| title | <charconv> | |
|---|---|---|
| ms.date | 07/22/2020 | |
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Quickly convert a character sequence to an integer or floating-point value, and the other way around. Use to write and roundtrip floating point values in JSON and text files.
The conversion functions are tuned for performance, and also support shortest-round-trip behavior. Shortest-round-trip behavior means when a number is converted to chars, only enough precision is written out to enable recovering the original number when converting those chars back to a floating-point. No other CRT or STL function provides this capability.
Some of the benefits of using the <charconv> library are:
- The sequence of chars representing a numeric value doesn't need to be null-terminated. Likewise, when a number is converted to chars, the result isn't null-terminated.
- Conversion functions don't allocate memory. You own the buffer in all cases.
- Conversion functions don't throw. They return a structure that contains error information.
- Conversions aren't runtime rounding-mode sensitive.
- Conversions aren't locale aware. They always print and parse decimal points as '.', never as ',' for locales that use commas.
Header: <charconv>
Namespace: std
/std:c++17, or later, is required.
| Type | Description |
|---|---|
| chars_format | Specifies formatting type such as scientific, hex, and so on. |
| from_chars_result | Holds the result of a from_chars conversion. |
| to_chars_result | Holds the result of a to_chars conversion. |
| Function | Description |
|---|---|
| from_chars | Convert chars to an integer, float, or double. |
| to_chars | Convert an integer, float, or double to chars. |