%3cbit%3e "22.11.1 General [bit.general]")#define __cpp_lib_integer_comparison_functions 202002L // also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_integer_sequence 201304L // freestanding, also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_integral_constant_callable 201304L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_interpolate 201902L // also in [<cmath>](cmath.syn#header:%3ccmath%3e "29.7.1 Header <cmath> synopsis [cmath.syn]"), [<numeric>](numeric.ops.overview#header:%3cnumeric%3e "26.9 Header <numeric> synopsis [numeric.ops.overview]")#define __cpp_lib_invoke 201411L // freestanding, also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_invoke_r 202106L // freestanding, also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_ios_noreplace 202207L // also in [<ios>](ios.syn#header:%3cios%3e "31.5.1 Header <ios> synopsis [ios.syn]")#define __cpp_lib_is_aggregate 201703L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_constant_evaluated 201811L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_final 201402L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_implicit_lifetime 202302L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_invocable 201703L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_layout_compatible 201907L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_nothrow_convertible 201806L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_null_pointer 201309L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_pointer_interconvertible 201907L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_scoped_enum 202011L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_sufficiently_aligned 202411L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_is_swappable 201603L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_virtual_base_of 202406L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_is_within_lifetime 202306L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_jthread 201911L // also in [<stop_token>](thread.stoptoken.syn#header:%3cstop_token%3e "32.3.2 Header <stop_­token> synopsis [thread.stoptoken.syn]"), [<thread>](thread.syn#header:%3cthread%3e "32.4.2 Header <thread> synopsis [thread.syn]")#define __cpp_lib_latch 201907L // also in [<latch>](latch.syn#header:%3clatch%3e "32.9.2.2 Header <latch> synopsis [latch.syn]")#define __cpp_lib_launder 201606L // freestanding, also in [<new>](support.dynamic.general#header:%3cnew%3e "17.6.1 General [support.dynamic.general]")#define __cpp_lib_linalg 202412L // also in [<linalg>](linalg.syn#header:%3clinalg%3e "29.9.2 Header <linalg> synopsis [linalg.syn]")#define __cpp_lib_list_remove_return_type 201806L // also in [<forward_list>](forward.list.syn#header:%3cforward_list%3e "23.3.6 Header <forward_­list> synopsis [forward.list.syn]"), [<list>](list.syn#header:%3clist%3e "23.3.10 Header <list> synopsis [list.syn]")#define __cpp_lib_logical_traits 201510L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_make_from_tuple 201606L // freestanding, also in [<tuple>](tuple.syn#header:%3ctuple%3e "22.4.2 Header <tuple> synopsis [tuple.syn]")#define __cpp_lib_make_reverse_iterator 201402L // freestanding, also in [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]")#define __cpp_lib_make_unique 201304L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_map_try_emplace 201411L // also in [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]")#define __cpp_lib_math_constants 201907L // also in [<numbers>](numbers.syn#header:%3cnumbers%3e "29.8.1 Header <numbers> synopsis [numbers.syn]")#define __cpp_lib_math_special_functions 201603L // also in [<cmath>](cmath.syn#header:%3ccmath%3e "29.7.1 Header <cmath> synopsis [cmath.syn]")#define __cpp_lib_mdspan 202406L // freestanding, also in [<mdspan>](mdspan.syn#header:%3cmdspan%3e "23.7.3.2 Header <mdspan> synopsis [mdspan.syn]")#define __cpp_lib_memory_resource 201603L // also in [<memory_resource>](mem.res.syn#header:%3cmemory_resource%3e "20.5.1 Header <memory_­resource> synopsis [mem.res.syn]")#define __cpp_lib_modules 202207L // freestanding#define __cpp_lib_move_iterator_concept 202207L // freestanding, also in [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]")#define __cpp_lib_move_only_function 202110L // also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_node_extract 201606L// also in [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]"), [<set>](associative.set.syn#header:%3cset%3e "23.4.5 Header <set> synopsis [associative.set.syn]"), [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]"), [<unordered_set>](unord.set.syn#header:%3cunordered_set%3e "23.5.5 Header <unordered_­set> synopsis [unord.set.syn]")#define __cpp_lib_nonmember_container_access 201411L// freestanding, also in [<array>](array.syn#header:%3carray%3e "23.3.2 Header <array> synopsis [array.syn]"), [<deque>](deque.syn#header:%3cdeque%3e "23.3.4 Header <deque> synopsis [deque.syn]"), [<forward_list>](forward.list.syn#header:%3cforward_list%3e "23.3.6 Header <forward_­list> synopsis [forward.list.syn]"), [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]"), [<list>](list.syn#header:%3clist%3e "23.3.10 Header <list> synopsis [list.syn]"), [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]"), [<regex>](re.syn#header:%3cregex%3e "28.6.3 Header <regex> synopsis [re.syn]"), [<set>](associative.set.syn#header:%3cset%3e "23.4.5 Header <set> synopsis [associative.set.syn]"),// [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]"), [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]"), [<unordered_set>](unord.set.syn#header:%3cunordered_set%3e "23.5.5 Header <unordered_­set> synopsis [unord.set.syn]"), [<vector>](vector.syn#header:%3cvector%3e "23.3.12 Header <vector> synopsis [vector.syn]")#define __cpp_lib_not_fn 202306L // freestanding, also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_null_iterators 201304L // freestanding, also in [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]")#define __cpp_lib_observable_checkpoint 202506L // freestanding, also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_optional 202506L // also in [<optional>](optional.syn#header:%3coptional%3e "22.5.2 Header <optional> synopsis [optional.syn]")#define __cpp_lib_optional_range_support 202406L // freestanding, also in [<optional>](optional.syn#header:%3coptional%3e "22.5.2 Header <optional> synopsis [optional.syn]")#define __cpp_lib_out_ptr 202311L // freestanding, also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_parallel_algorithm 202506L// also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]"), [<numeric>](numeric.ops.overview#header:%3cnumeric%3e "26.9 Header <numeric> synopsis [numeric.ops.overview]"), [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_parallel_scheduler 202506L // also in [<execution>](execution.syn#header:%3cexecution%3e "33.4 Header <execution> synopsis [execution.syn]")#define __cpp_lib_philox_engine 202406L // also in [<random>](rand.synopsis#header:%3crandom%3e "29.5.2 Header <random> synopsis [rand.synopsis]")#define __cpp_lib_polymorphic 202502L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_polymorphic_allocator 201902L // also in [<memory_resource>](mem.res.syn#header:%3cmemory_resource%3e "20.5.1 Header <memory_­resource> synopsis [mem.res.syn]")#define __cpp_lib_print 202406L // also in [<print>](print.syn#header:%3cprint%3e "31.7.4 Header <print> synopsis [print.syn]"), [<ostream>](ostream.syn#header:%3costream%3e "31.7.2 Header <ostream> synopsis [ostream.syn]")#define __cpp_lib_quoted_string_io 201304L // also in [<iomanip>](iomanip.syn#header:%3ciomanip%3e "31.7.3 Header <iomanip> synopsis [iomanip.syn]")#define __cpp_lib_ranges 202406L// also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]"), [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]"), [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]"), [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]"), [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_as_const 202311L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_as_rvalue 202207L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_cache_latest 202411L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_cartesian_product 202207L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_chunk 202202L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_chunk_by 202202L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_concat 202403L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_contains 202207L // also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]")#define __cpp_lib_ranges_enumerate 202302L // also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_find_last 202207L // also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]")#define __cpp_lib_ranges_fold 202207L // also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]")#define __cpp_lib_ranges_generate_random 202403L // also in [<random>](rand.synopsis#header:%3crandom%3e "29.5.2 Header <random> synopsis [rand.synopsis]")#define __cpp_lib_ranges_indices 202506L // also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_iota 202202L // also in [<numeric>](numeric.ops.overview#header:%3cnumeric%3e "26.9 Header <numeric> synopsis [numeric.ops.overview]")#define __cpp_lib_ranges_join_with 202202L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_repeat 202207L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_reserve_hint 202502L // also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_slide 202202L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_starts_ends_with 202106L // also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]")#define __cpp_lib_ranges_stride 202207L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_to_container 202202L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_to_input 202502L // freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")#define __cpp_lib_ranges_zip 202110L// freestanding, also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]"), [<tuple>](tuple.syn#header:%3ctuple%3e "22.4.2 Header <tuple> synopsis [tuple.syn]"), [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_ratio 202306L // freestanding, also in [<ratio>](ratio.syn#header:%3cratio%3e "21.5.2 Header <ratio> synopsis [ratio.syn]")#define __cpp_lib_raw_memory_algorithms 202411L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_rcu 202306L // also in [<rcu>](rcu.syn#header:%3crcu%3e "32.11.2.2 Header <rcu> synopsis [rcu.syn]")#define __cpp_lib_reference_from_temporary 202202L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_reference_wrapper 202403L // freestanding, also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_reflection 202506L // also in [<meta>](meta.syn#header:%3cmeta%3e "21.4.1 Header <meta> synopsis [meta.syn]")#define __cpp_lib_remove_cvref 201711L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_result_of_sfinae 201210L// freestanding, also in [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]"), [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_robust_nonmodifying_seq_ops 201304L // also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]")#define __cpp_lib_sample 201603L // also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]")#define __cpp_lib_saturation_arithmetic 202311L // also in [<numeric>](numeric.ops.overview#header:%3cnumeric%3e "26.9 Header <numeric> synopsis [numeric.ops.overview]")#define __cpp_lib_scoped_lock 201703L // also in [<mutex>](mutex.syn#header:%3cmutex%3e "32.6.2 Header <mutex> synopsis [mutex.syn]")#define __cpp_lib_semaphore 201907L // also in [<semaphore>](semaphore.syn#header:%3csemaphore%3e "32.8.2 Header <semaphore> synopsis [semaphore.syn]")#define __cpp_lib_senders 202506L // also in [<execution>](execution.syn#header:%3cexecution%3e "33.4 Header <execution> synopsis [execution.syn]")#define __cpp_lib_shared_mutex 201505L // also in [<shared_mutex>](shared.mutex.syn#header:%3cshared_mutex%3e "32.6.3 Header <shared_­mutex> synopsis [shared.mutex.syn]")#define __cpp_lib_shared_ptr_arrays 201707L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_shared_ptr_weak_type 201606L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_shared_timed_mutex 201402L // also in [<shared_mutex>](shared.mutex.syn#header:%3cshared_mutex%3e "32.6.3 Header <shared_­mutex> synopsis [shared.mutex.syn]")#define __cpp_lib_shift 202202L // also in [<algorithm>](algorithm.syn#header:%3calgorithm%3e "26.4 Header <algorithm> synopsis [algorithm.syn]")#define __cpp_lib_simd 202506L // also in [<simd>](simd.syn#header:%3csimd%3e "29.10.3 Header <simd> synopsis [simd.syn]")#define __cpp_lib_simd_complex 202502L // also in [<simd>](simd.syn#header:%3csimd%3e "29.10.3 Header <simd> synopsis [simd.syn]")#define __cpp_lib_simd_permutations 202506L // also in [<simd>](simd.syn#header:%3csimd%3e "29.10.3 Header <simd> synopsis [simd.syn]")#define __cpp_lib_smart_ptr_for_overwrite 202002L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_smart_ptr_owner_equality 202306L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_source_location 201907L // freestanding, also in [<source_location>](source.location.syn#header:%3csource_location%3e "17.8.1 Header <source_­location> synopsis [source.location.syn]")#define __cpp_lib_span 202311L // freestanding, also in [<span>](span.syn#header:%3cspan%3e "23.7.2.1 Header <span> synopsis [span.syn]")#define __cpp_lib_span_initializer_list 202311L // freestanding, also in [<span>](span.syn#header:%3cspan%3e "23.7.2.1 Header <span> synopsis [span.syn]")#define __cpp_lib_spanstream 202106L // also in [<spanstream>](span.streams.overview#header:%3cspanstream%3e "31.9.1 Overview [span.streams.overview]")#define __cpp_lib_ssize 201902L // freestanding, also in [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]")#define __cpp_lib_sstream_from_string_view 202306L // also in [<sstream>](sstream.syn#header:%3csstream%3e "31.8.1 Header <sstream> synopsis [sstream.syn]")#define __cpp_lib_stacktrace 202011L // also in [<stacktrace>](stacktrace.syn#header:%3cstacktrace%3e "19.6.2 Header <stacktrace> synopsis [stacktrace.syn]")#define __cpp_lib_start_lifetime_as 202207L // freestanding, also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_starts_ends_with 201711L // also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]"), [<string_view>](string.view.synop#header:%3cstring_view%3e "27.3.2 Header <string_­view> synopsis [string.view.synop]")#define __cpp_lib_stdatomic_h 202011L // also in [<stdatomic.h>](stdatomic.h.syn#header:%3cstdatomic.h%3e "32.5.12 C compatibility [stdatomic.h.syn]")#define __cpp_lib_string_contains 202011L // also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]"), [<string_view>](string.view.synop#header:%3cstring_view%3e "27.3.2 Header <string_­view> synopsis [string.view.synop]")#define __cpp_lib_string_resize_and_overwrite 202110L // also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]")#define __cpp_lib_string_subview 202506L // also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]"), [<string_view>](string.view.synop#header:%3cstring_view%3e "27.3.2 Header <string_­view> synopsis [string.view.synop]")#define __cpp_lib_string_udls 201304L // also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]")#define __cpp_lib_string_view 202403L // also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]"), [<string_view>](string.view.synop#header:%3cstring_view%3e "27.3.2 Header <string_­view> synopsis [string.view.synop]")#define __cpp_lib_submdspan 202411L // freestanding, also in [<mdspan>](mdspan.syn#header:%3cmdspan%3e "23.7.3.2 Header <mdspan> synopsis [mdspan.syn]")#define __cpp_lib_syncbuf 201803L // also in [<syncstream>](syncstream.syn#header:%3csyncstream%3e "31.11.1 Header <syncstream> synopsis [syncstream.syn]")#define __cpp_lib_task 202506L // also in [<execution>](execution.syn#header:%3cexecution%3e "33.4 Header <execution> synopsis [execution.syn]")#define __cpp_lib_text_encoding 202306L // also in [<text_encoding>](text.encoding.syn#header:%3ctext_encoding%3e "28.4.1 Header <text_­encoding> synopsis [text.encoding.syn]")#define __cpp_lib_three_way_comparison 201907L // freestanding, also in [<compare>](compare.syn#header:%3ccompare%3e "17.12.1 Header <compare> synopsis [compare.syn]")#define __cpp_lib_to_address 201711L // freestanding, also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_to_array 201907L // freestanding, also in [<array>](array.syn#header:%3carray%3e "23.3.2 Header <array> synopsis [array.syn]")#define __cpp_lib_to_chars 202306L // also in [<charconv>](charconv.syn#header:%3ccharconv%3e "28.2.1 Header <charconv> synopsis [charconv.syn]")#define __cpp_lib_to_string 202306L // also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]")#define __cpp_lib_to_underlying 202102L // freestanding, also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_transformation_trait_aliases 201304L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_transparent_operators 201510L// freestanding, also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]"), [<functional>](functional.syn#header:%3cfunctional%3e "22.10.2 Header <functional> synopsis [functional.syn]")#define __cpp_lib_trivially_relocatable 202502L// freestanding, also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]"), [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_tuple_element_t 201402L // freestanding, also in [<tuple>](tuple.syn#header:%3ctuple%3e "22.4.2 Header <tuple> synopsis [tuple.syn]")#define __cpp_lib_tuple_like 202311L// also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]"), [<tuple>](tuple.syn#header:%3ctuple%3e "22.4.2 Header <tuple> synopsis [tuple.syn]"), [<map>](associative.map.syn#header:%3cmap%3e "23.4.2 Header <map> synopsis [associative.map.syn]"), [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]")#define __cpp_lib_tuples_by_type 201304L // freestanding, also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]"), [<tuple>](tuple.syn#header:%3ctuple%3e "22.4.2 Header <tuple> synopsis [tuple.syn]")#define __cpp_lib_type_identity 201806L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_type_order 202506L // also in [<compare>](compare.syn#header:%3ccompare%3e "17.12.1 Header <compare> synopsis [compare.syn]")#define __cpp_lib_type_trait_variable_templates 201510L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_uncaught_exceptions 201411L // freestanding, also in [<exception>](support.exception.general#header:%3cexception%3e "17.9.1 General [support.exception.general]")#define __cpp_lib_unordered_map_try_emplace 201411L // also in [<unordered_map>](unord.map.syn#header:%3cunordered_map%3e "23.5.2 Header <unordered_­map> synopsis [unord.map.syn]")#define __cpp_lib_unreachable 202202L // freestanding, also in [<utility>](utility.syn#header:%3cutility%3e "22.2.1 Header <utility> synopsis [utility.syn]")#define __cpp_lib_unwrap_ref 201811L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")#define __cpp_lib_variant 202306L // also in [<variant>](variant.syn#header:%3cvariant%3e "22.6.2 Header <variant> synopsis [variant.syn]")#define __cpp_lib_void_t 201411L // freestanding, also in [<type_traits>](meta.type.synop#header:%3ctype_traits%3e "21.3.3 Header <type_­traits> synopsis [meta.type.synop]")

