Suppose I have some template class forward declared and I want to typedef a shared pointer to it. How would I do this?
template<typename T> class Arg;
typedef std::tr1::shared_ptr<Arg> ArgPtr; // Compiler error
You also probably want template typedef. Read up on Sutter's article.
In C++03, you need a hack as:
template <typename Arg> struct ArgPtr {
typedef std::shared_ptr<Arg> ArgPtrType;
};
In C++11, you can use template aliasing directly with the using
keyword:
template <typename T>
using ArgPtrType = std::shared_ptr<Arg<T>>;