Use LLVM OStream wrapper instead of <iostream> in the logger. llvm::OStream provides all std::ostream functionality (by holding a std::ostream* internally), but * doesn't include <iostream>, avoiding per-file overhead. * allows the stream pointer to be null, and the (inlined) operators do nothing when that's the case. (This also allows removal of the ofstream("/dev/null") hack Logger used when disabled, which presumably wasn't very portable)

module sdldemo1;
import sdl;
void main()
{
    auto disp = SDL_SetVideoMode(640,480,0,SDL_HWSURFACE|SDL_DOUBLEBUF);
    auto r = SDL_Rect(0,190,100,100);
    auto c = SDL_MapRGBA(disp.format,255,100,0,255);
    while (r.x < disp.w-100) {
        SDL_FillRect(disp, null, 0);
        SDL_FillRect(disp, &r, c);
        SDL_Flip(disp);
        r.x++;
    }
}