The standard correctly defines the return type of an assignment operator. Actually, the assignment operation itself doesn’t depend on the return value – that’s why the return type isn’t straightforward to understanding. The return type is important for chaining operations. Consider the following construction: a = b = c;. This should be equal to a … Read more
= is the assignment operator. It sets a variable (the left-hand side) to a value (the right-hand side). The result is the value on the right-hand side. == is the comparison operator. It will only return true if both values are equivalent after coercing their types to the same type. === is a more strict … Read more
Not returning a reference is a waste of resources and a yields a weird design. Why do you want to do a copy for all users of your operator even if almost all of them will discard that value? a = b; // huh, why does this create an unnecessary copy? In addition, it would … Read more
You can’t assign to an array, only copy to it. Use strcpy instead, like strcpy(word, “Jump”);
One use case is the singleton pattern where there can only be exactly one instance of a class. In this case, you need make your constructors and assignment operator= private so that there is no way of creating more than one object. The only way to create an object is via your GetInstance() function as … Read more
There is nothing that makes the shown code snippet inherently UB. However, it is almost certain UB will follow immediately under any normal usage. From [basic.life]/8 (emphasis mine) If, after the lifetime of an object has ended and before the storage which the object occupied is reused or released, a new object is created at … Read more
Firstly, it should be noted that this has nothing to do with the operator being implemented as a friend specifically. It is really about implementing the copy-assignment as a member function or as a non-member (standalone) function. Whether that standalone function is going to be a friend or not is completely irrelevant: it might be, … Read more
This is what the standard says in 12.8 (Copying class objects). Copy construction: Each subobject is copied in the manner appropriate to its type: if the subobject is of class type, the copy constructor for the class is used; if the subobject is an array, each element is copied, in the manner appropriate to the … Read more
That’s the way the language was designed. It is consistent with most languages. Having a variable declaration return anything other than undefined is meaningless, because you can’t ever use the var keyword in an expression context. Having assignment be an expression not a statement is useful when you want to set many variable to the … Read more
No, they are different operators. The copy constructor is for creating a new object. It copies an existing object to a newly constructed object.The copy constructor is used to initialize a new instance from an old instance. It is not necessarily called when passing variables by value into functions or as return values out of … Read more