class in OOP language and type

In programming language theory, a type is a set of values. E.g. the type "int" is the set of all integer values.

In OOP languages, a class is a type, is it?

When a class is defined with more than one members, e.g.

class myclass{
    int a; 
    double b;
}

When we talk about a class, do we mean

• "(a,b) where a is an int and b is a double", or


• "{(x,y) | x is any int, y is any double}"?

What does an instance of myclass mean?

• "(a,b) where a is an int and b is a double", or


• an object which occupies a memory space and which can (not necessarily, i.e. can be empty) store (x,y), where x is any int and y is any double?