[charconv.syn]

# 28 Text processing library [[text]](./#text)

## 28.2 Primitive numeric conversions [[charconv]](charconv#syn)

### 28.2.1 Header <charconv> synopsis [charconv.syn]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L24)

When a function is specified
with a type placeholder of *integer-type*,
the implementation provides overloads
for char and all cv-unqualified signed and unsigned integer types
in lieu of *integer-type*[.](#1.sentence-1)

When a function is specified
with a type placeholder of *floating-point-type*,
the implementation provides overloads
for all cv-unqualified floating-point types ([[basic.fundamental]](basic.fundamental "6.9.2 Fundamental types"))
in lieu of *floating-point-type*[.](#1.sentence-2)

[🔗](#header:%3ccharconv%3e)

namespace std {// floating-point format for primitive numerical conversionenum class [chars_format](#lib:chars_format "28.2.1 Header <charconv> synopsis [charconv.syn]") {[scientific](#lib:chars_format,scientific "28.2.1 Header <charconv> synopsis [charconv.syn]") = *unspecified*, [fixed](#lib:chars_format,fixed "28.2.1 Header <charconv> synopsis [charconv.syn]") = *unspecified*, [hex](#lib:chars_format,hex "28.2.1 Header <charconv> synopsis [charconv.syn]") = *unspecified*, [general](#lib:chars_format,general "28.2.1 Header <charconv> synopsis [charconv.syn]") = fixed | scientific }; // [[charconv.to.chars]](charconv.to.chars "28.2.2 Primitive numeric output conversion"), primitive numerical output conversionstruct [to_chars_result](#lib:to_chars_result "28.2.1 Header <charconv> synopsis [charconv.syn]") { // freestandingchar* [ptr](#lib:to_chars_result,ptr "28.2.1 Header <charconv> synopsis [charconv.syn]");
 errc [ec](#lib:to_chars_result,ec "28.2.1 Header <charconv> synopsis [charconv.syn]"); friend bool operator==(const to_chars_result&, const to_chars_result&) = default; constexpr explicit operator bool() const noexcept { return ec == errc{}; }}; constexpr to_chars_result to_chars(char* first, char* last, // freestanding*integer-type* value, int base = 10);
 to_chars_result to_chars(char* first, char* last, // freestandingbool value, int base = 10) = delete;

 to_chars_result to_chars(char* first, char* last, // freestanding-deleted*floating-point-type* value);
 to_chars_result to_chars(char* first, char* last, // freestanding-deleted*floating-point-type* value, chars_format fmt);
 to_chars_result to_chars(char* first, char* last, // freestanding-deleted*floating-point-type* value, chars_format fmt, int precision); // [[charconv.from.chars]](charconv.from.chars "28.2.3 Primitive numeric input conversion"), primitive numerical input conversionstruct [from_chars_result](#lib:from_chars_result "28.2.1 Header <charconv> synopsis [charconv.syn]") { // freestandingconst char* [ptr](#lib:from_chars_result,ptr "28.2.1 Header <charconv> synopsis [charconv.syn]");
 errc [ec](#lib:from_chars_result,ec "28.2.1 Header <charconv> synopsis [charconv.syn]"); friend bool operator==(const from_chars_result&, const from_chars_result&) = default; constexpr explicit operator bool() const noexcept { return ec == errc{}; }}; constexpr from_chars_result from_chars(const char* first, const char* last, // freestanding*integer-type*& value, int base = 10);

 from_chars_result from_chars(const char* first, const char* last, // freestanding-deleted*floating-point-type*& value,
 chars_format fmt = chars_format::general);}

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L84)

The type chars_format is a bitmask type ([[bitmask.types]](bitmask.types "16.3.3.3.3 Bitmask types"))
with elements scientific, fixed, and hex[.](#2.sentence-1)

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L88)

The types to_chars_result and from_chars_result have the data members and special members specified above[.](#3.sentence-1)

They have no base classes or members other than those specified[.](#3.sentence-2)