[boost] Re: assert() replacement?

From: Valentin Bonnard (Bonnard.V_at_[hidden])
Date: 1999-09-01 06:08:00

Greg Colvin wrote:
> 
> From: Valentin Bonnard <Bonnard.V_at_[hidden]>
> > Kevlin Henney wrote:
> >
> > > Valentin Bonnard wrote:
> > > [...]
> > > >    For boost library authors, the first need is perhaps not as great as
> > > >    that for a user dotting their own code w/ assertions. Naming and
> > > >    describing what constraint was violated is often more useful to a
> > > >    library user than receiving a mysterious message about a piece of code
> > > >    they have nothing to do w/!
> > >
> > > This can easilly be done with a comment:
> > >
> > > // must fobnicate before we tweak
> > > assert (x ? t(3) : 3434==i+j);
> > >
> > >    And there was me thinking that the compiler ignored comments ;-)
> > >
> > >    If you wish to do this 'properly' w/ assert:
> > >
> > >      assert (("must fobnicate before we tweak", x ? t(3) : 3434==i+j));
> >
> > Then the string will take space in the program (I have read
> > that it was a problem for big apps).
> 
> Unless the translator removes duplicate string literals?

I have read this assertion (oops, sorry) in a book about 
C, so inline functions weren't a problem, written by someone 
from MS.

Anyway, I think that it's cleaner to send explanations 
to STDERR than the expression used in the assertion, 
which doesn't make much sens w/o its context (what is 
x, i, j ? you may ask).

> > I would rather add an argument to assertion:
> >
> >   assertion ("must fobnicate before we tweak", x ? t(3) : 3434==i+j);
> 
> How does this use less space?

If you use an empty string it does use less code space.
Otherwise it doesn't.

I sent the reply about code space just because I forgot 
the #cond in the macro definition and I didn't wanted to 
admit that.

> Anyway, I prefer the string to be an optional second argument:
>     assertion (x ? t(3) : 3434==i+j, "must fobnicate before we tweak");

Good idea

-- 
Valentin Bonnard