Building with boost 1.54: "Boost.Signals is no longer being maintained and is now deprecated. Please switch to Boost.Signals2."

[Hans Joachim Desserud]

Boost version 1.54 was recently packaged in Arch Linux and building WL now prints several warnings like this:

In file included from /home/user/widelands/src/wui/minimap.h:23:0,
                 from /home/user/widelands/src/graphic/render/minimaprenderer.cc:26:
/usr/include/boost/signal.hpp:17:4: warning: #warning "Boost.Signals is no longer being maintained and is now deprecated. Please switch to Boost.Signals2. To disable this warning message, define BOOST_SIGNALS_NO_DEPRECATION_WARNING." [-Wcpp]
 # warning "Boost.Signals is no longer being maintained and is now deprecated. Please switch to Boost.Signals2. To disable this warning message, define BOOST_SIGNALS_NO_DEPRECATION_WARNING."
    ^

I assume this affects all places where Signals are used. Not being familiar with boost, I don't know how severe this is, whether we can except the old Signals to disappear in a future release or if we can stick with it for the foreseeable future. I don't know how easy it would be to support both Signals and Signals2 either, in order to support building with older boost versions.

This was mainly posted as a heads-up and will probably not cause any real problems for a while, but might be something to consider.

[Jens Beyer (qcumber-some)]

Comparison:

http://www.boost.org/doc/libs/1_54_0/doc/html/signals2/api_changes.html#signals2.porting

[Hans Joachim Desserud (hjd)]

Thanks for the link Jens. From the warning I assumed it was something introduced recently, but it looks like signals2 has been available in parallell with signals since boost 1.39 with only minor changes.

For whoever ends up porting this, keep in mind that we wish to support Ubuntu 12.04 which ships boost 1.46 by default (though the last change listed under API development is in 1.45, so hopefully we should be fine.

We should probably port over to the new API sometime during the build19 cycle, though if someone wants to tackle it sooner, feel free. :)

[Jens Beyer (qcumber-some)]

Ubuntu 12.04 LTS (precise) also ships boost 1.48 (next to 1.46.1 which is default).

[SirVer (sirver)]

Released in build-18 rc1.