[simd.loadstore]

# 29 Numerics library [[numerics]](./#numerics)

## 29.10 Data-parallel types [[simd]](simd#loadstore)

### 29.10.8 basic_vec non-member operations [[simd.nonmembers]](simd.nonmembers#simd.loadstore)

#### 29.10.8.6 basic_vec load and store functions [simd.loadstore]

[🔗](#lib:unchecked_load,simd)

`template<class V = see below, ranges::[contiguous_range](range.refinements#concept:contiguous_range "25.4.6 Other range refinements [range.refinements]") R, class... Flags>
  requires ranges::[sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]")<R>
  constexpr V unchecked_load(R&& r, flags<Flags...> f = {});
template<class V = see below, ranges::[contiguous_range](range.refinements#concept:contiguous_range "25.4.6 Other range refinements [range.refinements]") R, class... Flags>
  requires ranges::[sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]")<R>
  constexpr V unchecked_load(R&& r, const typename V::mask_type& mask, flags<Flags...> f = {});
template<class V = see below, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, class... Flags>
  constexpr V unchecked_load(I first, iter_difference_t<I> n, flags<Flags...> f = {});
template<class V = see below, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, class... Flags>
  constexpr V unchecked_load(I first, iter_difference_t<I> n, const typename V::mask_type& mask,
                             flags<Flags...> f = {});
template<class V = see below, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<I> S, class... Flags>
  constexpr V unchecked_load(I first, S last, flags<Flags...> f = {});
template<class V = see below, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<I> S, class... Flags>
  constexpr V unchecked_load(I first, S last, const typename V::mask_type& mask,
                             flags<Flags...> f = {});
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18486)

Let

- [(1.1)](#1.1)

mask be V​::​mask_type(true) for the overloads with no mask parameter;

- [(1.2)](#1.2)

R be span<const iter_value_t<I>> for the overloads with no
 template parameter R;

- [(1.3)](#1.3)

r be R(first, n) for the overloads with an n parameter and R(first, last) for the overloads with a last parameter[.](#1.sentence-1)

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18501)

*Mandates*: If ranges​::​size(r) is a constant expression thenranges​::​size(r)  ≥  V​::​size()[.](#2.sentence-1)

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18506)

*Preconditions*: 

- [(3.1)](#3.1)

  [first, first + n) is a valid range for the overloads with an n parameter[.](#3.1.sentence-1)

- [(3.2)](#3.2)

  [first, last) is a valid range for the overloads with a last parameter[.](#3.2.sentence-1)

- [(3.3)](#3.3)

  ranges​::​size(r)  ≥  V​::​size()

[4](#4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18516)

*Effects*: Equivalent to: return partial_load<V>(r, mask, f);

[5](#5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18520)

*Remarks*: The default argument for template parameter V isbasic_vec<ranges​::​range_value_t<R>>[.](#5.sentence-1)

[🔗](#lib:partial_load,simd)

`template<class V = see below, ranges::[contiguous_range](range.refinements#concept:contiguous_range "25.4.6 Other range refinements [range.refinements]") R, class... Flags>
  requires ranges::[sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]")<R>
  constexpr V partial_load(R&& r, flags<Flags...> f = {});
template<class V = see below, ranges::[contiguous_range](range.refinements#concept:contiguous_range "25.4.6 Other range refinements [range.refinements]") R, class... Flags>
  requires ranges::[sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]")<R>
  constexpr V partial_load(R&& r, const typename V::mask_type& mask, flags<Flags...> f = {});
template<class V = see below, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, class... Flags>
  constexpr V partial_load(I first, iter_difference_t<I> n, flags<Flags...> f = {});
template<class V = see below, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, class... Flags>
  constexpr V partial_load(I first, iter_difference_t<I> n, const typename V::mask_type& mask,
                           flags<Flags...> f = {});
template<class V = see below, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<I> S, class... Flags>
  constexpr V partial_load(I first, S last, flags<Flags...> f = {});
template<class V = see below, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<I> S, class... Flags>
  constexpr V partial_load(I first, S last, const typename V::mask_type& mask,
                           flags<Flags...> f = {});
`

[6](#6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18547)

Let

- [(6.1)](#6.1)

mask be V​::​mask_type(true) for the overloads with no mask parameter;

- [(6.2)](#6.2)

R be span<const iter_value_t<I>> for the overloads with no
 template parameter R;