[3](#version.syn-3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L867)

Additionally, each of the following macros is defined in a hardened implementation:#define __cpp_lib_hardened_array 202502L // also in [<array>](array.syn#header:%3carray%3e "23.3.2 Header <array> synopsis [array.syn]")#define __cpp_lib_hardened_basic_stacktrace 202506L // also in [<stacktrace>](stacktrace.syn#header:%3cstacktrace%3e "19.6.2 Header <stacktrace> synopsis [stacktrace.syn]")#define __cpp_lib_hardened_basic_string 202502L // also in [<string>](string.syn#header:%3cstring%3e "27.4.2 Header <string> synopsis [string.syn]")#define __cpp_lib_hardened_basic_string_view 202502L // also in [<string_view>](string.view.synop#header:%3cstring_view%3e "27.3.2 Header <string_­view> synopsis [string.view.synop]")#define __cpp_lib_hardened_bitset 202502L // also in [<bitset>](bitset.syn#header:%3cbitset%3e "22.9.1 Header <bitset> synopsis [bitset.syn]")#define __cpp_lib_hardened_common_iterator 202506L // also in [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]")#define __cpp_lib_hardened_counted_iterator 202506L // also in [<iterator>](iterator.synopsis#header:%3citerator%3e "24.2 Header <iterator>&nbsp;synopsis [iterator.synopsis]")#define __cpp_lib_hardened_deque 202502L // also in [<deque>](deque.syn#header:%3cdeque%3e "23.3.4 Header <deque> synopsis [deque.syn]")#define __cpp_lib_hardened_expected 202502L // also in [<expected>](expected.syn#header:%3cexpected%3e "22.8.2 Header <expected> synopsis [expected.syn]")#define __cpp_lib_hardened_forward_list 202502L // also in [<forward_list>](forward.list.syn#header:%3cforward_list%3e "23.3.6 Header <forward_­list> synopsis [forward.list.syn]")#define __cpp_lib_hardened_inplace_vector 202502L // also in [<inplace_vector>](inplace.vector.syn#header:%3cinplace_vector%3e "23.3.15 Header <inplace_­vector> synopsis [inplace.vector.syn]")#define __cpp_lib_hardened_list 202502L // also in [<list>](list.syn#header:%3clist%3e "23.3.10 Header <list> synopsis [list.syn]")#define __cpp_lib_hardened_mdspan 202502L // also in [<mdspan>](mdspan.syn#header:%3cmdspan%3e "23.7.3.2 Header <mdspan> synopsis [mdspan.syn]")#define __cpp_lib_hardened_optional 202502L // also in [<optional>](optional.syn#header:%3coptional%3e "22.5.2 Header <optional> synopsis [optional.syn]")#define __cpp_lib_hardened_shared_ptr_array 202506L // also in [<memory>](memory.syn#header:%3cmemory%3e "20.2.2 Header <memory> synopsis [memory.syn]")#define __cpp_lib_hardened_span 202502L // also in [<span>](span.syn#header:%3cspan%3e "23.7.2.1 Header <span> synopsis [span.syn]")#define __cpp_lib_hardened_valarray 202502L // also in [<valarray>](valarray.syn#header:%3cvalarray%3e "29.6.1 Header <valarray> synopsis [valarray.syn]")#define __cpp_lib_hardened_vector 202502L // also in [<vector>](vector.syn#header:%3cvector%3e "23.3.12 Header <vector> synopsis [vector.syn]")#define __cpp_lib_hardened_view_interface 202506L // also in [<ranges>](ranges.syn#header:%3cranges%3e "25.2 Header <ranges> synopsis [ranges.syn]")

[4](#version.syn-4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L891)

The macro __cpp_lib_freestanding_operator_new is defined to
the integer literal 202306L if all the default versions of the replaceable global allocation functions meet
the requirements of a hosted implementation, and
to the integer literal 0 otherwise ([[new.delete]](new.delete "17.6.3 Storage allocation and deallocation"))[.](#version.syn-4.sentence-1)

[5](#version.syn-5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L898)

