Re: [Boost-users] Metaprogramming Question

Subject: Re: [Boost-users] Metaprogramming Question
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2012-02-09 01:21:59

On Thu, 9 Feb 2012, John M. Dlugosz wrote:

> I've not had much opportunity to do much template metaprogramming in my work, 
> but I've kept up with my reading.  So, might I get some advice on how to 
> approach this problem?
>
> I'm thinking of an assert-like statement that follows the syntax of 
> Boost.Format, thus avoiding the variadic argument list.
>
>    MY_FANCY_ASSERT (cond, "format string") % arg % arg;
>
> works if the macro expands to an unnamed temporary, whose destructor does the 
> interesting work if the first argument is false.

Would it be reasonable for your use case to have MY_FANCY_ASSERT be:

#define MY_FANCY_ASSERT(cond, str) \
   if (cond) {} else format(str) % __FILE__ % __LINE__

or similar?  It would restrict where you could use it, but would be simple 
and guarantee the properties you want.

-- Jeremiah Willcock