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digitalmars.D.bugs - [Issue 3897] New: Sporadic incorrectness with builtin AAs

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=3897

           Summary: Sporadic incorrectness with builtin AAs
           Product: D
           Version: 2.041
          Platform: Other
        OS/Version: Windows
            Status: NEW
          Severity: regression
          Priority: P2
         Component: DMD
        AssignedTo: nobody puremagic.com
        ReportedBy: dsimcha yahoo.com


--- Comment #0 from David Simcha <dsimcha yahoo.com> 2010-03-08 06:38:43 PST ---
Here's about the best I can do to reproduce this issue.  It showed up in a
monte carlo unittest of one of my associative array implementations that tested
whether it gets the same answers as the builtin implementation.  Probably some
subtle memory corruption issue.

import std.stdio, std.random, std.conv;

void main() {
    // Monte carlo unit test builtin hash table.
    uint[uint] table;
    auto gen = Random(42);
    foreach(i; 0..1_000_000) {
        auto num1 = gen.front();
        gen.popFront();
        auto num2 = gen.front();
        gen.popFront();

        table[num1] = num2;
    }

    // Note that we're using the same seed again.
    gen = Random(42);
    foreach(i; 0..1_000_000) {
        auto num1 = gen.front();
        gen.popFront();
        auto num2 = gen.front();
        gen.popFront();

        assert(num1 in table);
        assert(table[num1] == num2);
    }
}

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parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=3897


David Simcha <dsimcha yahoo.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID


--- Comment #1 from David Simcha <dsimcha yahoo.com> 2010-03-08 06:54:19 PST ---
Never mind.  I filed this report in a hurry.  While I still think something
screwy is going on with the builtin AAs, this is not a valid way to reproduce
it.  Will file a new report when I have more time to look into the problem.

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