Value Category (lvalue and rvalue)

Learned in CS247 - Software Engineering Principles. Used for the Move Assignment Operator.

Every expression in C++ has both type and a Value Category.

Lvalue

An lvalue is any expression that you can take the address of.

For example:

int x = 5;
f(x);

• In the above, this expression x - we can take its address, therefore it is an lvalue.

Rvalue

An rvalue is a temporary value, it will be destroyed “soon”.

f(5);

• 5 is an rvalue, as we cannot take the address of 5.