*Recommended practice*: Freestanding implementations should only define a macro from [<version>](#header:%3cversion%3e "17.3.2 Header <version> synopsis [version.syn]") if the implementation provides the corresponding facility in its entirety[.](#version.syn-5.sentence-1)

[6](#version.syn-6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L903)

*Recommended practice*: A non-hardened implementation should not define macros from [<version>](#header:%3cversion%3e "17.3.2 Header <version> synopsis [version.syn]") required for hardened implementations[.](#version.syn-6.sentence-1)

### [17.3.3](#limits.syn) Header <limits> synopsis [[limits.syn]](limits.syn)

// all freestandingnamespace std {// [[round.style]](#round.style "17.3.4 Enum float_­round_­style"), enumeration float_round_styleenum float_round_style; // [[numeric.limits]](#numeric.limits "17.3.5 Class template numeric_­limits"), class template numeric_limitstemplate<class T> class numeric_limits; template<class T> class numeric_limits<const T>; template<class T> class numeric_limits<volatile T>; template<class T> class numeric_limits<const volatile T>; template<> class numeric_limits<bool>; template<> class numeric_limits<char>; template<> class numeric_limits<signed char>; template<> class numeric_limits<unsigned char>; template<> class numeric_limits<char8_t>; template<> class numeric_limits<char16_t>; template<> class numeric_limits<char32_t>; template<> class numeric_limits<wchar_t>; template<> class numeric_limits<short>; template<> class numeric_limits<int>; template<> class numeric_limits<long>; template<> class numeric_limits<long long>; template<> class numeric_limits<unsigned short>; template<> class numeric_limits<unsigned int>; template<> class numeric_limits<unsigned long>; template<> class numeric_limits<unsigned long long>; template<> class numeric_limits<float>; template<> class numeric_limits<double>; template<> class numeric_limits<long double>;}

### [17.3.4](#round.style) Enum float_round_style [[round.style]](round.style)

[🔗](#lib:float_round_style_)

namespace std {enum float_round_style { round_indeterminate = -1,
 round_toward_zero = 0,
 round_to_nearest = 1,
 round_toward_infinity = 2,
 round_toward_neg_infinity = 3};}

[1](#round.style-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L968)

The rounding mode for floating-point arithmetic is characterized by the
values:

- [(1.1)](#round.style-1.1)

round_indeterminate if the rounding style is indeterminable

- [(1.2)](#round.style-1.2)

round_toward_zero if the rounding style is toward zero

- [(1.3)](#round.style-1.3)

round_to_nearest if the rounding style is to the nearest representable value

- [(1.4)](#round.style-1.4)

round_toward_infinity if the rounding style is toward infinity

- [(1.5)](#round.style-1.5)

round_toward_neg_infinity if the rounding style is toward negative infinity

### [17.3.5](#numeric.limits) Class template numeric_limits [[numeric.limits]](numeric.limits)

#### [17.3.5.1](#numeric.limits.general) General [[numeric.limits.general]](numeric.limits.general)

[1](#numeric.limits.general-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L998)

Thenumeric_limits class template provides a C++ program with information about various properties of
the implementation's representation of the
arithmetic types[.](#numeric.limits.general-1.sentence-1)

[🔗](#lib:numeric_limits__)

namespace std {template<class T> class numeric_limits {public:static constexpr bool is_specialized = false; static constexpr T min() noexcept { return T(); }static constexpr T max() noexcept { return T(); }static constexpr T lowest() noexcept { return T(); }static constexpr int digits = 0; static constexpr int digits10 = 0; static constexpr int max_digits10 = 0; static constexpr bool is_signed = false; static constexpr bool is_integer = false; static constexpr bool is_exact = false; static constexpr int radix = 0; static constexpr T epsilon() noexcept { return T(); }static constexpr T round_error() noexcept { return T(); }static constexpr int min_exponent = 0; static constexpr int min_exponent10 = 0; static constexpr int max_exponent = 0; static constexpr int max_exponent10 = 0; static constexpr bool has_infinity = false; static constexpr bool has_quiet_NaN = false; static constexpr bool has_signaling_NaN = false; static constexpr T infinity() noexcept { return T(); }static constexpr T quiet_NaN() noexcept { return T(); }static constexpr T signaling_NaN() noexcept { return T(); }static constexpr T denorm_min() noexcept { return T(); }static constexpr bool is_iec559 = false; static constexpr bool is_bounded = false; static constexpr bool is_modulo = false; static constexpr bool traps = false; static constexpr bool tinyness_before = false; static constexpr float_round_style round_style = round_toward_zero; };}

[2](#numeric.limits.general-2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1050)

For all members declaredstatic constexpr in thenumeric_limits template, specializations shall define these values in such a way
that they are usable as
constant expressions[.](#numeric.limits.general-2.sentence-1)

[3](#numeric.limits.general-3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1059)

For thenumeric_limits primary template, all data members are value-initialized and all
member functions return a value-initialized object[.](#numeric.limits.general-3.sentence-1)

[*Note [1](#numeric.limits.general-note-1)*:

This means all members have zero or false values
unless numeric_limits is specialized for a type[.](#numeric.limits.general-3.sentence-2)

— *end note*]

[4](#numeric.limits.general-4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1069)

Specializations shall be provided for each
arithmetic type,
both floating-point and integer, includingbool[.](#numeric.limits.general-4.sentence-1)

The memberis_specialized shall betrue for all such specializations ofnumeric_limits[.](#numeric.limits.general-4.sentence-2)

[5](#numeric.limits.general-5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1081)

The value of each member of a specialization ofnumeric_limits on a cv-qualified typecv T shall be equal to the value of the corresponding member of
the specialization on the unqualified type T[.](#numeric.limits.general-5.sentence-1)

[6](#numeric.limits.general-6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1087)

Non-arithmetic standard types, such as[complex<T>](complex "29.4.3 Class template complex [complex]"), shall not have specializations[.](#numeric.limits.general-6.sentence-1)

#### [17.3.5.2](#numeric.limits.members) numeric_limits members [[numeric.limits.members]](numeric.limits.members)

[1](#numeric.limits.members-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1093)

Each member function defined in this subclause is signal-safe ([[support.signal]](support.signal "17.14.5 Signal handlers"))[.](#numeric.limits.members-1.sentence-1)

[*Note [1](#numeric.limits.members-note-1)*:

The arithmetic specification described in ISO/IEC 10967-1:2012 is
commonly termed LIA-1[.](#numeric.limits.members-1.sentence-2)

— *end note*]

[🔗](#lib:min,numeric_limits)

`static constexpr T min() noexcept;
`

[2](#numeric.limits.members-2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1108)

Minimum finite value[.](#numeric.limits.members-2.sentence-1)[161](#footnote-161 "Equivalent to CHAR_­MIN, SHRT_­MIN, FLT_­MIN, DBL_­MIN, etc.")

[3](#numeric.limits.members-3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1116)

For floating-point types with subnormal numbers, returns the minimum positive
normalized value[.](#numeric.limits.members-3.sentence-1)

[4](#numeric.limits.members-4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1120)

Meaningful for all specializations in whichis_bounded != false,
oris_bounded == false && is_signed == false[.](#numeric.limits.members-4.sentence-1)

[🔗](#lib:max,numeric_limits)

`static constexpr T max() noexcept;
`

[5](#numeric.limits.members-5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1133)

Maximum finite value[.](#numeric.limits.members-5.sentence-1)[162](#footnote-162 "Equivalent to CHAR_­MAX, SHRT_­MAX, FLT_­MAX, DBL_­MAX, etc.")

