Function to_float

ext/include/llvm/ADT/StringExtras.h:199–208

namespace detail {
template <typename N>
inline bool to_float(const Twine &T, N &Num, N (*StrTo)(const char *, char **)) {
  SmallString<32> Storage;
  StringRef S = T.toNullTerminatedStringRef(Storage);
  char *End;
  N Temp = StrTo(S.data(), &End);
  if (*End != '\0')
    return false;
  Num = Temp;
  return true;
}
}

inline bool to_float(const Twine &T, float &Num) {