20 General utilities library [utilities]

20.19 Primitive numeric conversions [charconv]

20.19.1 Header <charconv> synopsis [charconv.syn]

namespace std {
  // floating-point format for primitive numerical conversion
  enum class chars_­format {
    scientific = unspecified,
    fixed = unspecified,
    hex = unspecified,
    general = fixed | scientific
  };


  // [charconv.to.chars], primitive numerical output conversion
  struct to_chars_result {
    char* ptr;
    errc ec;
    friend bool operator==(const to_chars_result&, const to_chars_result&) = default;
  };

  to_chars_result to_chars(char* first, char* last, see below value, int base = 10);
  to_chars_result to_chars(char* first, char* last, bool value, int base = 10) = delete;

  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);


  // [charconv.from.chars], primitive numerical input conversion
  struct from_chars_result {
    const char* ptr;
    errc ec;
    friend bool operator==(const from_chars_result&, const from_chars_result&) = default;
  };

  from_chars_result from_chars(const char* first, const char* last,
                               see below& 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);
}