Re: [Boost-users] [fusion] How to transform types of fusion::map ?

Hi Zeljko, On Wed, Sep 17, 2008 at 8:25 AM, Zeljko Vrba wrote:

A very concrete question:

I have map, pair, ..> as input. How do I produce map, pair on output?

Take a look at `transform` (algorithm/transformation/transform in the docs), I think that should work for you. If you are only interested in transforming the type, mpl::transform might work better (fusion's transform is lazy, so to get the map type out you'd also need `result_of::as_map` (container/conversion/metafunctions in the docs)). If you want to use mpl's transform on a fusion map, #include

- what is the purpose of for_each metafunction when the docs say that it always returns void? (and no side-effects are possible at compile-time)

fusion is not just compile-time - the types are compile time but the values are run-time. Regardless, the function invoked by for_each can have side-effects (there is also an mpl for_each which is useful). Best, Stjepan