Hi, I have a simple template function that takes one argument. For example: template< typename t_type > void foo( t_type param ) { } I want to restrict the type of t_type to a certain subset of types, such as 'char' or 'wchar_t'. If the user passes in any type other than those two types, the compiler should not be able to find an overload for foo() that matches the argument types. Note that I would also be using boost::enable_if to test this condition, however I do not see anything in type_traits or anywhere else to perform such a test. I thought of using mpl::vector to create a list of types the function would take and using enable_if to check if the type is in the container, but this seems like a lot of work. I want to see if there is a simpler, more compact solution. Thanks.