[Issue 9433] Deprecate delete

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=9433


FG <home at fgda.pl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |home at fgda.pl


--- Comment #1 from FG <home at fgda.pl> 2013-01-31 07:14:06 PST ---
(In reply to comment #0)
> But I expect a message like:
> temp.d(5): Deprecation: use of delete is deprecated; use destroy (and
> core_memory.GC.free) instead.

Delete cannot be deprecated because there is no properly working replacement
for delete at this moment. Look at the following code:

    import std.stdio, core.memory;
    class C { 
        byte[] s;
        this() { s = new byte[40 * 1024 * 1024]; }
    }
    void main(string[] args) {
        for (int i=0, j=0; i < 1000; i++) {
            auto x = new C();
            // delete x.s;               // A
            // x.s.destroy();            // B
            // GC.free(cast(void*)x.s);  // C
        }
    }


Let's see memory usage on windows when line A, B or C get uncommented, with
code compiled using DMD32 v2.060 and GDC (tmd64-1) 4.6.1:

code | dmd32 | gdc64
-    | OOM   | 160MB
A    | 40MB  |  40MB
B    | OOM   | 160MB
B+C  | OOM   | 160MB
C    | 40MB  |  40MB

where OOM = OutOfMemoryError and 160MB is sometimes 120MB.

Only lines A and C are acceptable memory-wise but C doesn't run destructors.
Combining C with B calls destructors but doesn't free memory. Even the manual
for core.memory.free tells to use delete in such cases! So how can you get rid
of delete?

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------