Quote:If a function-definition or member-declarator declares a member function 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 or member-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 is defined within a static member function as it is within a non-static member function). [Note: the type and value category is defined even for the case of a static member function because declaration matching does not occur until the complete declarator is known, and this may be used in the trailing-return-type of the declarator. —end note]

Otherwise, if a member-declarator declares a non-static data member (9.2 [class.mem]) of a class X, the expression this is a prvalue of type “pointer to X” within the optional brace-or-equal-initializer. It shall not appear elsewhere in the member-declarator.