C++ Simple Message/Logging Class

enum LogLevel {
  LOGLEVEL_INFO,     // Informational.  This is never actually used by
                     // libprotobuf.
  LOGLEVEL_WARNING,  // Warns about issues that, although not technically a
                     // problem now, could cause problems in the future.  For
                     // example, a // warning will be printed when parsing a
                     // message that is near the message size limit.
  LOGLEVEL_ERROR,    // An error occurred which should never happen during
                     // normal use.
  LOGLEVEL_FATAL,    // An error occurred from which the library cannot
                     // recover.  This usually indicates a programming error
                     // in the code which calls the library, especially when
                     // compiled in debug mode.
};

class LIBPROTOBUF_EXPORT LogMessage {
 public:
  LogMessage(LogLevel level, const char* filename, int line);
  ~LogMessage();

  LogMessage& operator<<(const std::string& value);
  LogMessage& operator<<(const char* value);
  LogMessage& operator<<(char value);
  LogMessage& operator<<(int value);
  LogMessage& operator<<(uint value);
  LogMessage& operator<<(long value);
  LogMessage& operator<<(unsigned long value);
  LogMessage& operator<<(long long value);
  LogMessage& operator<<(unsigned long long value);
  LogMessage& operator<<(double value);
  LogMessage& operator<<(void* value);
  LogMessage& operator<<(const StringPiece& value);
  LogMessage& operator<<(const ::google::protobuf::util::Status& status);
  LogMessage& operator<<(const uint128& value);

 private:
  friend class LogFinisher;
  void Finish();

  LogLevel level_;
  const char* filename_;
  int line_;
  std::string message_;
};

1 class LIBPROTOBUF_EXPORT LogFinisher {
2  public:
3   void operator=(LogMessage& other) {
4     other.Finish();
5   }
6 };

 1 #define GOOGLE_LOG(LEVEL)                                                 \
 2   ::google::protobuf::internal::LogFinisher() =                           \
 3     ::google::protobuf::internal::LogMessage(                             \
 4       ::google::protobuf::LOGLEVEL_##LEVEL, __FILE__, __LINE__)
 5 #define GOOGLE_LOG_IF(LEVEL, CONDITION) \
 6   !(CONDITION) ? (void)0 : GOOGLE_LOG(LEVEL)
 7 
 8 #define GOOGLE_CHECK(EXPRESSION) \
 9   GOOGLE_LOG_IF(FATAL, !(EXPRESSION)) << "CHECK failed: " #EXPRESSION ": "
10 #define GOOGLE_CHECK_OK(A) GOOGLE_CHECK(::google::protobuf::internal::IsOk(A))
11 #define GOOGLE_CHECK_EQ(A, B) GOOGLE_CHECK((A) == (B))
12 #define GOOGLE_CHECK_NE(A, B) GOOGLE_CHECK((A) != (B))
13 #define GOOGLE_CHECK_LT(A, B) GOOGLE_CHECK((A) <  (B))
14 #define GOOGLE_CHECK_LE(A, B) GOOGLE_CHECK((A) <= (B))
15 #define GOOGLE_CHECK_GT(A, B) GOOGLE_CHECK((A) >  (B))
16 #define GOOGLE_CHECK_GE(A, B) GOOGLE_CHECK((A) >= (B))

1 GOOGLE_LOG(INFO)<< "Hello " <<"sunshy\n";
2 GOOGLE_CHECK_EQ(var0, var1)<<" var0 not equal var\n";