Re: [Boost-users] [mpl::map & mpl::transform] Problems using mpl::map in mpl::for_each

"Ovanes Markarian" writes:

Hello,

I have some slightly different code, which is presented in C++ Template Metaprogramming book to use the mpl::for_each function:

mpl::for_each< mpl::transform >::type >(dispatcher_type());

mpl::for_each >(dispatcher_type()); would be simpler

The deviation from the book is that my seq it not mpl::vector<...>, but mpl::map<...>

In the docs is written, that mpl::transform operates on Forward Sequence. In the doc of forward sequence is stated that mpl::map is a model of it.

The last release of mpl::map had some considerable bugs. Have you tried the latest version from the CVS HEAD (or RC_1_34_0)?

Unfortunately this code does not compile. I could transform the map to vector, but I would not like doing it, since that would cost compile time and slow down the compilation. Is it a known issue or should not I expect map to work with transform?

The code could "not compile" for many other reasons than that "map doesn't work with transform." Have you tried to compile typedef mpl::transform >::type x;

I also tried using itertors on seq, but that did not help.

I think we'll need a lot more detail to be able to help you. -- Dave Abrahams Boost Consulting www.boost-consulting.com