[6](#numeric.limits.members-6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1140)

Meaningful for all specializations in whichis_bounded != false[.](#numeric.limits.members-6.sentence-1)

[🔗](#lib:lowest,numeric_limits)

`static constexpr T lowest() noexcept;
`

[7](#numeric.limits.members-7)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1151)

A finite value x such that there is no other finite
value y where y < x[.](#numeric.limits.members-7.sentence-1)[163](#footnote-163 "lowest() is necessary because not all floating-point representations have a smallest (most negative) value that is the negative of the largest (most positive) finite value.")

[8](#numeric.limits.members-8)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1160)

Meaningful for all specializations in which is_bounded != false[.](#numeric.limits.members-8.sentence-1)

[🔗](#lib:digits,numeric_limits)

`static constexpr int digits;
`

[9](#numeric.limits.members-9)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1170)

Number ofradix digits that can be represented without change[.](#numeric.limits.members-9.sentence-1)

[10](#numeric.limits.members-10)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1175)

For integer types, the number of non-sign bits in the representation[.](#numeric.limits.members-10.sentence-1)

[11](#numeric.limits.members-11)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1178)

For floating-point types, the number of radix digits in the
significand[.](#numeric.limits.members-11.sentence-1)[164](#footnote-164 "Equivalent to FLT_­MANT_­DIG, DBL_­MANT_­DIG, LDBL_­MANT_­DIG.")

[🔗](#lib:digits10,numeric_limits)

`static constexpr int digits10;
`

[12](#numeric.limits.members-12)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1193)

Number of base 10 digits that can be represented without
change[.](#numeric.limits.members-12.sentence-1)[165](#footnote-165 "Equivalent to FLT_­DIG, DBL_­DIG, LDBL_­DIG.")

[13](#numeric.limits.members-13)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1201)

Meaningful for all specializations in whichis_bounded != false[.](#numeric.limits.members-13.sentence-1)

[🔗](#lib:max_digits10,numeric_limits)

`static constexpr int max_digits10;
`

[14](#numeric.limits.members-14)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1212)

Number of base 10 digits required to ensure that values which
differ are always differentiated[.](#numeric.limits.members-14.sentence-1)

[15](#numeric.limits.members-15)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1216)

Meaningful for all floating-point types[.](#numeric.limits.members-15.sentence-1)

[🔗](#lib:is_signed,numeric_limits)

`static constexpr bool is_signed;
`

[16](#numeric.limits.members-16)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1226)

true if the type is signed[.](#numeric.limits.members-16.sentence-1)

[17](#numeric.limits.members-17)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1229)

Meaningful for all specializations[.](#numeric.limits.members-17.sentence-1)

[🔗](#lib:is_integer,numeric_limits)

`static constexpr bool is_integer;
`

[18](#numeric.limits.members-18)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1239)

true if the type is integer[.](#numeric.limits.members-18.sentence-1)

[19](#numeric.limits.members-19)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1242)

Meaningful for all specializations[.](#numeric.limits.members-19.sentence-1)

[🔗](#lib:is_exact,numeric_limits)

`static constexpr bool is_exact;
`

[20](#numeric.limits.members-20)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1252)

true if the type uses an exact representation[.](#numeric.limits.members-20.sentence-1)

All integer types are exact, but not all exact types are integer[.](#numeric.limits.members-20.sentence-2)

For example, rational and fixed-exponent representations are exact but not integer[.](#numeric.limits.members-20.sentence-3)

[21](#numeric.limits.members-21)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1257)

Meaningful for all specializations[.](#numeric.limits.members-21.sentence-1)

[🔗](#lib:radix,numeric_limits)

`static constexpr int radix;
`

[22](#numeric.limits.members-22)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1267)

For floating-point types, specifies the base or radix of the exponent representation
(often 2)[.](#numeric.limits.members-22.sentence-1)[166](#footnote-166 "Equivalent to FLT_­RADIX.")

[23](#numeric.limits.members-23)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1274)

For integer types, specifies the base of the
representation[.](#numeric.limits.members-23.sentence-1)[167](#footnote-167 "Distinguishes types with bases other than 2 (e.g., BCD).")

[24](#numeric.limits.members-24)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1281)

Meaningful for all specializations[.](#numeric.limits.members-24.sentence-1)

[🔗](#lib:epsilon,numeric_limits)

`static constexpr T epsilon() noexcept;
`

[25](#numeric.limits.members-25)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1291)

Machine epsilon: the difference between 1 and the least value greater than 1
that is representable[.](#numeric.limits.members-25.sentence-1)[168](#footnote-168 "Equivalent to FLT_­EPSILON, DBL_­EPSILON, LDBL_­EPSILON.")

[26](#numeric.limits.members-26)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1298)

Meaningful for all floating-point types[.](#numeric.limits.members-26.sentence-1)

[🔗](#lib:round_error,numeric_limits)

`static constexpr T round_error() noexcept;
`

[27](#numeric.limits.members-27)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1308)

Measure of the maximum rounding error[.](#numeric.limits.members-27.sentence-1)[169](#footnote-169 "Rounding error is described in ISO/IEC 10967-1:2012 Section 5.2.4 and Annex C Rationale Section C.5.2.4 — Rounding and rounding constants.")

[🔗](#lib:min_exponent,numeric_limits)

`static constexpr int min_exponent;
`

[28](#numeric.limits.members-28)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1322)

Minimum negative integer such thatradix raised to the power of one less than that integer is a normalized floating-point
number[.](#numeric.limits.members-28.sentence-1)[170](#footnote-170 "Equivalent to FLT_­MIN_­EXP, DBL_­MIN_­EXP, LDBL_­MIN_­EXP.")

[29](#numeric.limits.members-29)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1332)

Meaningful for all floating-point types[.](#numeric.limits.members-29.sentence-1)

[🔗](#lib:min_exponent10,numeric_limits)

`static constexpr int min_exponent10;
`

[30](#numeric.limits.members-30)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1342)

Minimum negative integer such that 10 raised to that power is in the range
of normalized floating-point numbers[.](#numeric.limits.members-30.sentence-1)[171](#footnote-171 "Equivalent to FLT_­MIN_­10_­EXP, DBL_­MIN_­10_­EXP, LDBL_­MIN_­10_­EXP.")

[31](#numeric.limits.members-31)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1350)

Meaningful for all floating-point types[.](#numeric.limits.members-31.sentence-1)

[🔗](#lib:max_exponent,numeric_limits)

`static constexpr int max_exponent;
`

[32](#numeric.limits.members-32)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1360)

Maximum positive integer such thatradix raised to the power one less than that integer is a representable finite
floating-point number[.](#numeric.limits.members-32.sentence-1)[172](#footnote-172 "Equivalent to FLT_­MAX_­EXP, DBL_­MAX_­EXP, LDBL_­MAX_­EXP.")

