On 2/16/18 8:16 AM, bauss wrote:
On Friday, 16 February 2018 at 13:08:09 UTC, bauss wrote:
On Friday, 16 February 2018 at 12:15:07 UTC, arturg wrote:
On Friday, 16 February 2018 at 11:45:21 UTC, arturg wrote:
this code fails to compile:
void delegate(void*) dg;
void delegate(void*)[] dgs = [dg, dg, dg];
dgs.writeln;
dgs.remove(1).writeln();
if you comment out dgs.writeln; it works as expected,
it works if you use other types then void*:
void delegate(int*) dg;
void delegate(int*)[] dgs = [dg, dg, dg];
dgs.writeln;
dgs.remove(1).writeln();
the compiler is DMD64 D Compiler v2.078.2 and the error message is:
/usr/include/dlang/dmd/std/algorithm/mutation.d(1929): Error:
template std.algorithm.mutation.moveAll cannot deduce function from
argument types !()(void delegate(void*)[], void delegate(void*)[]),
candidates are:
/usr/include/dlang/dmd/std/algorithm/mutation.d(1455):
std.algorithm.mutation.moveAll(InputRange1, InputRange2)(InputRange1
src, InputRange2 tgt) if (isInputRange!InputRange1 &&
isInputRange!InputRange2 && is(typeof(move(src.front, tgt.front))))
empty.d(9): Error: template instance
std.algorithm.mutation.remove!(cast(SwapStrategy)2, void
delegate(void*)[], int) error instantiating
running all dmd version on run.dlang.io
gives me this output:
Up to 2.075.1: Success with output:
-----
[void delegate(void*), void delegate(void*), void delegate(void*)]
[void delegate(void*), void delegate(void*)]
-----
Since 2.076.1: Failure with output:
-----
/path/to/dmd.linux/dmd2/linux/bin64/../../src/phobos/std/algorithm/mutation.d(1929):
Error: template std.algorithm.mutation.moveAll cannot deduce function
from argument types !()(void delegate(void*)[], void
delegate(void*)[]), candidates are:
/path/to/dmd.linux/dmd2/linux/bin64/../../src/phobos/std/algorithm/mutation.d(1455):
std.algorithm.mutation.moveAll(InputRange1, InputRange2)(InputRange1
src, InputRange2 tgt) if (isInputRange!InputRange1 &&
isInputRange!InputRange2 && is(typeof(move(src.front, tgt.front))))
onlineapp.d(7): Error: template instance
std.algorithm.mutation.remove!(cast(SwapStrategy)2, void
delegate(void*)[], int) error instantiating
-----
It's definitely a bug, the question is what change has caused it.
Looking at "moveAll" which is the one that causes the error, no changes
has been made to that which could cause this as within the last 3 months
only changes made to it has been two asserts that has been inserted.
Other than that has only been a documentation change a year ago and
prior to that changes hasn't been made to it for 3 years.
So it's a bug in the compiler, rather than Phobos itself.
Strictly speaking, this is not necessarily proof that it's in phobos,
there could have been changes elsewhere that cause one of the conditions
to fail.
However, testing this out, I found something very weird.
If you pragma(msg, isInputRange!(typeof(dgs))); inside your file, then
it compiles (and prints true for that pragma).
Makes no sense at all. Definitely seems like a compiler bug. A
pragma(msg) shouldn't affect the outcome.
-Steve
