Christophe Henry writes:

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Christophe Henry writes:

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You can also provide your own instances inside a front-end definition, thus eliminating the problem completely, as in:

http://www.boost.org/doc/libs/1_46_0/libs/msm/doc/HTML/examples/SimpleTutori...

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A couple more questions. I think you may be missing some more const specifiers in the trunk code. In common.hpp for instance, I think the following #define BOOST_MSM_EUML_EVENT(instance_name) \ struct instance_name ## _helper : msm::front::euml::euml_event{ \ instance_name ## _helper(){} \ instance_name ## _helper const& operator()(){return *this;} }; \ instance_name ## _helper const instance_name = instance_name ## _helper(); should be #define BOOST_MSM_EUML_EVENT(instance_name) \ struct instance_name ## _helper : msm::front::euml::euml_event{ \ instance_name ## _helper(){} \ instance_name ## _helper const& operator()() const {return *this;} }; \ instance_name ## _helper const instance_name = instance_name ## _helper(); If the operator() is not const then it can't be called on the defined instance. Also, the addition of "= instance_name ## _helper();" makes the macros unusable in class definitions since instance_name is not static.