Merge pull request #8208 from csukuangfj:complex_support

Add support for printing out cv::Complex. (#8208)

* Add support for printing out cv::Complex.

* Conform to the format of std::complex.

* Remove extra spaces.

* Remove extra spaces.

modules/core/include/opencv2/core/cvstd.inl.hpp

@@ -183,6 +183,12 @@ std::ostream& operator << (std::ostream& out, const Mat& mtx)
     return out << Formatter::get()->format(mtx);
 }
 
+template<typename _Tp> static inline
+std::ostream& operator << (std::ostream& out, const Complex<_Tp>& c)
+{
+    return out << "(" << c.re << "," << c.im << ")";
+}
+
 template<typename _Tp> static inline
 std::ostream& operator << (std::ostream& out, const std::vector<Point_<_Tp> >& vec)
 {