strtold
strtold(const char * __restrict, char ** __restrict);
#define lua_str2number(s,p) strtold((s), (p))
ld = strtold(buf, &end);
ald[3] = strtold("nan", NULL);
ald[1] = strtold(nan_str, &end);
#define lua_str2number(s,p) strtold((s), (p))
*dp = strtold(*gargv, &ep);