remove obsolete Boost dependency

Boost makes building a piece of software much more difficult than
necessary.  It's a huge library, and just uncompressing it takes a
considerable amount of time. MPD only used a tiny fraction of it, yet
its header bloat made the MPD build very slow.  Locating Boost was
difficult due to its arcane build system and its resistance to use
pkg-config; it's always a special case.  MPD could never use features
of newer Boost versions because Linux distributions always shipped old
Boost versions.  Boost made everything complicated and slow.

So, finally, after getting rid of GLib (commit ccdb94b06c), switching
to C++ and using Boost (commit 0801b3f495), we've finally get rid of
it 8 years later.

Unfortunately, I had to reimplement parts of it along the way
(e.g. IntrusiveList).  Kind of NIH, but on the other hand, compiling
MPD has become much easier for users.

.github/workflows/build.yml

@@ -60,7 +60,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             ${{ matrix.cxx }} ${{matrix.cc }} \
-            libfmt-dev libboost-dev \
+            libfmt-dev \
             libgtest-dev \
             libpcre2-dev \
             libsystemd-dev libdbus-1-dev \
@@ -137,7 +137,6 @@ jobs:
           brew install \
             meson ninja \
             fmt \
-            boost \
             googletest \
             icu4c \
             ffmpeg \

NEWS

@@ -25,6 +25,7 @@ ver 0.24 (not yet released)
   - GCC 10 or clang 11 (or newer) recommended
 * static partition configuration
 * remove Haiku support
+* remove Boost dependency
 * require libfmt 7 or later
 
 ver 0.23.12 (2023/01/17)

android/build.py

@@ -160,7 +160,6 @@ thirdparty_libs = [
     openssl,
     curl,
     libnfs,
-    boost,
 ]
 
 # build the third-party libraries

doc/user.rst

@@ -60,7 +60,6 @@ In any case, you need:
 * a C++20 compiler (e.g. GCC 10 or clang 11)
 * `Meson 0.56.0 <http://mesonbuild.com/>`__ and `Ninja
   <https://ninja-build.org/>`__
-* Boost 1.58
 * pkg-config 
 
 Each plugin usually needs a codec library, which you also need to
@@ -95,7 +94,6 @@ For example, the following installs a fairly complete list of build dependencies
       libsqlite3-dev \
       libsystemd-dev \
       libgtest-dev \
-      libboost-dev \
       libicu-dev \
       libchromaprint-dev \
       libgcrypt20-dev

meson.build

@@ -240,13 +240,6 @@ inc = include_directories(
   '.',
 )
 
-boost_dep = dependency('boost', version: '>= 1.58')
-if boost_dep.version() == '1.67'
-  # https://github.com/MusicPlayerDaemon/MPD/pull/384
-  # https://github.com/boostorg/lockfree/commit/12726cda009a855073b9bedbdce57b6ce7763da2
-  warning('Your Boost version 1.67 is known to be buggy, and the MPD build will fail. Please upgrade to Boost 1.68 or later.')
-endif
-
 subdir('src/lib/fmt')
 
 log = static_library(

python/build/boost.py

@@ -1,28 +0,0 @@
-import os, shutil
-import re
-
-from build.project import Project
-
-class BoostProject(Project):
-    def __init__(self, url, md5, installed,
-                 **kwargs):
-        m = re.match(r'.*/boost_(\d+)_(\d+)_(\d+)\.tar\.bz2$', url)
-        version = "%s.%s.%s" % (m.group(1), m.group(2), m.group(3))
-        Project.__init__(self, url, md5, installed,
-                         name='boost', version=version,
-                         **kwargs)
-
-    def _build(self, toolchain):
-        src = self.unpack(toolchain)
-
-        # install the headers manually; don't build any library
-        # (because right now, we only use header-only libraries)
-        includedir = os.path.join(toolchain.install_prefix, 'include')
-        dest = os.path.join(includedir, 'boost')
-        shutil.rmtree(dest, ignore_errors=True)
-        shutil.copytree(os.path.join(src, 'boost'), dest)
-
-        # touch the boost/version.hpp file to ensure it's newer than
-        # the downloaded Boost tarball, to avoid reinstalling Boost on
-        # every run
-        os.utime(os.path.join(toolchain.install_prefix, self.installed))

python/build/libs.py

@@ -8,7 +8,6 @@ from build.cmake import CmakeProject
 from build.autotools import AutotoolsProject
 from build.ffmpeg import FfmpegProject
 from build.openssl import OpenSSLProject
-from build.boost import BoostProject
 from build.jack import JackProject
 
 libmpdclient = MesonProject(
@@ -448,9 +447,3 @@ jack = JackProject(
     '38f674bbc57852a8eb3d9faa1f96a0912d26f7d5df14c11005ad499c8ae352f2',
     'lib/pkgconfig/jack.pc',
 )
-
-boost = BoostProject(
-    'https://boostorg.jfrog.io/artifactory/main/release/1.81.0/source/boost_1_81_0.tar.bz2',
-    '71feeed900fbccca04a3b4f2f84a7c217186f28a940ed8b7ed4725986baf99fa',
-    'include/boost/version.hpp',
-)

python/build/meson.py

@@ -96,9 +96,6 @@ def configure(toolchain, src, build, args=()):
 
     env = toolchain.env.copy()
 
-    # Meson 0.54 requires the BOOST_ROOT environment variable
-    env['BOOST_ROOT'] = toolchain.install_prefix
-
     subprocess.check_call(configure, env=env)
 
 class MesonProject(Project):

src/apple/meson.build

@@ -5,9 +5,6 @@ endif
 
 audiounit_dep = declare_dependency(
   link_args: ['-framework', 'AudioUnit', '-framework', 'CoreAudio', '-framework', 'CoreServices'],
-  dependencies: [
-    boost_dep,
-  ],
 )
 
 apple = static_library(

src/db/meson.build

@@ -53,7 +53,6 @@ db_glue = static_library(
   db_glue_sources,
   include_directories: inc,
   dependencies: [
-    boost_dep,
     fmt_dep,
     log_dep,
   ],

src/input/meson.build

@@ -10,9 +10,6 @@ input_api = static_library(
   'ProxyInputStream.cxx',
   'LastInputStream.cxx',
   include_directories: inc,
-  dependencies: [
-    boost_dep,
-  ],
 )
 
 input_api_dep = declare_dependency(
@@ -44,7 +41,6 @@ input_glue = static_library(
   'cache/Stream.cxx',
   include_directories: inc,
   dependencies: [
-    boost_dep,
     log_dep,
   ],
 )

src/output/plugins/meson.build

@@ -36,7 +36,7 @@ if get_option('httpd')
     'httpd/HttpdClient.cxx',
     'httpd/HttpdOutputPlugin.cxx',
   ]
-  output_plugins_deps += [ event_dep, net_dep, boost_dep ]
+  output_plugins_deps += [ event_dep, net_dep ]
   need_encoder = true
 endif
 
@@ -177,7 +177,6 @@ output_plugins = static_library(
     sles_dep,
     winmm_dep,
     wasapi_dep,
-    boost_dep,
     output_plugins_deps,
   ],
 )

src/storage/meson.build

@@ -19,7 +19,6 @@ storage_glue = static_library(
   'Configured.cxx',
   include_directories: inc,
   dependencies: [
-    boost_dep,
     log_dep,
   ],
 )

win32/build.py

@@ -106,7 +106,6 @@ thirdparty_libs = [
     curl,
     libnfs,
     jack,
-    boost,
 ]
 
 # build the third-party libraries