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Re: Migration to C++ (?)



I wrote boost is huge not bloatware.
Yes, usage of boost has many-many more benefit which is larger than
the size of boost in cases. But using only some functions from
boost... I think sometimes easier create these functions than import
many libs.

But if any program needs boost you should install it. Many systems
doesn't have boost installed - why install it because of only one
simple and _lightweight_ program? I hope it's clear what I want to
say.

I think Thorsten has right: what is the benefit of boost in hlwm?

Zsolt


2014-07-22 9:12 GMT+02:00 Christian Dietrich <stettberger _at_ dokucode _dot_ de>:
> Zsolt Udvari <udvzsolt _at_ gmail _dot_ com> writes:
>
> > 2014-07-22 4:36 GMT+02:00 Christopher Meng <cickumqt _at_ gmail _dot_ com>:
> > > Any plan of C++ on Boost?
>
> > Is it serious? Herbstluftwm is a small, lightweight window manager, I
> > think, depends on huge boost is a very-very bad idea...
>
> Ok, so let's check the facts here. Boost is a C++ Template
> Library. Boost itself is a large project that is right, but is it a
> inseperable blob? Or to give the question in other words: Do we always
> pay the full price of using boost, when only using a small subset of all
> features. Because that would be bloat.
>
> Ok, first of all, there are nearly no shared libraries in boost:
>
> -rw-r--r-- 1 root root 128K Jun  4  2013 /usr/lib/libboost_filesystem.so.1.49.0
> -rw-r--r-- 1 root root 1.1M Jun  4  2013 /usr/lib/libboost_regex.so.1.49.0
> -rw-r--r-- 1 root root  15K Jun  4  2013 /usr/lib/libboost_system.so.1.49.0
> -rw-r--r-- 1 root root 107K Jun  4  2013 /usr/lib/libboost_thread.so.1.49.0
>
> And you "infect" your software only with with those libraries, when you
> use the corresponding boost feature. So, here a module separation is in
> place. But is this bad? herbstluftwm already links again various
> libraries.
>
> $ ldd =herbstluftwm | cut -d " " -f 3 | xargs ls -lhL
> -rwxr-xr-x 1 root root 1.8M Apr 12 12:38 /lib/x86_64-linux-gnu/libc.so.6
> -rw-r--r-- 1 root root  15K Apr 12 12:38 /lib/x86_64-linux-gnu/libdl.so.2
> -rw-r--r-- 1 root root 1.1M Apr  3 16:05 /lib/x86_64-linux-gnu/libglib-2.0.so.0
> -rw-r--r-- 1 root root 247K Dec  3  2013 /lib/x86_64-linux-gnu/libpcre.so.3
> -rwxr-xr-x 1 root root 139K Apr 12 12:38 /lib/x86_64-linux-gnu/libpthread.so.0
> -rw-r--r-- 1 root root 1.3M Dec  4  2013 /usr/lib/x86_64-linux-gnu/libX11.so.6
> -rw-r--r-- 1 root root  15K Jun 15  2013 /usr/lib/x86_64-linux-gnu/libXau.so.6
> -rw-r--r-- 1 root root  23K Apr 30  2012 /usr/lib/x86_64-linux-gnu/libXdmcp.so.6
> -rw-r--r-- 1 root root  72K Jun 30  2013 /usr/lib/x86_64-linux-gnu/libXext.so.6
> -rw-r--r-- 1 root root  11K Jul  1  2013 /usr/lib/x86_64-linux-gnu/libXinerama.so.1
> -rw-r--r-- 1 root root 123K Jan 15  2014 /usr/lib/x86_64-linux-gnu/libxcb.so.1
>
> So, how much bloat are the template instantiations? Let's do a little
> experiment, just to get an impression and not to give full evidence. How
> is it with the boost::bind library?
>
> ////////////////////////////////////////////////////////////////
> L qy03fugy@faui49r /tmp % cat test.cc
> #include <iostream>
> #ifdef USE_BOOST
> #include "boost/bind.hpp"
> #endif
>
> void nine_arguments(
>                     int i1,int i2,int i3,int i4,
>                     int i5,int i6,int i7,int i8, int i9) {
>     std::cout << i1 << i2 << i3 << i4 << i5
>               << i6 << i7 << i8 << i9 << '\n';
> }
>
> void(*funcptr)(int, int, int, int, int,
>                int, int, int, int) = nine_arguments;
>
> int main(int argc, int *argv[]) {
>     int i1=1,i2=2,i3=3,i4=4,i5=5,i6=6,i7=7,i8=8,i9=9;
>
> #ifdef USE_BOOST
>     (boost::bind(funcptr,_9,_2,_1,_6,_3,_8,_4,_5,_7))
>         (i1,i2,i3,i4,i5,i6,i7,i8,i9);
> #else
>     funcptr(i9, i2, i1, i6, i3, i8, i4, i5, i7);
> #endif
>     return 0;
> }
> L qy03fugy@faui49r /tmp % g++ test.cc -D USE_BOOST -o with-boost; g++ test.cc -D USE_BOOST -o with-boost
> test.cc:16:5: warning: second argument of ‘int main(int, int**)’ should be ‘char **’ [-Wmain]
> [...]
> L qy03fugy@faui49r /tmp % ./with-boost; ./without-boost
> 921638457
> 921638457
> L qy03fugy@faui49r /tmp % ls -lh with*
> -rwxr-xr-x 1 qy03fugy immdstud  22K Jul 22 09:05 with-boost*
> -rwxr-xr-x 1 qy03fugy immdstud 8.9K Jul 22 08:53 without-boost*
>
>
> ////////////////////////////////////////////////////////////////
>
> So here we see a little bloat, but we used g++ without
> optimizations. But what happens if we enable the least optimization
> level -O1?
>
> L qy03fugy@faui49r /tmp % g++ test.cc -D USE_BOOST -o with-boost -O1; g++ test.cc -D USE_BOOST -o with-boost -O1
> test.cc:16:5: warning: second argument of ‘int main(int, int**)’ should be ‘char **’ [-Wmain]
> [...]
> L qy03fugy@faui49r /tmp % ./with-boost; ./without-boost
> 921638457
> 921638457
> L qy03fugy@faui49r /tmp % ls -lh with*
> -rwxr-xr-x 1 qy03fugy immdstud 8.9K Jul 22 09:05 with-boost*
> -rwxr-xr-x 1 qy03fugy immdstud 8.9K Jul 22 08:53 without-boost*
>
> ////////////////////////////////////////////////////////////////
>
> And suddenly all my macro "bloat" disappears. Because macros are often
> used to hide boiler plate code in a nice API. When you want to know more
> about C++ template programming I would recommend reading
>
>    Modern C++ Design; Andrei Alexandescu
>
> So, after I've shown that boost does not necessarily mean bloat, I want
> to empasize that I do *not* recommend the usage of boost in all cases or
> that it should be used extensively in herbstluftwm. BUT, if you make the
> claim, that boost is out of hell all is big, large and whatever, please
> check the facts first. Using Boost it not equal to Using Boost. That
> boot inhibits always bloat is a myth.
>
> chris