Function SafeLog

include/LightGBM/utils/common.h:914–920

template <typename T>
static T SafeLog(T x) {
  if (x > 0) {
    return std::log(x);
  } else {
    return -INFINITY;
  }
}

inline bool CheckASCII(const std::string& s) {
  for (auto c : s) {