The definition of l-value and r-value in C++

Accroding to the MSDN website, the definition of l-value like below:

Expressions that refer to memory locations are called “l-value” expressions. An l-value represents a storage region’s “locator” value, or a “left” value, implying that it can appear on the left of the equal sign (=). L-values are often identifiers.

####Any of the following C expressions can be l-value expressions:
An identifier of integral, floating, pointer, structure, or union type
A subscript ([ ]) expression that does not evaluate to an array
A member-selection expression (–> or .)
A unary-indirection (*) expression that does not refer to an array
An l-value expression in parentheses
A const object (a nonmodifiable l-value)

By contrast to l-value, r-value refer to the expression you can not get the memory-locations. Because of not being able to get the locations, so you cannot put the r-value at the left of equal sign(=).