Detailed Description

A hint to the compiler.

Functors which have all methods based on templates should publicly inherit from this hint and define a nested template class deduce_result_type that can be used to deduce the methods' return types.

adaptor_base inherits from the functor_base hint so derived types should also have a result_type defined.

Adaptors don't inherit from this type directly. They use use sigc::adapts as a base type instead. sigc::adaptors wraps arbitrary functor types as well as function pointers and class methods.