Re: Conversion policies

Daniel Wallin <[email protected]> writes:

> Ok I've given this some thought. The issue is that we need to keep the
> converter
> object instances on the stack of the invoker function, to be able to have
> storage between check() and to_cxx(). This is important for lvalue-conversions
> which can perform the entire conversion in the checking part, and stores the
> pointer. It's likely important for other more advanced policies as well, which
> could need intermediate storage.

Right, OK:

template<class R, class A0, class A1, class Policies>
ret_type invoke(R(*fn)(A0, A1), const Policies& policies, ArgTuple t)
{
    typename Policies::conversions_type converters(policies);

    if !(
         converters.check(_1, identity<A0>(), t[0])
       , converters.check(_2, identity<A1>(), t[1])
    )
    return kOverloadFailed;
        
    return converters.from_cxx(
        fn(
             converters.to_cxx(_1, identity<A0>(), t[0])
           , converters.to_cxx(_2, identity<A1>(), t[1])
        )
    );
}


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



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