Return class ref from class template function

Question

Given a class template:

template <typename T>
class my_class
{
public:
    my_class& test1() { return *this; }
    // OR
    my_class<T>& test2() { return *this; }
}

Is there any difference between return types of test1 and test2?

No, there is no difference – rocambille Sep 29 '16 at 14:21 — rocambille, Sep 29 '16 at 14:21

score 7 · Accepted Answer · edited May 23 '17 at 10:34

7

Is there any difference between return types of test1 and test2?

No. There is a concept called injected-class-name. Within the body of my_class<T>, the name my_class refers to the full type my_class<T>.

We can even take this to its logical conclusion and add:

my_class::my_class::my_class::my_class& test4() { return *this; }

edited May 23 '17 at 10:34

Community

answered Sep 29 '16 at 14:23

Barry

3

Needs more `my_class`. – Hatted Rooster Sep 29 '16 at 14:25
1

injected class name behaves differently in c++03 and c++11, can you add that? – Trevir Sep 29 '16 at 14:26
1

@Trevir I'm not aware of a change in C++11. – Barry Sep 29 '16 at 14:27
1

In c++11 it is possible to used the injected class name as a template argument for a template-template parameter. This was not possible in c++03. – Trevir Sep 29 '16 at 14:29

score 2 · Answer 2 · answered Sep 29 '16 at 14:22

2

No, within the scope my_class<T>, my_class is an abbreviation for my_class<T>.

answered Sep 29 '16 at 14:22

aschepler

2 Answers2