On Tue, Feb 9, 2010 at 3:49 PM, Gabriel Redner <gredner@gmail.com> wrote:

Hi all,

I'm trying to use fusion vectors with more than 10 elements, but I'm running into some trouble.

I'm using fusion as an implementation detail of some header-based tools, which get included (often indirectly) by some translation units.  The tools require large fusion vectors, but I don't want client code (i.e. the .cpp files) to have to care about this.  I was under the impression that I could just add:

#define FUSION_MAX_VECTOR_SIZE 20 #include <boost/fusion/container.hpp>

in my tool's header file, and be off to the races.  It seems that this works only if no other fusion header has been included previously in the same translation unit:

#include <boost/fusion/container.hpp> ... #define FUSION_MAX_VECTOR_SIZE 20 #include <boost/fusion/container.hpp> ... // Error - too many template arguments! boost::fusion::make_vector(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15);

I really don't want to have to track down every translation unit which is (usually indirectly) including my tool's header.  I am under the impression that boost::function is fine with client code redefining its limit macro and re-including its header, but perhaps fusion does not have the same feature?

I also realize that for vector itself I can just include vectorN.hpp and use vectorN<...>, but if I want to use the generation functions (make_vector, vector_tie) it seems I'm stuck.  Is there a workaround, or just something obvious that I'm doing wrong?

make_vector/etc.. just use vector directly internally, you can do the same in their place with the vectorN functions.