[33](#numeric.limits.members-33)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1370)

Meaningful for all floating-point types[.](#numeric.limits.members-33.sentence-1)

[🔗](#lib:max_exponent10,numeric_limits)

`static constexpr int max_exponent10;
`

[34](#numeric.limits.members-34)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1380)

Maximum positive integer such that 10 raised to that power is in the
range of representable finite floating-point numbers[.](#numeric.limits.members-34.sentence-1)[173](#footnote-173 "Equivalent to FLT_­MAX_­10_­EXP, DBL_­MAX_­10_­EXP, LDBL_­MAX_­10_­EXP.")

[35](#numeric.limits.members-35)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1388)

Meaningful for all floating-point types[.](#numeric.limits.members-35.sentence-1)

[🔗](#lib:has_infinity,numeric_limits)

`static constexpr bool has_infinity;
`

[36](#numeric.limits.members-36)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1398)

true if the type has a representation for positive infinity[.](#numeric.limits.members-36.sentence-1)

[37](#numeric.limits.members-37)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1401)

Meaningful for all floating-point types[.](#numeric.limits.members-37.sentence-1)

[38](#numeric.limits.members-38)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1404)

Shall betrue for all specializations in whichis_iec559 != false[.](#numeric.limits.members-38.sentence-1)

[🔗](#lib:has_quiet_NaN,numeric_limits)

`static constexpr bool has_quiet_NaN;
`

[39](#numeric.limits.members-39)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1417)

true if the type has a representation for a quiet (non-signaling) “Not a
Number”[.](#numeric.limits.members-39.sentence-1)[174](#footnote-174 "Required by ISO/IEC 10967-1:2012.")

[40](#numeric.limits.members-40)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1424)

Meaningful for all floating-point types[.](#numeric.limits.members-40.sentence-1)

[41](#numeric.limits.members-41)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1427)

Shall betrue for all specializations in whichis_iec559 != false[.](#numeric.limits.members-41.sentence-1)

[🔗](#lib:has_signaling_NaN,numeric_limits)

`static constexpr bool has_signaling_NaN;
`

[42](#numeric.limits.members-42)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1440)

true if the type has a representation for a signaling “Not a Number”[.](#numeric.limits.members-42.sentence-1)[175](#footnote-175 "Required by ISO/IEC 10967-1:2012.")

[43](#numeric.limits.members-43)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1446)

Meaningful for all floating-point types[.](#numeric.limits.members-43.sentence-1)

[44](#numeric.limits.members-44)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1449)

Shall betrue for all specializations in whichis_iec559 != false[.](#numeric.limits.members-44.sentence-1)

[🔗](#lib:infinity,numeric_limits)

`static constexpr T infinity() noexcept;
`

[45](#numeric.limits.members-45)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1462)

Representation of positive infinity, if available[.](#numeric.limits.members-45.sentence-1)[176](#footnote-176 "Required by ISO/IEC 10967-1:2012.")

[46](#numeric.limits.members-46)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1468)

Meaningful for all specializations for whichhas_infinity != false[.](#numeric.limits.members-46.sentence-1)

Required in specializations for whichis_iec559 != false[.](#numeric.limits.members-46.sentence-2)

[🔗](#lib:quiet_NaN,numeric_limits)

`static constexpr T quiet_NaN() noexcept;
`

[47](#numeric.limits.members-47)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1481)

Representation of a quiet “Not a Number”, if available[.](#numeric.limits.members-47.sentence-1)[177](#footnote-177 "Required by ISO/IEC 10967-1:2012.")

[48](#numeric.limits.members-48)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1487)

Meaningful for all specializations for whichhas_quiet_NaN != false[.](#numeric.limits.members-48.sentence-1)

Required in specializations for whichis_iec559 != false[.](#numeric.limits.members-48.sentence-2)

[🔗](#lib:signaling_NaN,numeric_limits)

`static constexpr T signaling_NaN() noexcept;
`

[49](#numeric.limits.members-49)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1500)

Representation of a signaling “Not a Number”, if available[.](#numeric.limits.members-49.sentence-1)[178](#footnote-178 "Required by ISO/IEC 10967-1:2012.")

[50](#numeric.limits.members-50)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1506)

Meaningful for all specializations for whichhas_signaling_NaN != false[.](#numeric.limits.members-50.sentence-1)

Required in specializations for whichis_iec559 != false[.](#numeric.limits.members-50.sentence-2)

[🔗](#lib:denorm_min,numeric_limits)

`static constexpr T denorm_min() noexcept;
`

[51](#numeric.limits.members-51)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1520)

Minimum positive subnormal value, if available[.](#numeric.limits.members-51.sentence-1)[179](#footnote-179 "Required by ISO/IEC 10967-1:2012.")

Otherwise, minimum positive normalized value[.](#numeric.limits.members-51.sentence-2)

[52](#numeric.limits.members-52)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1527)

Meaningful for all floating-point types[.](#numeric.limits.members-52.sentence-1)

[🔗](#lib:is_iec559,numeric_limits)

`static constexpr bool is_iec559;
`

[53](#numeric.limits.members-53)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1537)

true if and only if the type adheres to ISO/IEC 60559[.](#numeric.limits.members-53.sentence-1)[180](#footnote-180 "ISO/IEC 60559:2020 is the same as IEEE 754-2019.")

[*Note [2](#numeric.limits.members-note-2)*:

The value is true for any of the typesfloat16_t, float32_t, float64_t, or float128_t,
if present ([[basic.extended.fp]](basic.extended.fp "6.9.3 Optional extended floating-point types"))[.](#numeric.limits.members-53.sentence-2)

— *end note*]

[54](#numeric.limits.members-54)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1548)

Meaningful for all floating-point types[.](#numeric.limits.members-54.sentence-1)

[🔗](#lib:is_bounded,numeric_limits)

`static constexpr bool is_bounded;
`

[55](#numeric.limits.members-55)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1558)

true if the set of values representable by the type is finite[.](#numeric.limits.members-55.sentence-1)[181](#footnote-181 "Required by ISO/IEC 10967-1:2012.")

[*Note [3](#numeric.limits.members-note-3)*:

All fundamental types ([[basic.fundamental]](basic.fundamental "6.9.2 Fundamental types")) are bounded[.](#numeric.limits.members-55.sentence-2)

This member would be false for arbitrary
precision types[.](#numeric.limits.members-55.sentence-3)

— *end note*]

[56](#numeric.limits.members-56)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1568)

Meaningful for all specializations[.](#numeric.limits.members-56.sentence-1)

[🔗](#lib:is_modulo,numeric_limits)

`static constexpr bool is_modulo;
`

[57](#numeric.limits.members-57)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1578)

true if the type is modulo[.](#numeric.limits.members-57.sentence-1)[182](#footnote-182 "Required by ISO/IEC 10967-1:2012.")

