online compiler and debugger for c/c++

#include <iostream> #include <functional> // needed for std::equal_to #include <iterator> using namespace std; namespace { using namespace std; /** * LIFTED -@todo add docs/reference * from Stroustrup C++11 book - page 800 */ struct substitution_failure { }; /** * LIFTED -@todo add docs/reference * from Stroustrup C++11 book - page 800 */ template < typename T > struct substitution_succeeded:true_type { }; template <> struct substitution_succeeded <substitution_failure >:false_type { }; #define STROIKA_FOUNDATION_CONFIGURATION_DEFINE_HAS(NAME, XTEST) \ namespace Private_ { \ template <typename T> \ struct NAME##_result_impl { \ template <typename X> \ static auto check (const X& x) -> decltype (XTEST); \ static substitution_failure check (...); \ using type = decltype (check (declval<T> ())); \ }; \ } \ template <typename T> \ using NAME##_result = typename Private_::NAME##_result_impl<T>::type; \ template <typename T> \ struct has_##NAME : integral_constant<bool, not is_same<NAME##_result<T>, substitution_failure>::value> { \ }; \ template <typename ITERABLE> \ constexpr bool Has##NAME##_v = has_##NAME<ITERABLE>::value; STROIKA_FOUNDATION_CONFIGURATION_DEFINE_HAS (eq, (x == x)); // SEE https://stroika.atlassian.net/browse/STK-749 STROIKA_FOUNDATION_CONFIGURATION_DEFINE_HAS (equal_to, (static_cast<bool> (std::equal_to<X>{}(x, x)))); template <typename T1, typename T2> \ struct has_eq<std::pair<T1, T2>> : integral_constant<bool, has_eq<T1>::value && has_eq<T1>::value> {}; class SimpleClassWithoutComparisonOperators { public: SimpleClassWithoutComparisonOperators (size_t v); SimpleClassWithoutComparisonOperators (const SimpleClassWithoutComparisonOperators & f); ~SimpleClassWithoutComparisonOperators (); size_t GetValue () const; static size_t GetTotalLiveCount (); //explicit operator size_t () const { return fValue; } SimpleClassWithoutComparisonOperators operator+ (const SimpleClassWithoutComparisonOperators & rhs) const { return SimpleClassWithoutComparisonOperators (fValue + rhs.fValue); } private: size_t fValue; int fConstructed; static size_t sTotalLiveObjects; }; static_assert (!has_eq < SimpleClassWithoutComparisonOperators >::value); using PAIR_ = std::pair < SimpleClassWithoutComparisonOperators, SimpleClassWithoutComparisonOperators >; static_assert (!has_eq < PAIR_ >::value); static_assert (has_eq <std::pair<int, int> >::value); } int main() { cout << "Hello World"; return 0; }