Boost C++ Libraries: Ticket #786: bug in iostreams/copy.hpp line 81

alexis_wilke — Mon, 11 Dec 2006 05:48:52 GMT

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Mathieu,
Actually, the copy operator will test if(_first < _last) <do the copy> and if amt is -1 that condition will be false. Yet I agree that your way we would avoid one call and one variable ('done' in the original loop). I'm not part of boost so I cannot decide whether to apply the change. But this is only an optimization.
Alexis

anonymous — Tue, 15 May 2007 16:33:51 GMT

There is a patch for this in "official patch format" in: http://article.gmane.org/gmane.comp.lib.boost.user/23522

chris@… — Sat, 30 Jun 2007 00:02:11 GMT

Alexis,

My copy operator did not perform your test and I saw the bug (5 or 6 levels down the stack a copy for last-first would eventually SIGSEGV in memcpy.)

Chris DUrso

qbowater@… — Sat, 07 Jul 2007 03:47:15 GMT

Replying to alexis_wilke:

Mathieu,

Actually, the copy operator will test if(_first < _last) <do the copy> and if amt is -1 that condition will be false. Yet I agree that your way we would avoid one call and one variable ('done' in the original loop). I'm not part of boost so I cannot decide whether to apply the change. But this is only an optimization. Alexis

In VC8 DEBUG mode,it will assert in std::copy because "first > last". It make difficult to debug program.I think it should be repaired necessarily.

anonymous — Wed, 11 Jul 2007 04:10:35 GMT

This looks like a duplicate of #1070

component changed; severity set

Daryle Walker — Fri, 03 Aug 2007 12:17:21 GMT

component None → iostreams
severity → Problem

status, resolution changed

Jonathan Turkanis — Tue, 25 Dec 2007 08:51:01 GMT

status assigned → closed
resolution None → fixed

Fixed in [42294] in branches/iostreams_dev, to be merged into trunk shortly. The fix is a slight modification of the suggestion above.