A type is modulo if, for any operation involving +, -, or* on values of that type whose result would fall outside the range
[min(), max()], the value returned differs from the true value by an
integer multiple of max() - min() + 1[.](#numeric.limits.members-57.sentence-2)

[58](#numeric.limits.members-58)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1588)

[*Example [1](#numeric.limits.members-example-1)*:

is_modulo is false for signed integer types ([[basic.fundamental]](basic.fundamental "6.9.2 Fundamental types"))
unless an implementation, as an extension to this document,
defines signed integer overflow to wrap[.](#numeric.limits.members-58.sentence-1)

— *end example*]

[59](#numeric.limits.members-59)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1595)

Meaningful for all specializations[.](#numeric.limits.members-59.sentence-1)

[🔗](#lib:traps,numeric_limits)

`static constexpr bool traps;
`

[60](#numeric.limits.members-60)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1605)

true if, at the start of the program, there exists a value of the type that would cause
an arithmetic operation using that value to trap[.](#numeric.limits.members-60.sentence-1)[183](#footnote-183 "Required by ISO/IEC 10967-1:2012.")

[61](#numeric.limits.members-61)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1613)

Meaningful for all specializations[.](#numeric.limits.members-61.sentence-1)

[🔗](#lib:tinyness_before,numeric_limits)

`static constexpr bool tinyness_before;
`

[62](#numeric.limits.members-62)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1623)

true if tinyness is detected before rounding[.](#numeric.limits.members-62.sentence-1)[184](#footnote-184 "Refer to ISO/IEC 60559. Required by ISO/IEC 10967-1:2012.")

[63](#numeric.limits.members-63)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1632)

Meaningful for all floating-point types[.](#numeric.limits.members-63.sentence-1)

[🔗](#lib:round_style,numeric_limits)

`static constexpr float_round_style round_style;
`

[64](#numeric.limits.members-64)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1642)

The rounding style for the type[.](#numeric.limits.members-64.sentence-1)[185](#footnote-185 "Equivalent to FLT_­ROUNDS. Required by ISO/IEC 10967-1:2012.")

[65](#numeric.limits.members-65)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1649)

Meaningful for all floating-point types[.](#numeric.limits.members-65.sentence-1)

Specializations for integer types shall returnround_toward_zero[.](#numeric.limits.members-65.sentence-2)

[161)](#footnote-161)[161)](#footnoteref-161)

Equivalent to CHAR_MIN, SHRT_MIN,FLT_MIN, DBL_MIN, etc[.](#footnote-161.sentence-1)

[162)](#footnote-162)[162)](#footnoteref-162)

Equivalent to CHAR_MAX, SHRT_MAX,FLT_MAX, DBL_MAX, etc[.](#footnote-162.sentence-1)

[163)](#footnote-163)[163)](#footnoteref-163)

lowest() is necessary because not all
floating-point representations have a smallest (most negative) value that is
the negative of the largest (most positive) finite value[.](#footnote-163.sentence-1)

[164)](#footnote-164)[164)](#footnoteref-164)

Equivalent to FLT_MANT_DIG, DBL_MANT_DIG,LDBL_MANT_DIG[.](#footnote-164.sentence-1)

[165)](#footnote-165)[165)](#footnoteref-165)

Equivalent to FLT_DIG, DBL_DIG,LDBL_DIG[.](#footnote-165.sentence-1)

[166)](#footnote-166)[166)](#footnoteref-166)

Equivalent to FLT_RADIX[.](#footnote-166.sentence-1)

[167)](#footnote-167)[167)](#footnoteref-167)

Distinguishes types with bases other than 2 (e.g., BCD)[.](#footnote-167.sentence-1)

[168)](#footnote-168)[168)](#footnoteref-168)

Equivalent to FLT_EPSILON, DBL_EPSILON, LDBL_EPSILON[.](#footnote-168.sentence-1)

[169)](#footnote-169)[169)](#footnoteref-169)

Rounding error is described in ISO/IEC 10967-1:2012 Section 5.2.4 and
Annex C Rationale Section C.5.2.4 — Rounding and rounding constants[.](#footnote-169.sentence-1)

[170)](#footnote-170)[170)](#footnoteref-170)

Equivalent to FLT_MIN_EXP, DBL_MIN_EXP,LDBL_MIN_EXP[.](#footnote-170.sentence-1)

[171)](#footnote-171)[171)](#footnoteref-171)

Equivalent toFLT_MIN_10_EXP, DBL_MIN_10_EXP, LDBL_MIN_10_EXP[.](#footnote-171.sentence-1)

[172)](#footnote-172)[172)](#footnoteref-172)

Equivalent to FLT_MAX_EXP,DBL_MAX_EXP, LDBL_MAX_EXP[.](#footnote-172.sentence-1)

[173)](#footnote-173)[173)](#footnoteref-173)

Equivalent toFLT_MAX_10_EXP, DBL_MAX_10_EXP, LDBL_MAX_10_EXP[.](#footnote-173.sentence-1)

[174)](#footnote-174)[174)](#footnoteref-174)

Required by ISO/IEC 10967-1:2012[.](#footnote-174.sentence-1)

[175)](#footnote-175)[175)](#footnoteref-175)

Required by ISO/IEC 10967-1:2012[.](#footnote-175.sentence-1)

[176)](#footnote-176)[176)](#footnoteref-176)

Required by ISO/IEC 10967-1:2012[.](#footnote-176.sentence-1)

[177)](#footnote-177)[177)](#footnoteref-177)

Required by ISO/IEC 10967-1:2012[.](#footnote-177.sentence-1)

[178)](#footnote-178)[178)](#footnoteref-178)

Required by ISO/IEC 10967-1:2012[.](#footnote-178.sentence-1)

[179)](#footnote-179)[179)](#footnoteref-179)

Required by ISO/IEC 10967-1:2012[.](#footnote-179.sentence-1)

[180)](#footnote-180)[180)](#footnoteref-180)

ISO/IEC 60559:2020 is the same as IEEE 754-2019[.](#footnote-180.sentence-1)

[181)](#footnote-181)[181)](#footnoteref-181)

Required by ISO/IEC 10967-1:2012[.](#footnote-181.sentence-1)

[182)](#footnote-182)[182)](#footnoteref-182)

Required by ISO/IEC 10967-1:2012[.](#footnote-182.sentence-1)

[183)](#footnote-183)[183)](#footnoteref-183)

Required by ISO/IEC 10967-1:2012[.](#footnote-183.sentence-1)

[184)](#footnote-184)[184)](#footnoteref-184)

Refer to
ISO/IEC 60559[.](#footnote-184.sentence-1)

Required by ISO/IEC 10967-1:2012[.](#footnote-184.sentence-2)

[185)](#footnote-185)[185)](#footnoteref-185)

Equivalent to FLT_ROUNDS[.](#footnote-185.sentence-1)

Required by ISO/IEC 10967-1:2012[.](#footnote-185.sentence-2)

#### [17.3.5.3](#numeric.special) numeric_limits specializations [[numeric.special]](numeric.special)

[1](#numeric.special-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1657)

All members shall be provided for all specializations[.](#numeric.special-1.sentence-1)

However, many values are only required to be meaningful under certain
conditions
(for example,epsilon() is only meaningful ifis_integer isfalse)[.](#numeric.special-1.sentence-2)

Any value that is not “meaningful” shall be set to 0 orfalse[.](#numeric.special-1.sentence-3)

[2](#numeric.special-2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1670)

