Standard library header <charconv>

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Standard Library headers

Language Support
<cstddef> <limits> <climits> <coroutine>	<cfloat> <cstdint> <new> <source_location>	<typeinfo> <exception> <initializer_list> <version>	<csignal> <csetjmp> <cstdarg>
Concepts
<concepts>
Diagnostics
<stdexcept>	<cassert>	<cerrno>	<system_error>
General utilities
<utility> <memory> <memory_resource> <scoped_allocator>     <compare>	<bitset> <tuple> <optional> <any> <variant>	<type_traits> <ratio> <chrono> <typeindex> <functional>	<ctime> <cstdlib>
Strings
<string> <string_view> <cstring>	<charconv> <format>	<cctype> <cwctype>	<cwchar> <cuchar>
Localization
<locale>	<codecvt>	<clocale>
Containers
<span> <array> <vector>	<deque> <forward_list> <list>	<map> <set> <queue>	<unordered_map> <unordered_set> <stack>
Iterators
<iterator>
Ranges
<ranges>
Algorithms
<algorithm>	<execution>
Numerics
<complex> <random>	<valarray> <numeric>	<bit> <numbers>	<cfenv> <cmath>
Input/Output
<iosfwd> <ios> <iomanip> <streambuf>	<istream> <ostream> <iostream>	<sstream> <fstream> <syncstream>	<cstdio> <cinttypes> <strstream>
Regular expressions
<regex>
Filesystem support
<filesystem>
Thread support
<thread> <atomic> <mutex>	<shared_mutex> <condition_variable> <future>	<stop_token> <semaphore>	<latch> <barrier>
C compatibility
<ciso646> <cstdalign>	<cstdbool> <ccomplex>	<ctgmath>

 

Classes

chars_format (C++17)

specifies formatting for std::to_chars and std::from_chars (enum)

Functions

from_chars (C++17)	converts a character sequence to an integer or floating-point value (function)
to_chars (C++17)	converts an integer or floating-point value to a character sequence (function)

Synopsis

namespace std {
    // floating-point format for primitive numerical conversion
    enum class chars_format {
        scientific = /*unspecified*/ ,
        fixed = /*unspecified*/ ,
        hex = /*unspecified*/ ,
        general = fixed | scientific
    };
    // primitive numerical output conversion
    struct to_chars_result {
        char* ptr;
        errc ec;
    };
    to_chars_result to_chars(char* first, char* last,
                             /*see description*/ value, int base = 10);
    to_chars_result to_chars(char* first, char* last, float value);
    to_chars_result to_chars(char* first, char* last, double value);
    to_chars_result to_chars(char* first, char* last, long double value);
    to_chars_result to_chars(char* first, char* last, float value,
                             chars_format fmt);
    to_chars_result to_chars(char* first, char* last, double value, 
                             chars_format fmt);
    to_chars_result to_chars(char* first, char* last, long double value,
                             chars_format fmt);
    to_chars_result to_chars(char* first, char* last, float value,
                             chars_format fmt, int precision);
    to_chars_result to_chars(char* first, char* last, double value,
                             chars_format fmt, int precision);
    to_chars_result to_chars(char* first, char* last, long double value,
                             chars_format fmt, int precision);
    // primitive numerical input conversion
    struct from_chars_result {
        const char* ptr;
        errc ec;
    };
    from_chars_result from_chars(const char* first, const char* last,
                                 /*see description*/ & value, int base = 10);
    from_chars_result from_chars(const char* first, const char* last, float& value,
                                 chars_format fmt = chars_format::general);
    from_chars_result from_chars(const char* first, const char* last, double& value,
                                 chars_format fmt = chars_format::general);
    from_chars_result from_chars(const char* first, const char* last, long double& value,
                                 chars_format fmt = chars_format::general);
}