Config and "unused variables"

From: williamkempf_at_[hidden]
Date: 2001-09-24 15:30:53

It's fairly common to have unused variables in Boost code for various 
reasons.  For instance, a common work around for a VC++ bug is to 
have code such as:

template <typename T>
void foo(T* dummy=0)
{
}

The dummy parameter is never used, and is there solely to help the 
VC++ compiler figure out the template argument types.  Most compilers 
will warn on such usage and as good citizens we should try and reduce 
all possible warnings generated by any compiler.  Currently I don't 
see any mechanism for eliminating this stuff in the config files, but 
Jeremy Siek has a simple solution in concept_check.hpp:

template <class T> inline void ignore_unused_variable_warning(const 
T&) { }

I think it would be beneficial to have this in a more reusable 
fashion for all Boost libraries and think the config files would be a 
handy place for it (though I'd be fine with it in any other location 
as long as it was a small header).  I might reduce the name to just 
unused_variable(), though other's might not care for the less verbose 
name.

I currently have need of this for Boost.Threads, so... Any thoughts 
or comments on this?

Bill Kempf