args_constraints.cpp 1.6 KB

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  1. /*
  2. Copyright Barrett Adair 2016-2017
  3. Distributed under the Boost Software License, Version 1.0.
  4. (See accompanying file LICENSE.md or copy at http ://boost.org/LICENSE_1_0.txt)
  5. */
  6. #include <boost/callable_traits/args.hpp>
  7. #include "test.hpp"
  8. struct foo;
  9. template<typename T>
  10. struct is_substitution_failure_args {
  11. template<typename>
  12. static auto test(...) -> std::true_type;
  13. template<typename U,
  14. TRAIT(boost::callable_traits::args, U, std::tuple)* = nullptr>
  15. static auto test(int) -> std::false_type;
  16. static constexpr bool value = decltype(test<T>(0))::value;
  17. };
  18. int main() {
  19. CT_ASSERT(is_substitution_failure_args<int>::value);
  20. CT_ASSERT(is_substitution_failure_args<int &>::value);
  21. CT_ASSERT(is_substitution_failure_args<int (** const &)()>::value);
  22. CT_ASSERT(is_substitution_failure_args<int (foo::** &)()>::value);
  23. CT_ASSERT(is_substitution_failure_args<int (foo::** const)()>::value);
  24. CT_ASSERT(is_substitution_failure_args<int (foo::** const &)()>::value);
  25. CT_ASSERT(is_substitution_failure_args<int (foo::** volatile)()>::value);
  26. CT_ASSERT(!is_substitution_failure_args<int (* const &)()>::value);
  27. CT_ASSERT(!is_substitution_failure_args<int (foo::* &)()>::value);
  28. CT_ASSERT(!is_substitution_failure_args<int (foo::* const)()>::value);
  29. CT_ASSERT(!is_substitution_failure_args<int (foo::* const &)()>::value);
  30. CT_ASSERT(!is_substitution_failure_args<int (foo::* volatile)()>::value);
  31. auto lambda = [](){};
  32. CT_ASSERT(!is_substitution_failure_args<decltype(lambda)&>::value);
  33. CT_ASSERT(is_substitution_failure_args<void>::value);
  34. }