Consider
template<class Y> struct foo
{
template <class ForwardIt>
foo(ForwardIt first, ForwardIt last);
};
In order to implement the constructor, I've written
template<class Y, class ForwardIt> foo(ForwardIt first, ForwardIt last)
{
// ToDo - code here
}
But this generates a compile error to the effect that it cannot match that definition with a declaration.
What am I doing wrong? I'm using a C++11 compiler.
There are two issues in your code. First, you're missing the name of the class in the function definition outside of the class's body, which basically means you're declaring a freestanding function that has nothing to do with the class or its member function (in this case it is illegal because your function does not have a return type hence cannot be a freestanding function).
Secondly, you must use distinct template declarations for your class template parameters and member function template parameters.
You need:
template<class Y>
template<class ForwardIt>
foo<Y>::foo(ForwardIt first, ForwardIt last)
{
// ToDo - code here
}
template<class Y>
template<class ForwardIt>
foo<Y>::foo(ForwardIt first, ForwardIt last)
{
}
is the correct way to define this.
