Geek asks and answers

Logging Macro Recording

im writing the logging class at the moment. Logger works with streams and also prints the object that is currently being written. Here is the macro:

#define OBJLOG(DL, what) DL <= this->Logger->getDebugLevel() ? *this->Logger << DL << "[" << this->Name << "]: "<< what << std::endl : this->Logger->doNothing();

Pseudocode Varient for a better overview:

#define OBJLOG(debuglevel, what) debuglevel <= logger.debuglevel ? logger.log(what) : logger.doNothing()

Is there a way around the doNothing call, how to do nothing at all? Thanks in advance.

+3
source share
3 answers
#define OBJLOG(DL, what) do { if(DL <= this->Logger->getDebugLevel()) *this->Logger << DL << "[" << this->Name << "]: "<< what << std::endl; } while(0)

See Why use explanations for the seemingly pointless do-while and if-else statements in macros? . ( do {} while(0)This is not strictly necessary here, but I would rather not leak out ostream.)

In addition, the use of macro arguments should always be used in parentheses, for example:

#define OBJLOG(DL, what) do { if((DL) <= this->Logger->getDebugLevel()) *this->Logger << (DL) << "[" << this->Name << "]: "<< (what) << std::endl; } while(0)

, ( ), .

+4

  • logger.log() .

  • : debuglevel <= logger.debuglevel && & & Logger.log

.

+1

If you need an expression that does nothing, try it (void)0.

0
source

More articles:


All Articles