Merge pull request #23736 from seanm:c++11-simplifications

Removed all pre-C++11 code, workarounds, and branches #23736

This removes a bunch of pre-C++11 workrarounds that are no longer necessary as C++11 is now required.
It is a nice clean up and simplification.

* No longer unconditionally #include <array> in cvdef.h, include explicitly where needed
* Removed deprecated CV_NODISCARD, already unused in the codebase
* Removed some pre-C++11 workarounds, and simplified some backwards compat defines
* Removed CV_CXX_STD_ARRAY
* Removed CV_CXX_MOVE_SEMANTICS and CV_CXX_MOVE
* Removed all tests of CV_CXX11, now assume it's always true. This allowed removing a lot of dead code.
* Updated some documentation consequently.
* Removed all tests of CV_CXX11, now assume it's always true
* Fixed links.

---------

Co-authored-by: Maksim Shabunin <maksim.shabunin@gmail.com>
Co-authored-by: Alexander Smorkalov <alexander.smorkalov@xperience.ai>

samples/cpp/tutorial_code/core/how_to_use_OpenCV_parallel_for_/how_to_use_OpenCV_parallel_for_.cpp

@@ -2,6 +2,8 @@
 #include <opencv2/core.hpp>
 #include <opencv2/imgcodecs.hpp>
 
+#define PARALLEL_FOR_LAMBDA
+
 using namespace std;
 using namespace cv;
 
@@ -33,6 +35,8 @@ int mandelbrotFormula(const complex<float> &z0, const int maxIter=500) {
 }
 //! [mandelbrot-grayscale-value]
 
+#ifndef PARALLEL_FOR_LAMBDA
+
 //! [mandelbrot-parallel]
 class ParallelMandelbrot : public ParallelLoopBody
 {
@@ -71,6 +75,8 @@ private:
 };
 //! [mandelbrot-parallel]
 
+#endif // !PARALLEL_FOR_LAMBDA
+
 //! [mandelbrot-sequential]
 void sequentialMandelbrot(Mat &img, const float x1, const float y1, const float scaleX, const float scaleY)
 {
@@ -102,7 +108,7 @@ int main()
 
     double t1 = (double) getTickCount();
 
-    #ifdef CV_CXX11
+#ifdef PARALLEL_FOR_LAMBDA
 
     //! [mandelbrot-parallel-call-cxx11]
     parallel_for_(Range(0, mandelbrotImg.rows*mandelbrotImg.cols), [&](const Range& range){
@@ -121,14 +127,14 @@ int main()
     });
     //! [mandelbrot-parallel-call-cxx11]
 
-    #else
+#else // PARALLEL_FOR_LAMBDA
 
     //! [mandelbrot-parallel-call]
     ParallelMandelbrot parallelMandelbrot(mandelbrotImg, x1, y1, scaleX, scaleY);
     parallel_for_(Range(0, mandelbrotImg.rows*mandelbrotImg.cols), parallelMandelbrot);
     //! [mandelbrot-parallel-call]
 
-    #endif
+#endif // PARALLEL_FOR_LAMBDA
 
     t1 = ((double) getTickCount() - t1) / getTickFrequency();
     cout << "Parallel Mandelbrot: " << t1 << " s" << endl;

samples/cpp/tutorial_code/core/how_to_use_OpenCV_parallel_for_/how_to_use_OpenCV_parallel_for_new.cpp

@@ -4,6 +4,8 @@
 #include <opencv2/imgproc.hpp>
 #include <opencv2/highgui.hpp>
 
+#define PARALLEL_FOR_LAMBDA
+
 using namespace std;
 using namespace cv;
 
@@ -47,7 +49,8 @@ void conv_seq(Mat src, Mat &dst, Mat kernel)
 }
 //! [convolution-sequential]
 
-#ifdef CV_CXX11
+#ifdef PARALLEL_FOR_LAMBDA
+
 void conv_parallel(Mat src, Mat &dst, Mat kernel)
 {
     int rows = src.rows, cols = src.cols;
@@ -118,7 +121,8 @@ void conv_parallel_row_split(Mat src, Mat &dst, Mat kernel)
                     });
     //! [convolution-parallel-cxx11-row-split]
 }
-#else
+
+#else // PARALLEL_FOR_LAMBDA
 
 //! [convolution-parallel]
 class parallelConvolution : public ParallelLoopBody
@@ -235,7 +239,7 @@ void conv_parallel_row_split(Mat src, Mat &dst, Mat kernel)
     //! [convolution-parallel-function-row]
 }
 
-#endif
+#endif // PARALLEL_FOR_LAMBDA
 
 static void help(char *progName)
 {
@@ -329,4 +333,4 @@ int main(int argc, char *argv[])
     // imwrite("dst.png", dst);
 
     return 0;
-}
+}

samples/cpp/tutorial_code/core/mat_the_basic_image_container/mat_the_basic_image_container.cpp

@@ -59,12 +59,12 @@ int main(int,char**)
     cout << "C = " << endl << " " << C << endl << endl;
     //! [comma]
     // do the same with initializer_list
-#ifdef CV_CXX11
+
     //! [list]
     C = (Mat_<double>({0, -1, 0, -1, 5, -1, 0, -1, 0})).reshape(3);
     cout << "C = " << endl << " " << C << endl << endl;
     //! [list]
-#endif
+
     //! [clone]
     Mat RowClone = C.row(1).clone();
     cout << "RowClone = " << endl << " " << RowClone << endl << endl;