During c++ now there was conversation about if this could be constexpr.
This won't work with member function
https://github.com/bemanproject/copyable_function/blob/main/include/beman/copyable_function/copyable_function_helper.h#L21
you can do it by making it union with void * and in constexpr always allocate and using use construct_at
During c++ now there was conversation about if this could be constexpr.
This won't work with member function
https://github.com/bemanproject/copyable_function/blob/main/include/beman/copyable_function/copyable_function_helper.h#L21
you can do it by making it union with void * and in constexpr always allocate and using use construct_at