float has too much precision

[Faux Amis via Digitalmars-d-learn]

I'm dumbfounded, why does the following code write '35' on DMD32 D 
Compiler v2.091.0-dirty?

module magic;
float magic( float f )
{
    return f + 35f - f;
}

void main()
{
    import std.stdio;
    writeln( magic(1_000_000_000f) );
}