Merge pull request #21041 from sivanov-work:gin_gout_concept

G-API: GAPI introduce compile guard for some types for gin/gout params passing

* Initial for taged solution

* Move out tags to gtags.hpp & add protection for own::Mat

* Add compile guard to proper place

* Fix MACRO concat

* Add unit tests

* Remove class MACRO injection due to Python3

* Revert back unproper changes

* Apply comments: reuse shape from traits

* Throw away unused gtags

* Apply comments

* Handle own::*

* Fix test

* Fix test(1)

* Fix unix build

* Try on type list

* Apply comments

* Apply comments

* Fix warning

modules/gapi/include/opencv2/gapi/gtype_traits.hpp

@@ -19,11 +19,25 @@
 #include <opencv2/gapi/streaming/source.hpp>
 #include <opencv2/gapi/media.hpp>
 #include <opencv2/gapi/gcommon.hpp>
+#include <opencv2/gapi/util/util.hpp>
+#include <opencv2/gapi/own/convert.hpp>
 
 namespace cv
 {
 namespace detail
 {
+    template<typename, typename = void>
+    struct contains_shape_field : std::false_type {};
+
+    template<typename TaggedTypeCandidate>
+    struct contains_shape_field<TaggedTypeCandidate,
+                                void_t<decltype(TaggedTypeCandidate::shape)>> :
+        std::is_same<typename std::decay<decltype(TaggedTypeCandidate::shape)>::type, GShape>
+    {};
+
+    template<typename Type>
+    struct has_gshape : contains_shape_field<Type> {};
+
     // FIXME: These traits and enum and possible numerous switch(kind)
     // block may be replaced with a special Handler<T> object or with
     // a double dispatch
@@ -181,10 +195,16 @@ namespace detail
         }
         template<typename U> static auto wrap_in (const U &u) -> typename GTypeTraits<T>::strip_type
         {
+            static_assert(!(cv::detail::has_gshape<GTypeTraits<U>>::value
+                            || cv::detail::contains<typename std::decay<U>::type, GAPI_OWN_TYPES_LIST>::value),
+                          "gin/gout must not be used with G* classes or cv::gapi::own::*");
             return GTypeTraits<T>::wrap_in(u);
         }
         template<typename U> static auto wrap_out(U &u) -> typename GTypeTraits<T>::strip_type
         {
+            static_assert(!(cv::detail::has_gshape<GTypeTraits<U>>::value
+                            || cv::detail::contains<typename std::decay<U>::type, GAPI_OWN_TYPES_LIST>::value),
+                          "gin/gout must not be used with G* classses or cv::gapi::own::*");
             return GTypeTraits<T>::wrap_out(u);
         }
     };

modules/gapi/include/opencv2/gapi/opencv_includes.hpp

@@ -14,6 +14,12 @@
 #  include <opencv2/core/cvdef.h>
 #  include <opencv2/core/types.hpp>
 #  include <opencv2/core/base.hpp>
+#define GAPI_OWN_TYPES_LIST     cv::gapi::own::Rect,                           \
+                                cv::gapi::own::Size,                           \
+                                cv::gapi::own::Point,                          \
+                                cv::gapi::own::Point2f,                        \
+                                cv::gapi::own::Scalar,                         \
+                                cv::gapi::own::Mat
 #else   // Without OpenCV
 #  include <opencv2/gapi/own/cvdefs.hpp>
 #  include <opencv2/gapi/own/types.hpp>  // cv::gapi::own::Rect/Size/Point
@@ -28,6 +34,8 @@ namespace cv {
     using Scalar  = gapi::own::Scalar;
     using Mat     = gapi::own::Mat;
 }  // namespace cv
+#define GAPI_OWN_TYPES_LIST     cv::gapi::own::VoidType
+
 #endif // !defined(GAPI_STANDALONE)
 
 #endif // OPENCV_GAPI_OPENCV_INCLUDES_HPP

modules/gapi/include/opencv2/gapi/own/types.hpp

@@ -143,6 +143,7 @@ inline std::ostream& operator<<(std::ostream& o, const Size& s)
     return o;
 }
 
+struct VoidType {};
 } // namespace own
 } // namespace gapi
 } // namespace cv

modules/gapi/include/opencv2/gapi/util/util.hpp

@@ -116,6 +116,13 @@ namespace detail
         using type = std::tuple<Objs...>;
         static type get(std::tuple<Objs...>&& objs) { return std::forward<std::tuple<Objs...>>(objs); }
     };
+
+    template<typename... Ts>
+    struct make_void { typedef void type;};
+
+    template<typename... Ts>
+    using void_t = typename make_void<Ts...>::type;
+
 } // namespace detail
 
 namespace util