Is there anyway in C++11 to get member pointer type within a template?
c++, c++11, decltype, member-pointers, templates
Solution
What you are trying to do cannot be done, that is, you cannot use a member pointer as a constant expression unless you have a type. That is, the type of a non-type template argument must be provided, or in other words, there is no type inference for template arguments.
Problem
I know this was not possible in C++03, but I'm hoping there is some new voodoo to allow me to do this. See below: ``` template <class T> struct Binder { template<typename FT, FT T::*PtrTomember> void AddMatch(); }; struct TestType { int i; }; int main(int argc, char** argv) { Binder<TestType> b; b.AddMatch<int,&TestType::i>(); //I have to do this now b.AddMatch<&TestType::i>(); //I'd like to be able to do this (i.e. infer field type) } ``` Is there any way to do this in C++11? Will decltype help? ** UPDATE: Using Vlad's example I Was thinking something like this would work (caveat: I have not compiled as I am building the compiler with decltype support now) ``` template <class T> struct Binder { template<typename MP, FT ft = decltype(MP)> void AddMatch() { //static_assert to make sure MP is a member pointer of T } }; struct TestType { int i; }; int main() { Binder<TestType> b; b.AddMatch<&TestType::i>(); } ``` Would this work?