[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 --- Comment #12 from github-bugzi...@puremagic.com 2013-07-04 03:03:45 PDT --- Commits pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/877e7bfd7c29fb016323934bb04bd3420bffe5c7 Default args and arg identifiers are now volatile information in TypeFunction. 1. The extra informations would be kept after semantic analysis for function pointer and delegate types. But merging type would strip all the extras from the type structure, then cache the stripped copy into. 2. The types has extra informations cannot be named. In other words, AliasDeclaration would always strip the aliased type. This rule also works for Template Type Parameter, and fixes issue 3646 well. 3. CondExp would strip them from the type of its result. https://github.com/D-Programming-Language/dmd/commit/bce2d07d6cd2c09a5153afc65260b63c32447ade fix Issue 3646 - Default values of function arguments are ignored when instantiating a template. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 Kenji Hara k.hara...@gmail.com changed: What|Removed |Added Status|NEW |RESOLVED Version|D1 D2 |D2 Resolution||FIXED --- Comment #13 from Kenji Hara k.hara...@gmail.com 2013-07-04 04:51:50 PDT --- Right now, default argument is changed to not part of function type in D2. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 Kenji Hara k.hara...@gmail.com changed: What|Removed |Added Keywords||pull --- Comment #11 from Kenji Hara k.hara...@gmail.com 2012-09-05 18:53:52 PDT --- D2 pull: https://github.com/D-Programming-Language/dmd/pull/1102 -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 Jonathan M Davis jmdavisp...@gmx.com changed: What|Removed |Added CC||pun...@coverify.org --- Comment #10 from Jonathan M Davis jmdavisp...@gmx.com 2012-07-02 08:34:37 PDT --- *** Issue 8336 has been marked as a duplicate of this issue. *** -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 Mike Parker aldac...@gmail.com changed: What|Removed |Added CC||aldac...@gmail.com Version|D1 D2 |D2 Severity|normal |regression -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 Mike Parker aldac...@gmail.com changed: What|Removed |Added Version|D2 |D1 D2 Severity|regression |normal --- Comment #9 from Mike Parker aldac...@gmail.com 2012-06-17 22:02:35 PDT --- Somehow I managed to change the settings on the wrong bug. Sorry for the noise. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 yebblies yebbl...@gmail.com changed: What|Removed |Added AssignedTo|nob...@puremagic.com|yebbl...@gmail.com --- Comment #8 from yebblies yebbl...@gmail.com 2012-02-12 13:57:19 EST --- This has the same causes (and same solutions) as issue 3866. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 yebblies yebbl...@gmail.com changed: What|Removed |Added CC||ellery-newco...@utulsa.edu --- Comment #5 from yebblies yebbl...@gmail.com 2011-07-03 22:23:21 EST --- *** Issue 5456 has been marked as a duplicate of this issue. *** -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 yebblies yebbl...@gmail.com changed: What|Removed |Added CC||nfx...@gmail.com --- Comment #4 from yebblies yebbl...@gmail.com 2011-07-03 22:22:51 EST --- *** Issue 4028 has been marked as a duplicate of this issue. *** -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 yebblies yebbl...@gmail.com changed: What|Removed |Added Keywords||patch CC||yebbl...@gmail.com Platform|Other |All --- Comment #6 from yebblies yebbl...@gmail.com 2011-07-03 23:14:09 EST --- https://github.com/D-Programming-Language/dmd/pull/204 -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646
--- Comment #7 from Stewart Gordon s...@iname.com 2011-07-03 08:42:20 PDT ---
(In reply to comment #1)
Not lets see how foo!(bar) looks like after a rewrite:
void foo(Fn)(Fn fn)
{
fn(22);
}
Actually, before this rewrite comes substituting in the template argument.
void fooInstance(void function(int = 22) fn)
{
fn();
}
which then becomes
void fooInstance(void function(int) fn)
{
fn(22);
}
Now there is no wonder why dmd behaves like this.
