[Issue 2625] Creating new struct with literal bypasses immutability of members if struct is in array
https://issues.dlang.org/show_bug.cgi?id=2625 Andrei Alexandrescu and...@erdani.com changed: What|Removed |Added Version|2.023 |D2 --
[Issue 2625] Creating new struct with literal bypasses immutability of members if struct is in array
http://d.puremagic.com/issues/show_bug.cgi?id=2625 Walter Bright bugzi...@digitalmars.com changed: What|Removed |Added Status|NEW |RESOLVED CC||bugzi...@digitalmars.com Resolution||FIXED --- Comment #10 from Walter Bright bugzi...@digitalmars.com 2011-06-11 20:17:30 PDT --- https://github.com/D-Programming-Language/dmd/commit/365297878c11039944be5d78d57909564bef70aa -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 2625] Creating new struct with literal bypasses immutability of members if struct is in array
http://d.puremagic.com/issues/show_bug.cgi?id=2625 --- Comment #9 from Stewart Gordon s...@iname.com 2010-12-07 04:08:05 PST --- A similar problem has just cropped up as issue 5327. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 2625] Creating new struct with literal bypasses immutability of members if struct is in array
http://d.puremagic.com/issues/show_bug.cgi?id=2625 --- Comment #8 from s...@iname.com 2009-04-19 07:59 --- (In reply to comment #7) To me, that's the compiler being correct - quite a different thing from the code being correct. both functions have the same code. That depends on whether you mean source code or object code. I was thinking about source code when I made that statement. --
[Issue 2625] Creating new struct with literal bypasses immutability of members if struct is in array
http://d.puremagic.com/issues/show_bug.cgi?id=2625 --- Comment #6 from s...@iname.com 2009-04-04 08:51 --- (In reply to comment #5) (In reply to comment #3) Where on that page is the issue addressed? see Const and Invariant Structs That bit talks about the whole struct being declared const. But you're right, it doesn't seem to make sense. It would appear that that section had been blindly cp'd from the page about classes, except that that page now doesn't go into as much detail on this matter. I think, broken() is correct, since invariant data can be referenced directly, so it's incorrect for it to change in time. I'm a little puzzled by your use of correct. I meant, it's correct that error is given for broken(). To me, that's the compiler being correct - quite a different thing from the code being correct. --
[Issue 2625] Creating new struct with literal bypasses immutability of members if struct is in array
http://d.puremagic.com/issues/show_bug.cgi?id=2625 --- Comment #7 from ma...@pochta.ru 2009-04-04 09:16 --- (In reply to comment #6) That bit talks about the whole struct being declared const. it talks about members too. I meant, it's correct that error is given for broken(). To me, that's the compiler being correct - quite a different thing from the code being correct. both functions have the same code. --
[Issue 2625] Creating new struct with literal bypasses immutability of members if struct is in array
http://d.puremagic.com/issues/show_bug.cgi?id=2625 --- Comment #4 from s...@iname.com 2009-04-03 09:09 --- Here's how it would have to work. Really, there are four constancy levels: - reassignable (the default) - mutable but non-reassignable (MBNR) - const - invariant (immutable) For primitive types and static arrays thereof, only two of these are distinct: reassignable and invariant. If something of such a type is declared const, it actually becomes invariant. The constancy of a struct is determined by two factors: the constancy of its members and any constancy attributes with which the struct as a whole is declared. The constancy of a struct as determined by its members works like this: - if all members are reassignable, it is reassignable - if all members are invariant, it is invariant - if all members are const, or all members are const or invariant, it is const - otherwise, it is MBNR The otherwise is if the struct has a mixture of reassignable and const and/or invariant members, or has any MBNR members. Or equivalently, if struct members of structs are flattened out, the overall struct is MBNR iff there is a mixture of reassignable and const and/or invariant members. The essence of MBNR is that the struct cannot be reassigned, but the constancy levels of the struct's members shine through. Of course, it would still be possible to declare a struct 'variable' as const or invariant, and this would be a matter of tightening the constancy from that which is in the type. --
[Issue 2625] Creating new struct with literal bypasses immutability of members if struct is in array
http://d.puremagic.com/issues/show_bug.cgi?id=2625 ma...@pochta.ru changed: What|Removed |Added OtherBugsDependingO||2573 nThis|| --- Comment #2 from ma...@pochta.ru 2009-04-02 07:02 --- According to specs http://digitalmars.com/d/2.0/struct.html works() is correct. I think, broken() is correct, since invariant data can be referenced directly, so it's incorrect for it to change in time. --
[Issue 2625] Creating new struct with literal bypasses immutability of members if struct is in array
http://d.puremagic.com/issues/show_bug.cgi?id=2625
dsim...@yahoo.com changed:
What|Removed |Added
Severity|normal |critical
Keywords|spec|accepts-invalid
Summary|Inconsistent behavior with |Creating new struct with
|const/immutable struct |literal bypasses
|members |immutability of members if
||struct is in array
--- Comment #1 from dsim...@yahoo.com 2009-04-01 15:06 ---
Upon thinking about this some more, it's pretty clear that one should *not* be
able to change the value in an existing memory location by creating a whole new
struct, i.e. the following is bad:
struct Pair {
immutable uint g1;
uint g2;
}
void main() {
Pair[1] stuff;
stuff[0] = Pair(1, 2); // Modify immutable by rebinding whole struct.
}
Note that the same thing happens if stuff is a dynamic array instead of a
static array. Upping severity, giving more descriptive title.
--
