How will std.allocator change how we program in D?

[Taylor Hillegeist via Digitalmars-d-learn]

I do not come from a c++ background. but have looked at what 
allocators do for c++. I know in D the standard for memory 
management is garbage collection and if we want to manage it 
ourselfs we have to do things like @nogc. I was just curious how 
the std allocator will change how we do things.