Types of Values
- lvalue:
++x,x = 1,cout << '...',"hello world" - xvalue (expiring value):
std::move(ptr1)can be considered as a named rvalue, distinguished from unnamed pure rvalue (prvalue) - prvalue: smart_ptr ptr1{
new circle()},return circle()
Value Categories
C++ has unique concepts of value categories - lvalue/rvalue:
Value and Reference Types Comparison
| Language | Value Types | Reference Types |
|---|---|---|
| C++ | All primitive types, enums, structs, unions, classes | References (&) and pointers (*) |
| Java | Primitive types (numbers, etc.) | Classes |
| Python | None | All |
C++ primarily uses value semantics - parameters are passed by value (copied) by default.