assert(obj) is an atrocity
dawg at dawgfoto.de
Tue Nov 8 16:18:38 PST 2011
On Tue, 08 Nov 2011 23:35:33 +0100, Alex Rønne Petersen
<xtzgzorex at gmail.com> wrote:
> As the title suggests, I'm going to be rather blunt about this.
> assert(obj) testing the invariant *without* doing a null check is insane
> for the following reasons:
> 1) It is not what a user expects. It is *unintuitive*.
> 2) assert(!obj) does an is-null check. assert(obj) is a completely
> broken opposite of this.
> 3) No AssertError is thrown, which is the entire point of the built-in
> 4) The few added instructions for the null check hardly matter in a
> *debug* build of all things.
> I don't mind assert(obj) testing the invariant of obj. In fact, that
> very much makes sense. But please, please, *please* check the object for
> null first. This is a random inconsistency in the language with no other
> justification than "seg faults are convenient in a debugger". By the
> same logic, we might as well not have array bounds checks. However, the
> state of things is that array bounds checks are emitted by default and
> users can disable them for e.g. a release build. I don't see why this
> case is any different.
> - Alex
It does check for null.
Only it's a runtime support function (_d_invariant) and druntime is likely
compiled without assertions. Are you really suggesting to add a null check
every method call?
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