<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_extra"><br><div class="gmail_quote">On 25 September 2016 at 22:21, Chris Jones <span dir="ltr"><<a href="mailto:jonesc@hep.phy.cam.ac.uk" target="_blank">jonesc@hep.phy.cam.ac.uk</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br><div dir="auto"><span class=""><div><br></div><div><br>On 25 Sep 2016, at 2:49 pm, Yongwei Wu <<a href="mailto:wuyongwei@gmail.com" target="_blank">wuyongwei@gmail.com</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="ltr"><div><br></div><div class="gmail_extra"><br><div class="gmail_quote">On 25 September 2016 at 21:35, Chris Jones <span dir="ltr"><<a href="mailto:jonesc@hep.phy.cam.ac.uk" target="_blank">jonesc@hep.phy.cam.ac.uk</a>></span> wrote:<br><blockquote style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex" class="gmail_quote"><div dir="auto"><span><div><br></div><div><br>On 25 Sep 2016, at 2:25 pm, Brandon Allbery <<a href="mailto:allbery.b@gmail.com" target="_blank">allbery.b@gmail.com</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="ltr"><div class="gmail_extra"><br><div class="gmail_quote">On Sun, Sep 25, 2016 at 8:29 AM, Ken Cunningham <span dir="ltr"><<a href="mailto:ken.cunningham.webuse@gmail.com" target="_blank">ken.cunningham.webuse@gmail.c<wbr>om</a>></span> wrote:<br><blockquote style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex" class="gmail_quote">What is happening exactly on my MacPros running 10.11, I wonder? Software installed by macports on 10.11 is using clang++ (mostly) and g++ (sometimes). clang++ is linking against libc++, and g++ is presumably linking against libstdc++ as that is what it does -- yet there appear to be no visible issues...and these libraries find each other. </blockquote></div><br>An additional complication is that it's not using the same libstdc++: it's using the GPL3 one with C++11 support, not Apple's GPL2/pre-C++11 one. So potentially the clash here is between the two libstdc++ versions, not libstdc++ and libc++.<br></div></div></div></blockquote><div><br></div></span>Indeed, mixing two different libstdc++ runtimes has the same sort of issues as mixing libstd++ with libc++.<br></div></blockquote></div><br clear="all">I actually do not think this is normally an issue. If the dynamic
libraries manage the lifetime of their own object, i.e. do not do
something like creating an object in a library but not providing a
function to destroy it (so that the application needs to delete it), bad
things should not occur. At least that is the only case I am aware of.
(I encountered this kind of problems on Windows, which was even worse,
as each new release of MSVC brought in a different C/C++ runtime, which
can also be either static or dynamic.)<br></div></div></div></blockquote><div><br></div></span><div><span style="background-color:rgba(255,255,255,0)">Its exactly the same situation as with libc++ v libstdc++. There are ways it can be ok and ways you can run into problems. The only guaranteed way (I know of) to not have issues is not to do it.</span><br></div></div></blockquote></div><br><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">My point is that a well-designed application/library should not do this. And if it did it, problems might have occurred long ago (esp. on Windows, supposing a Windows port exists). If things are going on well so far, we probably do not need to worry much. At least I do not see what we can do to help the case at the moment.<br clear="all"></div><br>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div>Yongwei Wu<br>URL: <a href="http://wyw.dcweb.cn/" target="_blank">http://wyw.dcweb.cn/</a></div></div></div>
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