why put a reference in an "operator" when overloading an operand

[nooblet001]

Hello. I watched this lesson about function overloading(about increments) and I'm just wondering why he placed a reference before the "operator". What's the purpose of putting a reference in there? I thought a "reference" is used in data variables?

Mass &operator++(int)
	{
		Mass a = *this;
		a++;
		return a;
	}

[LB]

The ampersand does not come before the operator keyword. It comes after the Mass identifier.

This example is identical:

using ReferenceToMass = Mass &;

ReferenceToMass operator++(int)
{
    Mass a = *this;
    a++; //infinite recursion
    return a; //dangling reference; possible crash/corruption later
}

The code is still incorrect, however.

[TwilightSpectre]

First, know that what you have there is a very bad idea.

I'll get to that in a bit, but first explaining. Whenever you have the '&', you have a reference. What you are doing is saying that the return type is 'reference to Mass'. Therefore, rather than returning a copy of the object, you are returning the reference to the object.

Now, do you see the problem? a goes out of scope at line 6 - it will generally be cleaned from memory. However, you are also giving something a reference to that (now gone) object, which can be accessed or modified. Due to this, often your program will crash due to memory access violations.