Why does this program compile fine in C++14 but not in a C++11 compiler?

Question

I recently tested the simple following program on an online compiler. See live demo here. It compiles fine & gives the expected output but when I tested it on Dev C++ IDE it fails during the compilation.

Here is my program:

#include <iostream>
class Test
{
    int s=9;
    public:
    int get_s()
    {
        return s;
    }
};
int main()
{
    Test s;
    Test& t{s};      // error in C++11 but not in C++14 why???
    std::cout<<t.get_s();
} 

It gives me following error:

[Error] invalid initialization of non-const reference of type 'Test&' from an rvalue of type '<brace-enclosed initializer list>'

I also tried it on code blocks 13.12 IDE & it gives me the same error as Dev C++ gives.

Is this a new C++14 feature? Why is it not working in a C++11 compiler?

Answer 1

It works on C++14 and also works on C++11. You're very likely using an out-of-date compiler.

There's a fixed bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50025) for your exact issue (cfr. DR 1288)

C++0x initialization syntax doesn't work for class members of reference type

Quoting from Jonathan Wakely

The original C++11 rules required a temporary to be created there and the reference member binds to that temporary.

Sources: Defect Report 1288