On 10/02/2015 08:15 AM, Per Nordlöw wrote:
On Friday, 2 October 2015 at 11:19:51 UTC, Andrei Alexandrescu wrote:
assert(e1 == e2)
could be lowered into:
{
auto a = e1, b = e2;
if (a == b) return;
onAssertFailed!"=="(a, b, __FILE__, __LINE__, __FUNCTION__,
__MODULE__);
}()
So lowering is kind of like macro expansion for AST-nodes, then?
Not sure what you mean. The code up there will be replaced with the code
down there :o).
Is DMD clever enough to avoid trigger postblits for
auto a = e1, b = e2;
if (a == b) return;
? Or is that part of the question whether this will work?
Ah, interesting. There is a means in the compiler to generate ref
variables, which is not accessible for user code. But perhaps that's not
necessary if we do the lowering as such:
(auto ref a, auto ref b) {
if (a == b) return;
onAssertFailed!"=="(a, b, __FILE__, __LINE__, __FUNCTION__, __MODULE__);
}(e1, e2)
So that evaluates the two expressions and avoids creating copies for
lvalues.
I guess we only need on symbol name for `onAssertFailed` then instead of
`assertBinOp` and `assertUnOp`, right?
Probably a judgment call. I'd start with one and see what happens.
Andrei
