Merge pull request opencv#16496 from andrey-golubev:unify_g_typed_kernel

Author: alalek

modules/gapi/include/opencv2/gapi/gkernel.hpp

@@ -228,6 +228,20 @@ class GKernelType<K, std::function<R(Args...)> >
     }
 };
 
+namespace detail {
+// This tiny class eliminates the semantic difference between
+// GKernelType and GKernelTypeM.
+template<typename, typename> class KernelTypeMedium;
+
+template<typename K, typename... R, typename... Args>
+class KernelTypeMedium<K, std::function<std::tuple<R...>(Args...)>> :
+    public cv::GKernelTypeM<K, std::function<std::tuple<R...>(Args...)>> {};
+
+template<typename K, typename R, typename... Args>
+class KernelTypeMedium<K, std::function<R(Args...)>> :
+    public cv::GKernelType<K, std::function<R(Args...)>> {};
+} // namespace detail
+
 } // namespace cv
 
 
@@ -256,12 +270,12 @@ class GKernelType<K, std::function<R(Args...)> >
  *
  * @param Class type name for this operation.
  * @param API an `std::function<>`-like signature for the operation;
- *    return type is a single value.
+ *        return type is a single value or a tuple of multiple values.
  * @param Id string identifier for the operation. Must be unique.
  */
-#define G_TYPED_KERNEL_HELPER(Class, API, Id)                               \
-    G_ID_HELPER_BODY(Class, Id)                                             \
-    struct Class final: public cv::GKernelType<Class, std::function API >,  \
+#define G_TYPED_KERNEL_HELPER(Class, API, Id)                                               \
+    G_ID_HELPER_BODY(Class, Id)                                                             \
+    struct Class final: public cv::detail::KernelTypeMedium<Class, std::function API >,     \
                         public G_ID_HELPER_CLASS(Class)
 // {body} is to be defined by user
 
@@ -319,10 +333,7 @@ G_TYPED_KERNEL_HELPER(Class, COMBINE_SIGNATURE(_1, _2, _3, _4, _5, _6, _7, _8, _
  *    return type is a tuple of multiple values.
  * @param Id string identifier for the operation. Must be unique.
  */
-#define G_TYPED_KERNEL_M_HELPER(Class, API, Id) \
-    G_ID_HELPER_BODY(Class, Id)                                             \
-    struct Class final: public cv::GKernelTypeM<Class, std::function API >, \
-                        public G_ID_HELPER_CLASS(Class)
+#define G_TYPED_KERNEL_M_HELPER G_TYPED_KERNEL_HELPER
 // {body} is to be defined by user
 
 #define G_TYPED_KERNEL_M_HELPER_2(Class, _1, _2, Id) \
@@ -358,21 +369,10 @@ G_TYPED_KERNEL_HELPER(Class, COMBINE_SIGNATURE(_1, _2, _3, _4, _5, _6, _7, _8, _
  *
  * @param Class type name for this operation.
  */
-#define G_TYPED_KERNEL_M(Class, ...) __WRAP_VAARGS(GET_G_TYPED_KERNEL(__VA_ARGS__, \
-                                                   G_TYPED_KERNEL_M_HELPER_10, \
-                                                   G_TYPED_KERNEL_M_HELPER_9, \
-                                                   G_TYPED_KERNEL_M_HELPER_8, \
-                                                   G_TYPED_KERNEL_M_HELPER_7, \
-                                                   G_TYPED_KERNEL_M_HELPER_6, \
-                                                   G_TYPED_KERNEL_M_HELPER_5, \
-                                                   G_TYPED_KERNEL_M_HELPER_4, \
-                                                   G_TYPED_KERNEL_M_HELPER_3, \
-                                                   G_TYPED_KERNEL_M_HELPER_2, \
-                                                   G_TYPED_KERNEL_M_HELPER)(Class, __VA_ARGS__)) \
-// {body} is to be defined by user
+#define G_TYPED_KERNEL_M G_TYPED_KERNEL
 
 #define G_API_OP   G_TYPED_KERNEL
-#define G_API_OP_M G_TYPED_KERNEL_M
+#define G_API_OP_M G_API_OP
 
 namespace cv
 {

modules/gapi/include/opencv2/gapi/infer.hpp

@@ -23,23 +23,6 @@
 
 namespace cv {
 
-namespace detail {
-    // This tiny class eliminates the semantic difference between
-    // GKernelType and GKernelTypeM.
-    // FIXME: Something similar can be reused for regular kernels
-    template<typename, typename>
-    struct KernelTypeMedium;
-
-    template<class K, typename... R, typename... Args>
-    struct KernelTypeMedium<K, std::function<std::tuple<R...>(Args...)> >:
-        public GKernelTypeM<K, std::function<std::tuple<R...>(Args...)> > {};
-
-    template<class K, typename R, typename... Args>
-    struct KernelTypeMedium<K, std::function<R(Args...)> >:
-        public GKernelType<K, std::function<R(Args...)> > {};
-
-} // namespace detail
-
 template<typename, typename> class GNetworkType;
 
 // TODO: maybe tuple_wrap_helper from util.hpp may help with this.