Method CheckOpString

include/singa/utils/logging.h:143–143

// true iff the pointer is non-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 str_ != NULL; }