llog

##introduction

• a small logger support stdout ,file record, and may network later
• written by C++11

##usage ###logging

#include "llog.h"
LOG(INFO) << "lllog";
LOG_IF(VERBOSE, 1 > 0) << "expression log";

###configuration

• default set to STDOUT, you can switch to STDERR by set

  ins::log_to_stderr = true;

• support dup log to file, and set log level

  auto &config = ins::Configuration::GetInstance();
  config.Configure(ins::Configuration::LOG_FILE, "/tmp/test.log");
  config.Configure(ins::Configuration::LOG_LEVEL, "ERROR");

###CHECK Macro

• used to replace assert. when expression equal false, CHECK will print msg and exit program.

  CHECK(1==1) << "1 != 1";