Method CheckOpString

chromium/base/logging.h:426–426

// true iff the pointer is NULL.
struct CheckOpString {
  CheckOpString(string* str) : str_(str) { }
  // No destructor: if str_ is non-NULL, we're about to LOG(FATAL),
  // so there's no point in cleaning up str_.
  operator bool() const { return PREDICT_FALSE(str_ != NULL); }