What does `invalid initialization of non-const reference` mean?

Question

When compiling this code I get the following error:

In function \'int main()\': Line 11: error: invalid initialization of non-const reference of typ

Answer 1

In C++ temporaries cannot be bound to non-constant references.

Main<int> &mainReference = Main<int>::tempFunction();

Here you are trying to assign the result of an rvalue expression to a non-constant reference mainReference which is invalid.

Try making it const