Singleton. Breaks horribly when part of a library and is used in an compilation unit that generates code linked into another binary/library. Source: Raynes singleton system breaking horribly on Windows.

My favourite. Should be easy to guess, but can someone point out the beauty of this snippet?
Code:
_titleLabel->SetFrame([&]() -> RN::Rect {
	RN::Rect rect = _titleLabel->GetFrame();
	
	rect.x = 5.0f;
	rect.y = 5.0f;
	
	return rect;
}());

Shitlord by trade and passion. Graphics programmer at Laminar Research.
I write blog posts at feresignum.com