[*Example [1](#numeric.special-example-1)*: namespace std {template<> class numeric_limits<float> {public:static constexpr bool is_specialized = true; static constexpr float min() noexcept { return 1.17549435E-38F; }static constexpr float max() noexcept { return 3.40282347E+38F; }static constexpr float lowest() noexcept { return -3.40282347E+38F; }static constexpr int digits = 24; static constexpr int digits10 = 6; static constexpr int max_digits10 = 9; static constexpr bool is_signed = true; static constexpr bool is_integer = false; static constexpr bool is_exact = false; static constexpr int radix = 2; static constexpr float epsilon() noexcept { return 1.19209290E-07F; }static constexpr float round_error() noexcept { return 0.5F; }static constexpr int min_exponent = -125; static constexpr int min_exponent10 = - 37; static constexpr int max_exponent = +128; static constexpr int max_exponent10 = + 38; static constexpr bool has_infinity = true; static constexpr bool has_quiet_NaN = true; static constexpr bool has_signaling_NaN = true; static constexpr float infinity() noexcept { return *value*; }static constexpr float quiet_NaN() noexcept { return *value*; }static constexpr float signaling_NaN() noexcept { return *value*; }static constexpr float denorm_min() noexcept { return min(); }static constexpr bool is_iec559 = true; static constexpr bool is_bounded = true; static constexpr bool is_modulo = false; static constexpr bool traps = true; static constexpr bool tinyness_before = true; static constexpr float_round_style round_style = round_to_nearest; };} — *end example*]

[3](#numeric.special-3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1720)

The specialization forbool shall be provided as follows:

[🔗](#lib:numeric_limits%3cbool%3e)

namespace std {template<> class numeric_limits<bool> {public:static constexpr bool is_specialized = true; static constexpr bool min() noexcept { return false; }static constexpr bool max() noexcept { return true; }static constexpr bool lowest() noexcept { return false; }static constexpr int digits = 1; static constexpr int digits10 = 0; static constexpr int max_digits10 = 0; static constexpr bool is_signed = false; static constexpr bool is_integer = true; static constexpr bool is_exact = true; static constexpr int radix = 2; static constexpr bool epsilon() noexcept { return 0; }static constexpr bool round_error() noexcept { return 0; }static constexpr int min_exponent = 0; static constexpr int min_exponent10 = 0; static constexpr int max_exponent = 0; static constexpr int max_exponent10 = 0; static constexpr bool has_infinity = false; static constexpr bool has_quiet_NaN = false; static constexpr bool has_signaling_NaN = false; static constexpr bool infinity() noexcept { return 0; }static constexpr bool quiet_NaN() noexcept { return 0; }static constexpr bool signaling_NaN() noexcept { return 0; }static constexpr bool denorm_min() noexcept { return 0; }static constexpr bool is_iec559 = false; static constexpr bool is_bounded = true; static constexpr bool is_modulo = false; static constexpr bool traps = false; static constexpr bool tinyness_before = false; static constexpr float_round_style round_style = round_toward_zero; };}

### [17.3.6](#climits.syn) Header <climits> synopsis [[climits.syn]](climits.syn)

[🔗](#header:%3cclimits%3e)

// all freestanding#define BOOL_WIDTH *see below*#define CHAR_BIT *see below*#define CHAR_WIDTH *see below*#define SCHAR_WIDTH *see below*#define UCHAR_WIDTH *see below*#define USHRT_WIDTH *see below*#define SHRT_WIDTH *see below*#define UINT_WIDTH *see below*#define INT_WIDTH *see below*#define ULONG_WIDTH *see below*#define LONG_WIDTH *see below*#define ULLONG_WIDTH *see below*#define LLONG_WIDTH *see below*#define SCHAR_MIN *see below*#define SCHAR_MAX *see below*#define UCHAR_MAX *see below*#define CHAR_MIN *see below*#define CHAR_MAX *see below*#define MB_LEN_MAX *see below*#define SHRT_MIN *see below*#define SHRT_MAX *see below*#define USHRT_MAX *see below*#define INT_MIN *see below*#define INT_MAX *see below*#define UINT_MAX *see below*#define LONG_MIN *see below*#define LONG_MAX *see below*#define ULONG_MAX *see below*#define LLONG_MIN *see below*#define LLONG_MAX *see below*#define ULLONG_MAX *see below*

[1](#climits.syn-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1807)

The header [<climits>](#header:%3cclimits%3e "17.3.6 Header <climits> synopsis [climits.syn]") defines all macros the same as
the C standard library header [<limits.h>](support.c.headers.general#header:%3climits.h%3e "17.15.1 General [support.c.headers.general]"),
except that it does not define the macro BITINT_MAXWIDTH[.](#climits.syn-1.sentence-1)

[*Note [1](#climits.syn-note-1)*:

Except for the WIDTH macros, CHAR_BIT, and MB_LEN_MAX,
a macro referring to
an integer type T defines a constant whose type is the promoted
type of T ([[conv.prom]](conv.prom "7.3.7 Integral promotions"))[.](#climits.syn-1.sentence-2)

— *end note*]

See also: ISO/IEC 9899:2024, 5.2.4.2.1

### [17.3.7](#cfloat.syn) Header <cfloat> synopsis [[cfloat.syn]](cfloat.syn)

[🔗](#header:%3ccfloat%3e)

// all freestanding#define __STDC_VERSION_FLOAT_H__ 202311L#define FLT_ROUNDS *see below*#define FLT_EVAL_METHOD *see below*#define FLT_RADIX *see below*#define INFINITY *see below*#define NAN *see below*#define FLT_SNAN *see below*#define DBL_SNAN *see below*#define LDBL_SNAN *see below*#define FLT_MANT_DIG *see below*#define DBL_MANT_DIG *see below*#define LDBL_MANT_DIG *see below*#define FLT_DECIMAL_DIG *see below*#define DBL_DECIMAL_DIG *see below*#define LDBL_DECIMAL_DIG *see below*#define FLT_DIG *see below*#define DBL_DIG *see below*#define LDBL_DIG *see below*#define FLT_MIN_EXP *see below*#define DBL_MIN_EXP *see below*#define LDBL_MIN_EXP *see below*#define FLT_MIN_10_EXP *see below*#define DBL_MIN_10_EXP *see below*#define LDBL_MIN_10_EXP *see below*#define FLT_MAX_EXP *see below*#define DBL_MAX_EXP *see below*#define LDBL_MAX_EXP *see below*#define FLT_MAX_10_EXP *see below*#define DBL_MAX_10_EXP *see below*#define LDBL_MAX_10_EXP *see below*#define FLT_MAX *see below*#define DBL_MAX *see below*#define LDBL_MAX *see below*#define FLT_EPSILON *see below*#define DBL_EPSILON *see below*#define LDBL_EPSILON *see below*#define FLT_MIN *see below*#define DBL_MIN *see below*#define LDBL_MIN *see below*#define FLT_TRUE_MIN *see below*#define DBL_TRUE_MIN *see below*#define LDBL_TRUE_MIN *see below*

[1](#cfloat.syn-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L1870)

The header [<cfloat>](#header:%3ccfloat%3e "17.3.7 Header <cfloat> synopsis [cfloat.syn]") defines all macros the same as
the C standard library header [<float.h>](support.c.headers.general#header:%3cfloat.h%3e "17.15.1 General [support.c.headers.general]")[.](#cfloat.syn-1.sentence-1)

See also: ISO/IEC 9899:2024, 5.2.4.2.2