On Friday, 2 August 2013 at 07:50:28 UTC, Jakob Ovrum wrote:
Places in D that require `string` either do so because they need the immutable guarantee or they do so out of error (e.g. should have used a string of const characters instead). The latter can of course be worked around, but the only *solution* involves fixing the upstream code, so I'll assume we're discussing the former case.
One of the problems is often the return type. For example, readln will return a string, because it is simply more convenient in end user code. The "standard" string format in D is "string", so that's what it returns.
However, if you call readln!(char[]), then you'll the *exact* same string, but of a non-immutable type.
This means that you *can* get the best out of both worlds, at no extra run-time cost. I think more functions should do this.
Without doing this, you face the eternal problem: Should I return a "string", to give my end user more guarantees, when in fact my char array is perfectly mutable, or should I return a char[], forcing my end user to make an idup(or an unsafe cast) if he actually needed a string?
It's a tough problem to tackle.