- [(6.3)](#6.3)

r be R(first, n) for the overloads with an n parameter and R(first, last) for the overloads with a last parameter[.](#6.sentence-1)

[7](#7)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18562)

*Mandates*: 

- [(7.1)](#7.1)

ranges​::​range_value_t<R> is a vectorizable type,

- [(7.2)](#7.2)

same_as<remove_cvref_t<V>, V> is true,

- [(7.3)](#7.3)

V is an enabled specialization of basic_vec, and

- [(7.4)](#7.4)

if the template parameter pack Flags does not contain *convert-flag*, then the conversion from ranges​::​range_value_t<R> to V​::​value_type is
 value-preserving[.](#7.sentence-1)

[8](#8)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18578)

*Preconditions*: 

- [(8.1)](#8.1)

  [first, first + n) is a valid range for the overloads with an n parameter[.](#8.1.sentence-1)

- [(8.2)](#8.2)

  [first, last) is a valid range for the overloads with a last parameter[.](#8.2.sentence-1)

- [(8.3)](#8.3)

  If the template parameter pack Flags contains *aligned-flag*, ranges​::​data(r) points to storage
 aligned by alignment_v<V, ranges​::​range_value_t<R>>[.](#8.3.sentence-1)

- [(8.4)](#8.4)

  If the template parameter pack Flags contains *overaligned-flag*<N>, ranges​::​data(r) points to
 storage aligned by N[.](#8.4.sentence-1)

[9](#9)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18597)

*Effects*: Initializes the ith element with  

mask[i] && i < ranges​::​size(r) ?static_cast<T>(​ranges​::​data(r)[i]) : T() for all i in the range of
[0, V​::​size())[.](#9.sentence-2)

[10](#10)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18604)

*Remarks*: The default argument for template parameter V isbasic_vec<ranges​::​range_value_t<R>>[.](#10.sentence-1)

[🔗](#lib:unchecked_store,simd)

`template<class T, class Abi, ranges::[contiguous_range](range.refinements#concept:contiguous_range "25.4.6 Other range refinements [range.refinements]") R, class... Flags>
  requires ranges::[sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]")<R> && [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<ranges::iterator_t<R>, T>
  constexpr void unchecked_store(const basic_vec<T, Abi>& v, R&& r, flags<Flags...> f = {});
template<class T, class Abi, ranges::[contiguous_range](range.refinements#concept:contiguous_range "25.4.6 Other range refinements [range.refinements]") R, class... Flags>
  requires ranges::[sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]")<R> && [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<ranges::iterator_t<R>, T>
  constexpr void unchecked_store(const basic_vec<T, Abi>& v, R&& r,
    const typename basic_vec<T, Abi>::mask_type& mask, flags<Flags...> f = {});
template<class T, class Abi, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, class... Flags>
  requires [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<I, T>
  constexpr void unchecked_store(const basic_vec<T, Abi>& v, I first, iter_difference_t<I> n,
                                 flags<Flags...> f = {});
template<class T, class Abi, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, class... Flags>
  requires [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<I, T>
  constexpr void unchecked_store(const basic_vec<T, Abi>& v, I first, iter_difference_t<I> n,
    const typename basic_vec<T, Abi>::mask_type& mask, flags<Flags...> f = {});
template<class T, class Abi, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<I> S, class... Flags>
  requires [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<I, T>
  constexpr void unchecked_store(const basic_vec<T, Abi>& v, I first, S last,
                                 flags<Flags...> f = {});
template<class T, class Abi, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<I> S, class... Flags>
  requires [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<I, T>
  constexpr void unchecked_store(const basic_vec<T, Abi>& v, I first, S last,
    const typename basic_vec<T, Abi>::mask_type& mask, flags<Flags...> f = {});
`

[11](#11)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18638)

Let

- [(11.1)](#11.1)

mask be basic_vec<T, Abi>​::​mask_type(true) for the
 overloads with no mask parameter;

- [(11.2)](#11.2)

R be span<iter_value_t<I>> for the overloads with no
 template parameter R;

- [(11.3)](#11.3)

r be R(first, n) for the overloads with an n parameter and R(first, last) for the overloads with a last parameter[.](#11.sentence-1)

[12](#12)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18653)

*Mandates*: If ranges​::​size(r) is a constant expression thenranges​::​size(r)  ≥  *simd-size-v*<T, Abi>[.](#12.sentence-1)

[13](#13)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18658)

*Preconditions*: 

