why >?= and <?= don't work in VC++?

c++

Solution

Because those are the old GC++-specific extensions for minimum and maximum.

From 6. Extensions to the C++ Language:

The GNU compiler provides these extensions to the C++ language (and you can also use most of the C language extensions in your C++ programs). If you want to write code that checks whether these features are available, you can test for the GNU compiler the same way as for C programs: check for a predefined macro `__GNUC__`. You can also use `__GNUG__` to test specifically for GNU C++ (see section 'Predefined Macros' in The GNU C Preprocessor).

- 6.1 Minimum and Maximum Operators in C++ C++ Minimum and maximum operators.

- ...

Instead, you should use `std::min` and `std::max`.

Problem

Original source