chars_format enum
Used with the <charconv> library to specify the floating-point format for primitive numerical conversions.
Syntax
enum class chars_format {
scientific = unspecified,
fixed = unspecified,
hex = unspecified,
general = fixed | scientific
};
Members
Element | Description |
---|---|
scientific |
Causes from_chars() to expect and parse an exponent. It is like the printf() format specifier 'e' , which formats for scientific notation, like "1.729e+01" . |
fixed |
Causes from_chars() not to expect or parse an exponent. It is like the printf() format specifier 'f' , which formats for floating-point, like "17.29" . |
hex |
Causes from_chars() to expect the number in hexadecimal format, but without a leading 0x . |
general |
Causes from_chars() to accept (but not require) an exponent. For to_chars() , it is like the printf() format specifier 'g' , which switches between scientific notation or fixed. It takes into consideration what the exponent will be so that it can generate reasonably compact output. For example: 1e-5 results in "1e-05" , but 1e-4 results in "0.001" . 1e5 results in 100000 , while 1e6 results in 1e+06 . 1e0 produces 1 . |
Remarks
For the from_chars functions, this enum describes what kind of input to expect. For the to_chars functions, it describes what kind of output to emit.
Requirements
Header: <charconv>
Namespace: std
/std:c++17
or later is required.