Re: [boost] [contract] toward N3351 concepts

Subject: Re: [boost] [contract] toward N3351 concepts
From: Andrzej Krzemienski (akrzemi1_at_[hidden])
Date: 2012-09-26 17:38:47

>
> Was checking expressions the only reason they were introduced in the first
> place?
>

There were more reasons:

1. The axioms have been with concepts since the inception of concepts.
Wherever you see concept StrictWeakOrder defined it is accompained by
axioms in this or other form. See for instance:
http://www.sgi.com/tech/stl/StrictWeakOrdering.html (section "Invariants").
In this sense axioms try to standardize the existing practise (and are
somewhat similar to contract-programming invariants

2. They (would) provide a standardised description of certain properties of
the code that could be used by tools for code analysis or generation. For
instance tools could auto-generate unit tests. Or certain optimizations
could be performed based on the knowledge contained in axioms.

Regards,
&rzej