Function FastPath

rapidjson/internal/strtod.h:26–33

namespace internal {

inline double FastPath(double significand, int exp) {
    if (exp < -308)
        return 0.0;
    else if (exp >= 0)
        return significand * internal::Pow10(exp);
    else
        return significand / internal::Pow10(-exp);
}

inline double StrtodNormalPrecision(double d, int p) {
    if (p < -308) {