标准库标头 <charconv>

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此头文件是strings library.

指定 std::to_charsstd::from_chars 所用的格式
(枚举)
std::from_chars 的返回类型
(类)
std::to_chars 的返回类型
(类)

函数

转换字符序列到整数或浮点值
(函数)
(C++17)
转换整数或浮点值为字符序列
(函数)

概要

namespace std {
  // 初等数值转换的浮点格式
  enum class chars_format {
    scientific = /* 未指定 */,
    fixed = /* 未指定 */,
    hex = /* 未指定 */,
    general = fixed | scientific
  };
 
 
  // 初等数值输出转换
  struct to_chars_result { // 独立
    char* ptr;
    errc ec;
    friend bool operator==(const to_chars_result&, const to_chars_result&) = default;
    constexpr explicit operator bool() const noexcept { return ec == errc{}; }
  };
 
  to_chars_result to_chars(char* first, char* last, // 独立
                           /* integer-type */ value, int base = 10);
  to_chars_result to_chars(char* first, char* last, // 独立
                           bool value, int base = 10) = delete;
  to_chars_result to_chars(char* first, char* last, // 独立
                           /* floating-point-type */ value);
  to_chars_result to_chars(char* first, char* last, // 独立
                           /* floating-point-type */ value, chars_format fmt);
  to_chars_result to_chars(char* first, char* last, // 独立
                           /* floating-point-type */ value,
                           chars_format fmt, int precision);
 
  // 初等数值输入转换
  struct from_chars_result { // 独立
    const char* ptr;
    errc ec;
    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, // 独立
                               const char* last, /* integer-type */& value,
                               int base = 10);
  from_chars_result from_chars(const char* first, // 独立或被删除
                               const char* last, /* floating-point-type */& value,
                               chars_format fmt = chars_format::general);
}