Re: [boost] Re: recommend logging library?

From: Patrick Bennett (patrick.bennett_at_[hidden])
Date: 2004-03-18 22:19:20

Darren Cook wrote:

> The problem comes when I have a function that takes an ostream; then I 
> have to expose the internals:
>
>     LOG("Here is data:");LOG(obj->debug_info(*logfile,true,false));
>
> Is there a better way?
>
Yes,
#define SOME_LOG_MACRO( MiscParams) \
        if ( ! ShouldLog( MiscParams) )  \
        { /* Don't execute, or log anything */ \
        } \
        else /* create something that returns an ostream& derived 
instance */ (MiscParams).GetStream ()

You can then use:
SOME_LOG_MACRO( xxx)  << "foo:" << foo << " bar:" << bar;
and it will only execute the << methods if logging is enabled, or if 
it's necessary based on whatever you define.  Plus, the streamed data 
doesn't have to be included in the macro as a parameter.

Cheers...