C++ uses references in many places

SomeObject obj1;

Someobject obj2;

obj2 = obj1;

… that’s why we did this detour. Consider this

int i = 3;

int j;

j = i;

is conceptually the same as

and results in a “call”

obj2.operator= (const SomeObject &obj1);

Some constructs:

obj2 = obj1;

SomeObject obj2 = obj1;

obj3 = obj1 + obj2;

obj2.operator= (const SomeObject &obj1);

obj2 (const &obj1); // “copy constructor”

obj3 = SomeObject.operator+ ( const &obj1, const &obj2);

End of detour - let’s now get back to our operators.

the compiler does this with a reference

If you want to deal with operators, you have to understand the object references.