http://d.puremagic.com/issues/show_bug.cgi?id=7355
--- Comment #6 from timon.g...@gmx.ch 2012-01-26 09:55:37 PST --- (In reply to comment #5) > (In reply to comment #3) > > > The typeof resolves to error because inout resolves to immutable. > > As I said, it should fail to match or match mutable and fail to call. I'm not > sure which is correct, but I feel either way that the assert should fail. If > it's resolving to immutable, I think it's a bug, not because it's not passing, > but because it's failing for the wrong reason. > > I think your expectations would be a violation of const. No. > Let's assume inout > did resolve to const for foo, and the function could be called: > > immutable int x = 5; > immutable(int)* xp = &x; > immutable(int)** xpp = &xp; > > const(int *)* y = foo(xpp); > > int z = 2; > > *y = &z; // this should pass, since I can assign int* to const(int*). You cannot assign anything to const(int*), that is the point of const. > > assert(*xp == 2); > z = 3; > assert(*xp == 3); // oops! changed data perceived as immutable! > > Is there an error in my example? I think it comes down to this: > > immutable(int *)* foo(immutable(int *)* x) // inout == immutable > const(int *)* foo( const(int *)* x) // inout == const > int ** foo( int ** x) // inout == mutable > > none of these can be called with immutable(int)** because there is no implicit > cast to the parameter. I don't think const(immutable(int)*)* reduces to > const(int *)*. It does. The second version is callable with immutable(int)**. Not fixing this would mean there are cases where code duplication is more expressive than inout. > > This does take some mental effort, so I may have made a mistake :) I hate > double pointers... We have: immutable(T) is a subtype of const(T). => immutable(int) :< const(int) const(T*) :< const(S*) iff const(T) :< const(S) => const(immutable(int)*) :< const(int*) const(T)* :< const(S)* iff const(T) :< const(S) => const(immutable(int)*)* : const(int*)* qed -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
