If I have a template class defined as:
#ifndef A_HPP
#define A_HPP
template<class T>
class A
{
public:
int doSomething(int in, bool useFirst);
private:
template<int CNT>
class B
{
public:
int doSomething(int in);
};
B<2> first;
B<3> second;
};
#include "a_imp.hpp"
#endif
Now I can go about having a declaration for A::doSomething in an implementation header file like this
#ifndef A_IMP_HPP
#define A_IMP_HPP
template<class T>
int A<T>::doSomething(int in, bool useFirst)
{
if (useFirst)
return first.doSomething(in);
return second.doSomething(in);
}
#endif
However I do not know how I go about making the declaration for the child class's method. Is it even possible or do I have to do one of the other two ways I can think of doing this, namely defining the methods in the main header or declare the class outside of A.
Please note that I am using C++11 so if this is only doable in that it will still work for me, though a C++98 solution would be good for other people.
Not sure if this is what you're asking, but I guess you need something like this:
template<class T>
template<int CNT>
int A<T>::B<CNT>::doSomething(int in)
{
return /*...*/;
}
Note that the template keyword appears twice, first for the template parameters of A, then for the parameters of nested class B.
Collected from the Internet
Please contact [email protected] to delete if infringement.
Comments