Re: [Boost-users] updating mpl::map to 1.34

From: David Abrahams (dave_at_[hidden])
Date: 2006-12-14 17:15:29

"Ovanes Markarian" <om_boost_at_[hidden]> writes:

> Now I have a question regarding iteration through the map. Would you
> expect this sample to work:
>
>
> 	typedef mpl::map
> 			<
> 				mpl::pair<int, int>
> 			,	mpl::pair<int, double>
> 			,	mpl::pair<int, char[20]>
> 			,	mpl::pair<int, char>
> 			>			seq_t;
>
> 	typedef mpl::begin<seq_t>::type		begin_map;
> 	typedef mpl::apply
> 		<
> 			mpl::insert<mpl::_1, mpl::_2>
> 			, mpl::vector<>
> 			, begin_map
> 		>::type				vector_with_one_elem;

No.

I'm not sure what you're trying to do here, but it fails for the same
reason that this fails:

   mpl::insert<mpl::vector<>, begin_map>::type

The two-argument form of mpl::insert only works for inserting into
associative sequences.  vector is not an associative sequence.

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