Merge pull request #15955 from VadimLevin:dev/vlevin/generator_tests

Tests for argument conversion of Python bindings generator

* Tests for parsing elemental types from Python bindings

  - Add positive and negative tests for int, float, double, size_t,
    const char*, bool.
  - Tests with wrong conversion behavior are skipped.

* Move implicit conversion of bool to integer/floating types to wrong
conversion behavior.

modules/core/include/opencv2/core/bindings_utils.hpp

@@ -20,6 +20,44 @@ CV_EXPORTS_W String dumpInputOutputArray(InputOutputArray argument);
 
 CV_EXPORTS_W String dumpInputOutputArrayOfArrays(InputOutputArrayOfArrays argument);
 
+CV_WRAP static inline
+String dumpBool(bool argument)
+{
+    return (argument) ? String("Bool: True") : String("Bool: False");
+}
+
+CV_WRAP static inline
+String dumpInt(int argument)
+{
+    return cv::format("Int: %d", argument);
+}
+
+CV_WRAP static inline
+String dumpSizeT(size_t argument)
+{
+    std::ostringstream oss("size_t: ", std::ios::ate);
+    oss << argument;
+    return oss.str();
+}
+
+CV_WRAP static inline
+String dumpFloat(float argument)
+{
+    return cv::format("Float: %.2f", argument);
+}
+
+CV_WRAP static inline
+String dumpDouble(double argument)
+{
+    return cv::format("Double: %.2f", argument);
+}
+
+CV_WRAP static inline
+String dumpCString(const char* argument)
+{
+    return cv::format("String: %s", argument);
+}
+
 CV_WRAP static inline
 AsyncArray testAsyncArray(InputArray argument)
 {