Re: [boost] [test] testing for strict weak ordering

From: David Abrahams (dave_at_[hidden])
Date: 2007-02-02 10:32:59

Thorsten Ottosen <thorsten.ottosen_at_[hidden]> writes:

> Hi,
>
> I couldn't find a way to do this. Maybe I have overlooked something.
> Anyway, making sure that operator<, operator== does the right thing is 
> pretty important.

Strict weak ordering uses a single operations and does not relate two
operations.  Thus you can test that < imposes a strict weak ordering,
but it can have nothing to do with ==.  What you're testing below
would need some other name.

> I had in mind that I could say
>
> for( each i )
>    for( each i2 )
>      BOOST_CHECK_STRICT_WEAK_ORDERING( *i, *i2 );
>
> which would check something like the following:
>
> if( !(*i < *i2) && !(*i2 < *i) )
> {
>    BOOST_CHECK( *i == *i2 );
> }
> else if( *i < *i2 )
> {
>      BOOST_CHECK( *i != *i2 );
>      BOOST_CHECK( !(*i2 < *i) );
> }
> else
> {
>      BOOST_CHECK( *i2 < *i );
>      BOOST_CHECK( !(*i2 < *i) );
> }

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