cmake: update CXX11 compiler flag

cmake/OpenCVDetectCXXCompiler.cmake

@@ -182,3 +182,23 @@ if(CMAKE_VERSION VERSION_LESS "3.1")
     endif()
   endforeach()
 endif()
+
+if(ENABLE_CXX11)
+  #cmake_minimum_required(VERSION 3.1.0 FATAL_ERROR)
+  set(CMAKE_CXX_STANDARD 11)
+  set(CMAKE_CXX_STANDARD_REQUIRED TRUE)
+  set(CMAKE_CXX_EXTENSIONS OFF) # use -std=c++11 instead of -std=gnu++11
+  if(XCMAKE_CXX11_COMPILE_FEATURES)
+    set(HAVE_CXX11 ON)
+  endif()
+endif()
+if(NOT HAVE_CXX11)
+  ocv_check_compiler_flag(CXX "" HAVE_CXX11 "${OpenCV_SOURCE_DIR}/cmake/checks/cxx11.cpp")
+  if(NOT HAVE_CXX11 AND ENABLE_CXX11)
+    ocv_check_compiler_flag(CXX "-std=c++11" HAVE_STD_CXX11 "${OpenCV_SOURCE_DIR}/cmake/checks/cxx11.cpp")
+    if(HAVE_STD_CXX11)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+      set(HAVE_CXX11 ON)
+    endif()
+  endif()
+endif()

cmake/checks/cxx11.cpp

@@ -0,0 +1,13 @@
+#if __cplusplus >= 201103L || (defined(_MSC_VER) && _MSC_VER >= 1600)
+// OK
+#else
+#error "C++11 is not supported"
+#endif
+
+static int test() { return 0; }
+
+int main()
+{
+    auto res = test();
+    return res;
+}