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March 16, 2012 [Issue 7717] New: Regression(2.059): typeof(this) incorrect in mixin template | ||||
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http://d.puremagic.com/issues/show_bug.cgi?id=7717 Summary: Regression(2.059): typeof(this) incorrect in mixin template Product: D Version: D2 Platform: All OS/Version: All Status: NEW Severity: regression Priority: P2 Component: DMD AssignedTo: nobody@puremagic.com ReportedBy: thecybershadow@gmail.com --- Comment #0 from Vladimir Panteleev <thecybershadow@gmail.com> 2012-03-15 17:05:19 PDT --- template IsValid(T) { enum IsValid = is(typeof(T.init.x)); } mixin template T() { static assert(IsValid!(typeof(this))); } struct S { int x; mixin T; } The IsValid template is not necessary to reproduce the problem - it's for illustration. This also fails: static assert(is(typeof(typeof(this).init.x))); But not this: static assert(is(typeof(x))); -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
March 16, 2012 [Issue 7717] Regression(2.059): typeof(this) incorrect in mixin template | ||||
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Posted in reply to Vladimir Panteleev | http://d.puremagic.com/issues/show_bug.cgi?id=7717 Don <clugdbug@yahoo.com.au> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |clugdbug@yahoo.com.au --- Comment #1 from Don <clugdbug@yahoo.com.au> 2012-03-16 01:36:31 PDT --- It's not clear that there's a bug here. typeof(this).init correctly shouldn't compile inside a mixin, because the mixin might add an extra field -- so then init would change. .init is defined only when all possible members of the aggregate have been declared. Can you come up with a valid example? -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
March 16, 2012 [Issue 7717] Regression(2.059): typeof(this) incorrect in mixin template | ||||
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Posted in reply to Vladimir Panteleev | http://d.puremagic.com/issues/show_bug.cgi?id=7717 timon.gehr@gmx.ch changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |timon.gehr@gmx.ch --- Comment #2 from timon.gehr@gmx.ch 2012-03-16 03:08:17 PDT --- (In reply to comment #1) > It's not clear that there's a bug here. typeof(this).init correctly shouldn't compile inside a mixin, because the mixin might add an extra field It does not add an extra field. > -- so then init would change. If I added some random character to a valid d program, then it would likely not be valid anymore. What does this prove? > > .init is defined only when all possible members of the aggregate have been declared. This is the case in the example. What should be illegal is adding a field that changes .init based on a static condition that depends on .init. This would be part of a necessary general overhaul of symbol lookup works in DMD: Forward declarations and compile-time reflection make it possible to write contradictory or ambiguous D programs. The compiler should detect such setups in the least conservative way we can come up with. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
March 16, 2012 [Issue 7717] Regression(2.059): typeof(this) incorrect in mixin template | ||||
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Posted in reply to Vladimir Panteleev | http://d.puremagic.com/issues/show_bug.cgi?id=7717 --- Comment #3 from Vladimir Panteleev <thecybershadow@gmail.com> 2012-03-16 08:44:28 PDT --- If this behavior is invalid by design, then the error message should be improved (e.g. to ".init not known at this point" or "recursive semantic analysis attempt on S"). The workaround is to use std.traits.hasMember (which, underneath, uses __traits(allMembers, T)). -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
March 16, 2012 [Issue 7717] Regression(2.059): typeof(this) incorrect in mixin template | ||||
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Posted in reply to Vladimir Panteleev | http://d.puremagic.com/issues/show_bug.cgi?id=7717 --- Comment #4 from Vladimir Panteleev <thecybershadow@gmail.com> 2012-03-16 09:03:39 PDT --- > then the error message should be improved Never mind, the check is inside an is() condition - so AFAIU any errors should be silenced. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
March 17, 2012 [Issue 7717] Regression(2.059): typeof(this) incorrect in mixin template | ||||
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Posted in reply to Vladimir Panteleev | http://d.puremagic.com/issues/show_bug.cgi?id=7717 --- Comment #5 from Don <clugdbug@yahoo.com.au> 2012-03-16 23:47:01 PDT --- (In reply to comment #2) > (In reply to comment #1) > > It's not clear that there's a bug here. typeof(this).init correctly shouldn't compile inside a mixin, because the mixin might add an extra field > > It does not add an extra field. > > > -- so then init would change. > > If I added some random character to a valid d program, then it would likely not be valid anymore. What does this prove? The point is that accessing .init from inside a mixin is not valid in the general case. Although in this specific example, it could be made to work, that isn't true in general. Likewise, .sizeof is not defined until all declarations have been run. > > .init is defined only when all possible members of the aggregate have been declared. > > This is the case in the example. What should be illegal is adding a field that changes .init based on a static condition that depends on .init. This would be part of a necessary general overhaul of symbol lookup works in DMD: Forward declarations and compile-time reflection make it possible to write contradictory or ambiguous D programs. The compiler should detect such setups in the least conservative way we can come up with. OK. That's clearly an enhancement request. Compiler is working as designed. This only seemed to compile before, because of a compiler bug. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
April 02, 2012 [Issue 7717] Regression(2.059): typeof(this) incorrect in mixin template | ||||
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Posted in reply to Vladimir Panteleev | http://d.puremagic.com/issues/show_bug.cgi?id=7717 --- Comment #6 from Don <clugdbug@yahoo.com.au> 2012-04-02 04:54:08 PDT --- The change in behaviour is probaby related to the fixes for bug 3509 and bug 3510. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
April 06, 2012 [Issue 7717] Regression(2.059): typeof(this) incorrect in mixin template | ||||
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Posted in reply to Vladimir Panteleev | http://d.puremagic.com/issues/show_bug.cgi?id=7717 Walter Bright <bugzilla@digitalmars.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |bugzilla@digitalmars.com Severity|regression |enhancement -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
January 13, 2013 [Issue 7717] Regression(2.059): typeof(this) incorrect in mixin template | ||||
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Posted in reply to Vladimir Panteleev | http://d.puremagic.com/issues/show_bug.cgi?id=7717 Andrej Mitrovic <andrej.mitrovich@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |andrej.mitrovich@gmail.com --- Comment #7 from Andrej Mitrovic <andrej.mitrovich@gmail.com> 2013-01-12 20:22:27 PST --- Status in 2.061: The OP sample works, however: > This also fails: > static assert(is(typeof(typeof(this).init.x))); > But not this: > static assert(is(typeof(x))); Both of these fail now. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
January 13, 2013 [Issue 7717] Regression(2.059): typeof(this) incorrect in mixin template | ||||
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Posted in reply to Vladimir Panteleev | http://d.puremagic.com/issues/show_bug.cgi?id=7717 Vladimir Panteleev <thecybershadow@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |WORKSFORME --- Comment #8 from Vladimir Panteleev <thecybershadow@gmail.com> 2013-01-13 06:37:26 EET --- (In reply to comment #7) > Both of these fail now. Those assert lines should be placed instead of the assert line in the example code. All of the cases presented seem to work in DMD 2.061. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
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