Re: [boost] [guidelines] why template errors suck

Subject: Re: [boost] [guidelines] why template errors suck
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2010-09-26 08:51:34

Jeremy Maitin-Shepard a écrit :
> Obviously actual timing data would be useful, but it seems that in some 
> cases these techniques might result in increased compilation time, which 
> is at least as serious a problem as the error messages.

Indeed.

The idea, in order to provide better error messages, is to test whether 
all the expressions you're going to evaluate are going to lead to errors.

Then, if they don't, you evaluate said expressions. However, this 
basically ends up doing the same thing twice (or worse, checking the 
expressions are valid may be more costly than actually instanciating 
them) as far as the compiler is concerned.

Therefore I think the solution is to provide a compiler debug mode in 
which we do this testing, and one where we don't.