From f0f24b48836d65af723c6a89dd43b91b94162a04 Mon Sep 17 00:00:00 2001
From: "Hintz Martin (XC-AD/ESW1-J1)" <martin.hintz@de.bosch.com>
Date: Wed, 3 Mar 2021 14:47:04 +0100
Subject: [PATCH] iox-#591 Added void_t to type_traits

Signed-off-by: Hintz Martin (XC-AD/ESW1-J1) <martin.hintz@de.bosch.com>
---
 .../include/iceoryx_utils/cxx/type_traits.hpp |  3 ++
 .../iceoryx_utils/internal/cxx/expected.inl   |  2 +-
 .../test/moduletests/test_cxx_type_traits.cpp | 38 +++++++++++++++++++
 3 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/iceoryx_utils/include/iceoryx_utils/cxx/type_traits.hpp b/iceoryx_utils/include/iceoryx_utils/cxx/type_traits.hpp
index 2cfd0701e4..f0e180d4e0 100644
--- a/iceoryx_utils/include/iceoryx_utils/cxx/type_traits.hpp
+++ b/iceoryx_utils/include/iceoryx_utils/cxx/type_traits.hpp
@@ -72,6 +72,9 @@ template <typename T1, typename T2>
 using not_same = typename std::
     integral_constant<bool, !bool(std::is_same<typename std::decay<T1>::type, typename std::decay<T2>::type>::value)>;
 
+/// @brief Maps a sequence of any types to the type void
+template <typename...>
+using void_t = void;
 } // namespace cxx
 } // namespace iox
 
diff --git a/iceoryx_utils/include/iceoryx_utils/internal/cxx/expected.inl b/iceoryx_utils/include/iceoryx_utils/internal/cxx/expected.inl
index d9168657d3..a9495d1729 100644
--- a/iceoryx_utils/include/iceoryx_utils/internal/cxx/expected.inl
+++ b/iceoryx_utils/include/iceoryx_utils/internal/cxx/expected.inl
@@ -29,7 +29,7 @@ struct HasInvalidStateMember : std::false_type
 {
 };
 template <typename T>
-struct HasInvalidStateMember<T, std::void_t<decltype(T::INVALID_STATE)>> : std::true_type
+struct HasInvalidStateMember<T, iox::cxx::void_t<decltype(T::INVALID_STATE)>> : std::true_type
 {
 };
 template <typename... T>
diff --git a/iceoryx_utils/test/moduletests/test_cxx_type_traits.cpp b/iceoryx_utils/test/moduletests/test_cxx_type_traits.cpp
index 8609d1e36e..5f7e0c2ff8 100644
--- a/iceoryx_utils/test/moduletests/test_cxx_type_traits.cpp
+++ b/iceoryx_utils/test/moduletests/test_cxx_type_traits.cpp
@@ -59,3 +59,41 @@ TEST(TypeTraitsTest, NotSameIsFalse)
     auto sut = not_same<int, int>::value;
     EXPECT_FALSE(sut);
 }
+
+namespace iox
+{
+namespace cxx
+{
+namespace test
+{
+template <typename, typename = void>
+struct has_mytype_as_member : std::false_type
+{
+};
+
+template <typename T>
+struct has_mytype_as_member<T, void_t<typename T::myType>> : std::true_type
+{
+};
+} // namespace test
+} // namespace cxx
+} // namespace iox
+
+TEST(TypeTraitsTest, NoTypeAsMemberIsFalse)
+{
+    struct Sut
+    {
+    };
+
+    EXPECT_FALSE(iox::cxx::test::has_mytype_as_member<Sut>::value);
+}
+
+TEST(TypeTraitsTest, MyTypeAsMemberIsTrue)
+{
+    struct Sut
+    {
+        using myType = int;
+    };
+
+    EXPECT_TRUE(iox::cxx::test::has_mytype_as_member<Sut>::value);
+}