template<class T>
constexpr auto supportsAPI(T x) -> decltype(x.Method1(), x.Method2(), true_type{}) {
 return {};
}
constexpr auto supportsAPI(...) -> false_type {
 return {};
}

template<class T>
auto compute(T x) -> decltype( enable_if_t< supportsAPI(T{}), int>{}) {
 return x.Method();
}

template<class T>
auto compute(T x) -> decltype( enable_if_t<!supportsAPI(T{}), int>{}) {
 return 0;
}