type * ptr = stackalloc type [ expr ];

// cs_keyword_stackalloc.cs
// compile with: /unsafe
using System;
class Test
{
    static unsafe void Main()
    {
        int* fib = stackalloc int[100];
        int* p = fib;
        *p++ = *p++ = 1;
        for (int i = 2; i < 100; ++i, ++p)
        {
            *p = p[-1] + p[-2];
        }
        for (int i = 0; i < 10; ++i)
        {
            Console.WriteLine(fib[i]);
        }
    }
}