Annex D (normative) Compatibility features [depr]

A call wrapper may have a weak result type. If it does, the type of its member type result_­type is based on the type T of the wrapper's target object:

• (1.1)

  if T is a pointer to function type, result_­type shall be a synonym for the return type of T;

• (1.2)

  if T is a pointer to member function, result_­type shall be a synonym for the return type of T;

• (1.3)

  if T is a class type and the qualified-id T​::​result_­type is valid and denotes a type ([temp.deduct]), then result_­type shall be a synonym for T​::​result_­type;

• (1.4)

  otherwise result_­type shall not be defined.