test.d

import std.math;

T[] map(T, V)(T function(T) f, V[] list)
{
    T[] result = new T[](list.length);
    
    foreach(k, v; list)
    {
        result[k] = f(v);
    }
    
    return result;
}

void main()
{
    assert (map!(real, float) (&sqrt, [4.0f, 9.0f]) == [2.0f, 3.0f]);
}