[Issue 8011] BigInt ++ and -- do wrong thing on negative numbers
http://d.puremagic.com/issues/show_bug.cgi?id=8011 Don clugd...@yahoo.com.au changed: What|Removed |Added Status|NEW |RESOLVED CC||clugd...@yahoo.com.au Resolution||FIXED -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 8011] BigInt ++ and -- do wrong thing on negative numbers
http://d.puremagic.com/issues/show_bug.cgi?id=8011
Ary Borenszweig a...@esperanto.org.ar changed:
What|Removed |Added
CC||a...@esperanto.org.ar
--- Comment #3 from Ary Borenszweig a...@esperanto.org.ar 2012-05-01 23:57:53
PDT ---
(In reply to comment #1)
The root cause is in bigint.d, in the opUnary() function. BigInt uses an
underlying BigUint and maps the ++ and -- operators directly through to the
BigUint as addition and subtraction, respectively, disregarding the BigInt's
sign. However, this is wrong. Signed ++ and -- must be passed through as
subtraction and addition, respectively.
I modified the function by commenting out the two errant lines and replacing
them each with a correct one. This is a proof-of-concept fix for the bug.
// non-const unary operations
BigInt opUnary(string op)() if (op==++ || op==--)
{
static if (op==++)
{
//data = BigUint.addOrSubInt(data, 1UL, false, sign);
data = BigUint.addOrSubInt(data, 1UL, sign ? true : false, sign);
return this;
}
else static if (op==--)
{
//data = BigUint.addOrSubInt(data, 1UL, true, sign);
data = BigUint.addOrSubInt(data, 1UL, sign ? false : true, sign);
return this;
}
}
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[Issue 8011] BigInt ++ and -- do wrong thing on negative numbers
http://d.puremagic.com/issues/show_bug.cgi?id=8011
--- Comment #4 from Ary Borenszweig a...@esperanto.org.ar 2012-05-01 23:58:55
PDT ---
sign is already a boolean, so it's simpler to do:
// non-const unary operations
BigInt opUnary(string op)() if (op==++ || op==--)
{
static if (op==++)
{
data = BigUint.addOrSubInt(data, 1UL, sign, sign);
return this;
}
else static if (op==--)
{
data = BigUint.addOrSubInt(data, 1UL, !sign, sign);
return this;
}
}
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[Issue 8011] BigInt ++ and -- do wrong thing on negative numbers
http://d.puremagic.com/issues/show_bug.cgi?id=8011 --- Comment #5 from github-bugzi...@puremagic.com 2012-05-02 16:46:08 PDT --- Commits pushed to master at https://github.com/D-Programming-Language/phobos https://github.com/D-Programming-Language/phobos/commit/bd72ae7d36e2fafe3a4c00dc9e4c568366cacb03 Fix issue 8011 BigInt ++ and -- do wrong thing on negative numbers Patch by Ary Borenszweig https://github.com/D-Programming-Language/phobos/commit/87dfaa82dbb8ff129b46037830ca7f9845ab6664 Merge pull request #564 from donc/bigint8011 Fix issue 8011 BigInt ++ and -- do wrong thing on negative numbers -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
