2009/6/28 Zachary Turner

Is there a way, using some combination of boost preprocessor and mpl, that I can write a class

template class foo { public:

void foo(T arg1, T arg2, ..., T argn); };

In other words, generate a function that requires n arguments where n is a template parameter?

Using preprocessor you can generate a set of functions taking from 0 to M (some predefined constant) arguments. Inside of these functions static assert that number of arguments is equal to n. If a caller calls a function with wrong number of arguments, the compile error will occur, which is exactly what you need. #include <iostream> #include #include #define M 10 template struct foo { #define BOOST_PP_LOCAL_MACRO(Q) \ void bar(BOOST_PP_ENUM_PARAMS(Q, T arg)) { \ BOOST_STATIC_ASSERT(Q == N); \ std::cout << "I'm bar's body" << std::endl; \ } #define BOOST_PP_LOCAL_LIMITS (0, M) #include BOOST_PP_LOCAL_ITERATE() }; int main() { foo f; f.bar(1, 2); // Works. f.bar(1, 2, 3); // Does not work. } Roman Perepelitsa.