Deducing this, i wish: my current approach just uses a macro to stamp out all the required overloads. The quadruplication is code-generated.

no_deducing_this_macro.hpp

#include <utility>

#define FORALL_CONSTREFS(mac)                                                  \
  mac(const, &, ) mac(, &, ) mac(, &&, std::move) mac(const, &&, std::move)

class ExampleIntWrapper {
 public:
#  define OVERLOADS_PLEASE(const_, ref_, move_)                                \
    int const_ ref_ data() const_ ref_ { return move_(data_); }
  FORALL_CONSTREFS(OVERLOADS_PLEASE)

 private:
  int data_;
};