在stl和.net基本库默认搜索中使用哪种排序算法？

I am now working on an imprived version of merge sort. I implemented it with C++ and C#. Then compared them with the stl sort and array.sort() algorithm respectively. In C++ I have got an equal (sometimes better) result. But in C#, I had to use unsafe code for using pointers. Here the performence is not that much comparable with default sort. So, I want to know-I am now working on an imprived version of merg