7 Expressions [expr]

7.5 Primary expressions [expr.prim]

7.5.2 This [expr.prim.this]

The keyword this names a pointer to the object for which a non-static member function ([class.this]) is invoked or a non-static data member's initializer ([class.mem]) is evaluated.

If a declaration declares a member function or member function template of a class X, the expression this is a prvalue of type “pointer to cv-qualifier-seq X” between the optional cv-qualifier-seq and the end of the function-definition, member-declarator, or declarator.

It shall not appear before the optional cv-qualifier-seq and it shall not appear within the declaration of a static member function (although its type and value category are defined within a static member function as they are within a non-static member function).

[Note 1:

This is because declaration matching does not occur until the complete declarator is known.

— end note]

[Note 2:

In a trailing-return-type, the class being defined is not required to be complete for purposes of class member access .

Class members declared later are not visible.

[Example 1: struct A { char g(); template<class T> auto f(T t) -> decltype(t + g()) { return t + g(); } }; template auto A::f(int t) -> decltype(t + g()); — end example]

— end note]

Otherwise, if a member-declarator declares a non-static data member of a class X, the expression this is a prvalue of type “pointer to X” within the optional default member initializer .

It shall not appear elsewhere in the member-declarator.

The expression this shall not appear in any other context.

[Example 2: class Outer { int a[sizeof(*this)]; // error: not inside a member function unsigned int sz = sizeof(*this); // OK: in default member initializer void f() { int b[sizeof(*this)]; // OK struct Inner { int c[sizeof(*this)]; // error: not inside a member function of Inner }; } }; — end example]