Re: [boost] [mpl] is there a or_seq like logical metafunction?

From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2008-03-07 13:02:29

AMDG

Giovanni Piero Deretta wrote:
> Hum, I think it actually does short circuit evaulation (haskel-like):
>
> struct bad {};
> typedef mpl::vector<mpl::false_, mpl::false_, bad> ffb_v;
> typedef mpl::vector<mpl::false_, mpl::false_, fail> tfb_v;
>
> or_seq<ffb_v> gives the expected compile time error (error: no type
> named 'type' in 'struct fail') , while
> or_seq<tfb_v> compiles fine (and yelds true).
>   

The short circuiting is done by and_ and or_, what I meant is that
you still have to iterate through the entire sequence.

In Christ,
Steven Watanabe