shorthand for literal type annotations?

[jackmott]

I have a vague memory of someone tweeting me a way to avoid having to put a 
type annotation on every field in an array like so:
    
    
    var gradZ = [
        0'f32, 0'f32, 0'f32, 0'f32,
        1'f32, 1'f32,-1'f32,-1'f32,
        1'f32, 1'f32,-1'f32,-1'f32]
    
    

But I can't remember, is there a way?