strtof
float strtof(const char *__restrict, char **__restrict);
extern float strtof ANSI((CONST char *, char **));
strtof(CONST char *s, char **sp)
DEF_STRONG(strtof);
PROTO_NORMAL(strtof);
#define STRTOD_FUNC strtof
float res = strtof(buf, (char **)NULL);
f = strtof(buf, &end);
af[1] = strtof(nan_str, &end);
af[3] = strtof("nan", NULL);