But it makes sense only if there are actually two template instances involved.
The essence of the bug is that, after it has instantiated foo with argument
void function(int = 22), the compiler matches any attempt to instantiate foo
with a void function(int), with or without a default argument, to this
instance.
(In reply to comment #2)
Yeah, that was pretty much what I was thinking about. The issue
cuts down to a question, should Foo be instantiated once or are the
function types equal? For binary size and efficiency purposes I
agree that there should be one instantiation. On the other hand
for meta programming and code generation which is what I am doing I
would like to have them as separate types, as I don't want to loose
this information. Walter or Andrei would probably have to comment
on this issue.
But this seems to me a rare use case. And you can do it with an alias template
parameter, though this does create a separate instance for each function name:
--
import std.stdio;
void foo(alias fn)() {
fn();
fn(42);
}
void bar(int i = 22) {
writefln(bar %d, i);
}
void bam(int i) {
writefln(bam %d, i);
}
void quux() {
writefln(quux);
}
void quux(int i) {
writefln(quux %d, i);
}
void main() {
foo!(bar)();// works
//foo!(bam)(); // correctly triggers compiler error (1.068 Win32)
foo!(quux)(); // works with overloads as well
}
--
I can see three possible ways to resolve this issue:
(a) Default arguments aren't part of the function type. Then only one template
instance exists: foo!(void function(int)). The template instance is then
illegal, since it tries to call a void function(int) with no arguments.
(b) Default arguments are part of the function type. Then there are two
template instances:
foo(bar) is foo!(void function(int = 22))
foo(bam) is foo!(void function(int))
Then foo(bar) is legal: foo(bar)() calls bar(22)
and foo(bam) is illegal
(c) Default arguments are part of the function type, but can be optimised away.
Essentially, we detect while instantiating the template whether the template
body makes use of a default argument. If so, create a separate instance for
each default argument or absence thereof. Otherwise, create only one instance.
Not sure whether this is desirable.
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[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646
Stewart Gordon s...@iname.com changed:
What|Removed |Added
Keywords||accepts-invalid, spec
CC||s...@iname.com
Version|2.035 |1.051
Blocks||340
OS/Version|Linux |All
--- Comment #3 from Stewart Gordon s...@iname.com 2010-01-03 08:53:39 PST ---
I've never heard of default arguments being part of the function type's
properties. I'd probably guessed that the type is simply void function(int)
but default arguments are filled in on the caller side. In which case the
functions are the same type, and so this isn't meant to work. Either way, it's
certainly a bug that the code is accepted.
And it applies to D1 too, but the code needs changing a bit:
--
import std.stdio;
void foo(Fn)(Fn fn) {
fn();
}
void bar(int i = 22) {
writefln(bar , i);
}
void bam(int i) {
writefln(bam , i);
}
void main() {
foo(bar);
foo(bam);
}
--
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[Issue 3646] Default values of function arguments are ignored when instantiating a template.
http://d.puremagic.com/issues/show_bug.cgi?id=3646 --- Comment #2 from Eldar Insafutdinov e.insafutdi...@gmail.com 2009-12-26 12:51:57 PST --- (In reply to comment #1) This is a bit more tricky than it looks like. The question here is, how many times should foo be instanciated? DMD answers just 1 time, and I agree with it, since bar and bam have same signature and mangling. But this only happens if foo!(bar) is instanciated before foo!(bam), because when templates are instantiates on first use. When you instanciate foo!(bam) first, it doesn't get rewritten and therefore fails to compile. I guess the only fix for this issue would be to create an implicit trampoline to invoke functions with default arguments, but only Walter can say for sure. Yeah, that was pretty much what I was thinking about. The issue cuts down to a question, should Foo be instantiated once or are the function types equal? For binary size and efficiency purposes I agree that there should be one instantiation. On the other hand for meta programming and code generation which is what I am doing I would like to have them as separate types, as I don't want to loose this information. Walter or Andrei would probably have to comment on this issue. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
