It seems to be likely that 1.0 will hit before this really holds true. In Beta 6 I'm told you can easily crash the compiler with recursive generic ADTs and most

It seems to be likely that 1.0 will hit before this really holds true. In Beta 6 I'm told you can easily crash the compiler with recursive generic ADTs and most have to travel "through" some heap type to compile at all. Furthermore, Swift doesn't support enough laziness/deferral/coalgebraic formulation to have, say, an infinite stream type without breaking GCD. These will probably be fixed in time, but Swift's ADT support is still pretty experimental to say the least.