Tobias Schwinger <tschwinger@neoscientists.org> writes:
Tobias Schwinger wrote:
Hi, What is the best way to convert the result of a mutating mpl intrinsic metafunction (such as 'mpl::push_back', for example) to numbered form ('vectorN<a1,a2,..>') ?
I was hoping Aleksey would answer, but he seems to have dropped off the face of the earth (temporarily, I hope). I am guessing that Aleksey would say "don't do that!" He has always maintained that relying on sequence type identity was just wrong.
I tried using the type-member (which only works on some compilers - not with GCC for example) and figure 'copy' could probably do the trick (but is a quite complex operation) so there might be a better recipe for this. In a library I'm currently working on, I use a decorator pattern to make
[ This refers to: http://tinyurl.com/6c35p ]
a class model of a sequence it holds (i.e. give it a tag type member and specialize *_impl with delegate semantics). After applying the delegate metafunction I need the sequence in a form I can match with partial specialization.
I don't know the details of your problem, so I can't say for sure, but you might consider using partial specialization based on the sequence's tag and/or size. -- Dave Abrahams Boost Consulting www.boost-consulting.com