[boost] Re: [string algo review] exception specification

From: David Abrahams (dave_at_[hidden])
Date: 2003-10-24 12:20:44

Pavol Droba <droba_at_[hidden]> writes:

> An example: generic trim algorithm.
>
> <example>
>
> a) variant 1:
> 	template<typename OutputIteratorT, typename InputContainerT, typename PredicateT> 
> 	OutputIteratorT trim_copy(
> 		OutputIteratorT Output, 
> 		const InputContainerT & Input, 
>       PredicateT IsSpace);
>
> -Basic exception guarantie of this algorithm is give iff following operations
>  give this guarantie:
>
>   InputContainerT::const_iterator::operator++
>                                  ::operator*
...

You can eliminate most of this mess by giving the requirement that
all operations give the basic guarantee.  In fact, you don't actually
need to say it: if an operation doesn't preserve invariants, well,
then, they weren't invariants to begin with, were they?  That's what
the C++ standard does.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com