C#就地修改字符串

今天讨论字符串问题讨论到字符串存储问题，想到通过就地修改字符串验证写死的字符串是否存储在同一位置的问题，在MSDN找到以下代码：

class UnsafeString
{
    unsafe static void Main(string[] args)
    {
        // Compiler will store (intern) 
        // these strings in same location.
        string s1 = "Hello";
        string s2 = "Hello";

        // Change one string using unsafe code.
        fixed (char* p = s1)
        {
            p[0] = 'C';
        }

        //  Both strings have changed.
        Console.WriteLine(s1);
        Console.WriteLine(s2);

        // Keep console window open in debug mode.
        Console.WriteLine("Press any key to exit.");
        Console.ReadKey();
    }

}

详情参考：https://msdn.microsoft.com/zh-cn/library/ms228599.aspx