prog.cpp: In instantiation of ‘bool operator!=(const Comparisons<Derived>&, const Comparisons<Derived>&) [with Derived = int]’:
prog.cpp:23:20: required from here
prog.cpp:13:25: error: invalid static_cast from type ‘const Comparisons<int>’ to type ‘const int&’
const Derived& d1 = static_cast<const Derived&>(lhs);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.cpp:14:25: error: invalid static_cast from type ‘const Comparisons<int>’ to type ‘const int&’
const Derived& d2 = static_cast<const Derived&>(rhs);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~