core: use "explicit" for Matx() ctor

modules/core/include/opencv2/core/matx.hpp

@@ -66,13 +66,14 @@ namespace cv
 ////////////////////////////// Small Matrix ///////////////////////////
 
 //! @cond IGNORED
-struct CV_EXPORTS Matx_AddOp {};
-struct CV_EXPORTS Matx_SubOp {};
-struct CV_EXPORTS Matx_ScaleOp {};
-struct CV_EXPORTS Matx_MulOp {};
-struct CV_EXPORTS Matx_DivOp {};
-struct CV_EXPORTS Matx_MatMulOp {};
-struct CV_EXPORTS Matx_TOp {};
+// FIXIT Remove this (especially CV_EXPORTS modifier)
+struct CV_EXPORTS Matx_AddOp { Matx_AddOp() {} Matx_AddOp(const Matx_AddOp&) {} };
+struct CV_EXPORTS Matx_SubOp { Matx_SubOp() {} Matx_SubOp(const Matx_SubOp&) {} };
+struct CV_EXPORTS Matx_ScaleOp { Matx_ScaleOp() {} Matx_ScaleOp(const Matx_ScaleOp&) {} };
+struct CV_EXPORTS Matx_MulOp { Matx_MulOp() {} Matx_MulOp(const Matx_MulOp&) {} };
+struct CV_EXPORTS Matx_DivOp { Matx_DivOp() {} Matx_DivOp(const Matx_DivOp&) {} };
+struct CV_EXPORTS Matx_MatMulOp { Matx_MatMulOp() {} Matx_MatMulOp(const Matx_MatMulOp&) {} };
+struct CV_EXPORTS Matx_TOp { Matx_TOp() {} Matx_TOp(const Matx_TOp&) {} };
 //! @endcond
 
 /** @brief Template class for small matrices whose type and size are known at compilation time
@@ -118,7 +119,7 @@ public:
     //! default constructor
     Matx();
 
-    Matx(_Tp v0); //!< 1x1 matrix
+    explicit Matx(_Tp v0); //!< 1x1 matrix
     Matx(_Tp v0, _Tp v1); //!< 1x2 or 2x1 matrix
     Matx(_Tp v0, _Tp v1, _Tp v2); //!< 1x3 or 3x1 matrix
     Matx(_Tp v0, _Tp v1, _Tp v2, _Tp v3); //!< 1x4, 2x2 or 4x1 matrix

modules/core/test/test_operations.cpp

@@ -794,13 +794,13 @@ bool CV_OperationsTest::TestTemplateMat()
 
         Size size(2, 5);
         TestType<float>(size, 1.f);
-        cv::Vec3f val1 = 1.f;
+        cv::Vec3f val1(1.f);
         TestType<cv::Vec3f>(size, val1);
-        cv::Matx31f val2 = 1.f;
+        cv::Matx31f val2(1.f);
         TestType<cv::Matx31f>(size, val2);
-        cv::Matx41f val3 = 1.f;
+        cv::Matx41f val3(1.f);
         TestType<cv::Matx41f>(size, val3);
-        cv::Matx32f val4 = 1.f;
+        cv::Matx32f val4(1.f);
         TestType<cv::Matx32f>(size, val4);
     }
     catch (const test_excep& e)