Checking function parameters in Phobos

[Meta]

On Monday, 25 November 2013 at 07:24:10 UTC, Meta wrote:
> 	auto a = validated!containsFortyTwo(new FortyTwo());
> 	auto b = a;
> 	//Passes
> 	assert(a.i == 42);
> 	assert(b.i == 42);
> 	mutateFortyTwo(a);
> 	//Fails
> 	assert(a.i == 43);
> 	assert(b.i == 43);

"//Fails" should be "//Passes" as well.