On 4/15/16 4:05 PM, Andrei Alexandrescu wrote:
On 04/15/2016 03:13 PM, Steven Schveighoffer wrote:
On 4/15/16 2:48 PM, Andrei Alexandrescu wrote:
On 4/15/16 2:46 PM, Steven Schveighoffer wrote:
inout(T)[] overlap(T)(inout(T)[] r1, inout(T)[] r2) @trusted pure
nothrow
{
import std.algorithm: min, max;
auto b = max(r1.ptr, r2.ptr);
auto e = min(r1.ptr + r1.length, r2.ptr + r2.length);
return b < e ? b[0 .. e - b] : null;
}
Is that better or worse than the one without inout? -- Andrei
Better. It generates one implementation for all 9 combinations of
mutability. Yours generates 9 identical binary functions.
A valid but weak argument. There's been long talk about eliminating
binary identical functions in the front end (some linkers already do
it). That would be the real solution that would help cases unrelated to
inout, too.
The main argument is this:
auto overlap(T, U)(T[] r1, U[] r2) @trusted pure nothrow
Can you tell, does overlap modify any data in r1 or r2?
If you find such advertisement useless, you of course do not need inout
or const.
And yours possibly depends on a bug:
https://issues.dlang.org/show_bug.cgi?id=15930
Red herring. Fixing the bug shouldn't break that code.
I don't know what the bug is. That's why I said "possibly." I was
surprised your code compiled with both const/mutable parameters, but
then I found the bug. It's possible it could be fixed and become
correct. I'm not sure.
-Steve
