• =?UTF-8?B?Tm9yZGzDtnc=?= (62/62) Oct 21 2016 The following code
• =?UTF-8?B?Tm9yZGzDtnc=?= (10/11) Oct 21 2016 If this is changed to
• Jonathan M Davis via Digitalmars-d (8/11) Oct 21 2016 Well, I wouldn't expect it to work to use a non-copyable type as a key, ...
• =?UTF-8?B?Tm9yZGzDtnc=?= (7/21) Nov 04 2016 AFACT, it *should* be able to work with non-copyable types if

=?UTF-8?B?Tm9yZGzDtnc=?= <per.nordlow gmail.com> writes:

The following code


import std.stdio;

struct S(E)
{
     static typeof(this) withElement(E x)
     {
         typeof(return) that;
         that._ptr = cast(E*)malloc(1*E.sizeof);
         *(that._ptr) = x;
         return that;
     }

     //  disable this(this);
     this(this) { assert(false); }

     ~this()
     {
         writeln("freeing:", _ptr);
         free(_ptr);
     }

     E* _ptr;
}

unittest
{
     alias Key = S!int;
     int[Key] x;
     writeln("before");
     x[Key.withElement(11)] = 42;
     writeln("after");
}

extern (C):
void* malloc(size_t);
void free(void*);


assert as


before
freeing:706490
core.exception.AssertError aaNoMoveCrash.d(18): Assertion failure
----------------
??:? [0x411a3f]
??:? [0x41028f]
aaNoMoveCrash.d:18 [0x402b73]
??:? [0x413be5]
??:? [0x4126a8]
aaNoMoveCrash.d:34 [0x402a46]
??:? [0x410230]
??:? [0x41c8a0]
??:? [0x4113cb]
??:? [0x4162e6]
??:? [0x416374]
??:? [0x416277]
??:? [0x4113a7]
??:? [0x41c792]
??:? [0x412dfa]
??:? [0x412d98]
??:? [0x412d12]
??:? [0x4103bf]
??:? __libc_start_main [0x8452a82f]
freeing:706490


It seems AA's doesn't respect disabling of postblit for its 
Key-type even when it's sent as an r-value.

This is a serious bug.

Is this know?

Can somebody give hints to where I can start digging in DMD for 
fixing this?

=?UTF-8?B?Tm9yZGzDtnc=?= <per.nordlow gmail.com> writes:

On Friday, 21 October 2016 at 12:18:28 UTC, Nordlöw wrote:
     this(this) { assert(false); }

If this is changed to


        disable this(this);


I instead get a segfault because of a double free:


before
freeing:591490
after
freeing:591490
*** Error in ...

Pretty serious bug.

Jonathan M Davis via Digitalmars-d <digitalmars-d puremagic.com> writes:

On Friday, October 21, 2016 12:18:28 Nordlöw via Digitalmars-d wrote:
 It seems AA's doesn't respect disabling of postblit for its
 Key-type even when it's sent as an r-value.

 This is a serious bug.

Well, I wouldn't expect it to work to use a non-copyable type as a key, but
that should just result in a compilation error, not the mess that you're
seeing. It wouldn't surprise me at all if the problem relates to the fact
that the AA implementation uses void* internally (at least, from what I
recall, that's what it does, which historically has meant a number of fun
type-related bugs).

- Jonathan M Davis

=?UTF-8?B?Tm9yZGzDtnc=?= <per.nordlow gmail.com> writes:

On Friday, 21 October 2016 at 18:35:38 UTC, Jonathan M Davis 
wrote:
 On Friday, October 21, 2016 12:18:28 Nordlöw via Digitalmars-d 
 wrote:
 It seems AA's doesn't respect disabling of postblit for its 
 Key-type even when it's sent as an r-value.

 This is a serious bug.

 Well, I wouldn't expect it to work to use a non-copyable type 
 as a key, but that should just result in a compilation error, 
 not the mess that you're seeing. It wouldn't surprise me at all 
 if the problem relates to the fact that the AA implementation 
 uses void* internally (at least, from what I recall, that's 
 what it does, which historically has meant a number of fun 
 type-related bugs).

 - Jonathan M Davis

AFACT, it *should* be able to work with non-copyable types if 
argument is an r-value. If somebody points out where to start 
digging for this DMD I can give it at try.

1. issue a error when index is an l-value of noncopyable type
2. move the index if it's an r-value