fast way to insert element at index 0

[Assembly via Digitalmars-d-learn]

What's a fast way to insert an element at index 0 of array? now 
that the code is working I want to clean this:

void push(T val)
        {
                T[] t = new T[buffer.length + 1];
                t[0] = val;
                t[1 .. $] = buffer;
                buffer = t;
        }
I did this because I didn't find any suble built-in data 
structure that let me insert an item into a specific index at 
first search. Slist does have insertFron(), exactly what I'm 
looking for it's a linked list.