- [(13.1)](#13.1)

  [first, first + n) is a valid range for the overloads with an n parameter[.](#13.1.sentence-1)

- [(13.2)](#13.2)

  [first, last) is a valid range for the overloads with a last parameter[.](#13.2.sentence-1)

- [(13.3)](#13.3)

  ranges​::​size(r)  ≥  *simd-size-v*<T, Abi>

[14](#14)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18671)

*Effects*: Equivalent to: partial_store(v, r, mask, f)[.](#14.sentence-1)

[🔗](#lib:partial_store,simd)

`template<class T, class Abi, ranges::[contiguous_range](range.refinements#concept:contiguous_range "25.4.6 Other range refinements [range.refinements]") R, class... Flags>
  requires ranges::[sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]")<R> && [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<ranges::iterator_t<R>, T>
  constexpr void partial_store(const basic_vec<T, Abi>& v, R&& r, flags<Flags...> f = {});
template<class T, class Abi, ranges::[contiguous_range](range.refinements#concept:contiguous_range "25.4.6 Other range refinements [range.refinements]") R, class... Flags>
  requires ranges::[sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]")<R> && [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<ranges::iterator_t<R>, T>
  constexpr void partial_store(const basic_vec<T, Abi>& v, R&& r,
    const typename basic_vec<T, Abi>::mask_type& mask, flags<Flags...> f = {});
template<class T, class Abi, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, class... Flags>
  requires [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<I, T>
  constexpr void partial_store(const basic_vec<T, Abi>& v, I first, iter_difference_t<I> n,
                               flags<Flags...> f = {});
template<class T, class Abi, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, class... Flags>
  requires [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<I, T>
  constexpr void partial_store(const basic_vec<T, Abi>& v, I first, iter_difference_t<I> n,
    const typename basic_vec<T, Abi>::mask_type& mask, flags<Flags...> f = {});
template<class T, class Abi, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<I> S, class... Flags>
  requires [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<I, T>
  constexpr void partial_store(const basic_vec<T, Abi>& v, I first, S last,
                               flags<Flags...> f = {});
template<class T, class Abi, [contiguous_iterator](iterator.concept.contiguous#concept:contiguous_iterator "24.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]") I, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<I> S, class... Flags>
  requires [indirectly_writable](iterator.concept.writable#concept:indirectly_writable "24.3.4.3 Concept indirectly_­writable [iterator.concept.writable]")<I, T>
  constexpr void partial_store(const basic_vec<T, Abi>& v, I first, S last,
    const typename basic_vec<T, Abi>::mask_type& mask, flags<Flags...> f = {});
`

[15](#15)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18704)

Let

- [(15.1)](#15.1)

mask be basic_vec<T, Abi>​::​mask_type(true) for the
 overloads with no mask parameter;

- [(15.2)](#15.2)

R be span<iter_value_t<I>> for the overloads with no
 template parameter R;

- [(15.3)](#15.3)

r be R(first, n) for the overloads with an n parameter and R(first, last) for the overloads with a last parameter[.](#15.sentence-1)

[16](#16)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18719)

*Mandates*: 

- [(16.1)](#16.1)

ranges​::​range_value_t<R> is a vectorizable type, and

- [(16.2)](#16.2)

if the template parameter pack Flags does not contain *convert-flag*, then the conversion from T to ranges​::​range_value_t<R> is value-preserving[.](#16.sentence-1)

[17](#17)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18730)

*Preconditions*: 

- [(17.1)](#17.1)

  [first, first + n) is a valid range for the overloads with an n parameter[.](#17.1.sentence-1)

- [(17.2)](#17.2)

  [first, last) is a valid range for the overloads with a last parameter[.](#17.2.sentence-1)

- [(17.3)](#17.3)

  If the template parameter pack Flags contains *aligned-flag*, ranges​::​data(r) points to storage
 aligned by alignment_v<basic_vec<T, Abi>,
 ranges​::​range_value_t<R>>[.](#17.3.sentence-1)

- [(17.4)](#17.4)

  If the template parameter pack Flags contains *overaligned-flag*<N>, ranges​::​data(r) points to
 storage aligned by N[.](#17.4.sentence-1)

[18](#18)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L18750)

*Effects*: For all i in the range of [0, basic_vec<T, Abi>​::​size()), ifmask[i] && i < ranges​::​​size(r) is true, evaluatesranges​::​data(r)[i] = v[i][.](#18.sentence-1)