check define TARGET_RT_MAC_CFM
check define __FreeBSD__
check define __MACH__
check define _WIN32

if ! cfg:set 'type-safe reference scoping' "$(c++:compile "
    int value_(0);

    struct Scope {
    };

    struct ScopeTest : Scope {
    ~ScopeTest() {
        value_ *= 2;
    } };

    int main() {
        {
            const Scope &scope = ScopeTest();
            value_ += 1;
        }

        return value_ == 2 ? $yes : $no;
    }
")"; then
    fatal 'sorry, deal breaker.'
fi

cfg:set 'delayed ambiguity detection' "$(success c++:pre-compile "
    template <bool Test_>
    class IfTrue;

    template <typename Type_>
    IfTrue<sizeof(Type_) == sizeof(int)>
    f(const Type_ &);

    template <typename Type_>
    IfTrue<sizeof(Type_) != sizeof(int)>
    f(const Type_ &);
")"

cfg:set 'operator template arguments' "$(success c++:pre-compile "
    template <bool>
    struct I {
    };

    template <typename>
    struct N {
        static const bool v = false;
    };

    template <typename, typename T>
    I<!N<T>::v> g(T) {
    }

    void f() {
        g<char>(0);
    }
")"