redis/deps/fast_float/fast_float_strtod.cpp

33 lines
1.3 KiB
C++

#include "fast_float.h"
#include <iostream>
#include <string>
#include <system_error>
#include <cerrno>
/* Convert NPTR to a double using the fast_float library.
*
* This function behaves similarly to the standard strtod function, converting
* the initial portion of the string pointed to by `nptr` to a `double` value,
* using the fast_float library for high performance. If the conversion fails,
* errno is set to EINVAL error code.
*
* @param nptr A pointer to the null-terminated byte string to be interpreted.
* @param endptr A pointer to a pointer to character. If `endptr` is not NULL,
* it will point to the character after the last character used
* in the conversion.
* @return The converted value as a double. If no valid conversion could
* be performed, returns 0.0.
* If ENDPTR is not NULL, a pointer to the character after the last one used
* in the number is put in *ENDPTR. */
extern "C" double fast_float_strtod(const char *nptr, char **endptr) {
double result = 0.0;
auto answer = fast_float::from_chars(nptr, nptr + strlen(nptr), result);
if (answer.ec != std::errc()) {
errno = EINVAL; // Fallback to for other errors
}
if (endptr != NULL) {
*endptr = (char *)answer.ptr;
}
return result;
}