digitalmars.D.bugs - [Issue 9340] New: Covariant return type conflicts with out contract.
- d-bugmail puremagic.com (43/43) Jan 17 2013 http://d.puremagic.com/issues/show_bug.cgi?id=9340
- d-bugmail puremagic.com (11/11) Jul 18 2013 http://d.puremagic.com/issues/show_bug.cgi?id=9340
http://d.puremagic.com/issues/show_bug.cgi?id=9340 Summary: Covariant return type conflicts with out contract. Product: D Version: D2 Platform: All OS/Version: All Status: NEW Severity: major Priority: P2 Component: DMD AssignedTo: nobody puremagic.com ReportedBy: epi atari8.info The following test case fails to compile with the following error message: test.d(21): Error: cast(const(BaseBar))__result is not an lvalue Comment out line (1) or change ConcreteBar to BaseBar in (2) and it compiles. That means the workaround is to use base type in the overriding method. import std.stdio; class BaseBar { abstract string bar(); } class BaseFoo { abstract BaseBar createBar() out(result) { assert(result !is null); } body { assert(false); } // (1) } class ConcreteBar : BaseBar { override string bar() { return "ConcreteBar"; } } class ConcreteFoo : BaseFoo { override ConcreteBar createBar() { return new ConcreteBar(); } // (2) } void main() { auto foo = new ConcreteFoo(); writeln(foo.createBar().bar()); } -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Jan 17 2013
http://d.puremagic.com/issues/show_bug.cgi?id=9340 Kenji Hara <k.hara.pg gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |DUPLICATE *** This issue has been marked as a duplicate of issue 10479 *** -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Jul 18 2013