header only library to help implementing concept for a class

implement.hpp

// This header only library is usued to check whether a class satisfies a concept.
// When compiling, an error will happen if the class doesn't satisfy the concept.
// IDEs like QtCreator and CLion will also display an error for it whiling editing.
// This is useful when you want to satisfy a concept by implementing methods one by one.
// (without checking the definition of the concept over time).
// usage: implement(class, concept, unique name for the implementation)
// define DISABLE_IMPL_CHECK to disable the macro.

#ifndef IMPLEMENT_CONCEPT_HPP
#define IMPLEMENT_CONCEPT_HPP
#ifndef DISABLE_IMPL_CHECK
#define implement(cl, con, name) \
template <con T> class __sat_check_##name##_c {};\
static __sat_check_##name##_c<cl> __sat_check_##name __attribute__((unused));
#else
#define implement(cl, con, name) ;
#endif
#endif