Re: [Boost-bugs] [Boost C++ Libraries] #3844: boost.thread doesn't work with gcc-4.5 in c++0x mode

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #3844: boost.thread doesn't work with gcc-4.5 in c++0x mode
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-04-28 18:19:03

#3844: boost.thread doesn't work with gcc-4.5 in c++0x mode
----------------------------------------------------+-----------------------
 Reporter:  Sebastian Mingramm <s.mingramm@…>       |       Owner:  anthonyw
     Type:  Bugs                                    |      Status:  new     
Milestone:  Boost 1.42.0                            |   Component:  thread  
  Version:  Boost 1.41.0                            |    Severity:  Problem 
 Keywords:                                          |  
----------------------------------------------------+-----------------------

Comment(by mlrus@…):

 Might be a boost bug "In fact it's try to bind the reference to an lvalue,
 which is invalid" according to Bugzilla Bug 43915
 {{{
    inline thread&& move(thread&& t)
    {
        return t;
    }

 At the point of return 't' is an lvalue so to return it as an rvalue it
 needs
 to be static_cast<thread&&>(t)
 }}}

 Replying to [ticket:3844 Sebastian Mingramm <s.mingramm@…>]:
 > {{{
 > $ cat test.cpp
 > #include <boost/thread.hpp>
 > int main() {}
 >
 > $ g++ -v
 > }}}
 > Using built-in specs.
 > COLLECT_GCC=g++
 > COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-pc-linux-gnu/4.5.0
 /lto-wrapper
 > Target: x86_64-pc-linux-gnu
 > Configured with: ./configure --host=x86_64-pc-linux-gnu --build=x86_64
 -pc-linux-gnu --disable-altivec --disable-fixed-point --with-ppl --with-
 cloog --disable-nls --with-system-zlib --disable-checking --disable-werror
 --enable-secureplt --enable-multilib --enable-libmudflap --disable-libssp
 --enable-libgomp --enable-cld --enable-languages=c,c++ --enable-shared
 --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu
 --enable-lto
 > Thread model: posix
 > gcc version 4.5.0 20100115 (experimental) (GCC)
 >
 > {{{
 > $ g++ test.cpp -std=c++0x
 > }}}
 > In file included from /usr/include/boost/thread/thread.hpp:22:0,
 >                  from /usr/include/boost/thread.hpp:13,
 >                  from test.cpp:1:
 > /usr/include/boost/thread/detail/thread.hpp: In function
 'boost::thread&& boost::move(boost::thread&&)':
 > /usr/include/boost/thread/detail/thread.hpp:349:16: error: invalid
 initialization of reference of type 'boost::thread&&' from expression of
 type 'boost::thread'
 > In file included from
 /usr/include/boost/thread/detail/thread_heap_alloc.hpp:17:0,
 >                  from /usr/include/boost/thread/detail/thread.hpp:13,
 >                  from /usr/include/boost/thread/thread.hpp:22,
 >                  from /usr/include/boost/thread.hpp:13,
 >                  from test.cpp:1:
 > /usr/include/boost/thread/pthread/thread_heap_alloc.hpp: In function 'T*
 boost::detail::heap_new(A1&&) [with T = boost::detail::thread_data<void
 (*)()>, A1 = void (*&)()]':
 > /usr/include/boost/thread/detail/thread.hpp:130:95:   instantiated from
 here
 > /usr/include/boost/thread/pthread/thread_heap_alloc.hpp:24:47: error:
 cannot bind 'void (*)()' lvalue to 'void (*&&)()'
 > /usr/include/boost/thread/detail/thread.hpp:43:13: error:   initializing
 argument 1 of 'boost::detail::thread_data<F>::thread_data(F&&) [with F =
 void (*)()]'
 > In file included from /usr/include/boost/thread/pthread/mutex.hpp:11:0,
 >                  from /usr/include/boost/thread/mutex.hpp:16,
 >                  from
 /usr/include/boost/thread/pthread/thread_data.hpp:12,
 >                  from /usr/include/boost/thread/thread.hpp:17,
 >                  from /usr/include/boost/thread.hpp:13,
 >                  from test.cpp:1:
 > /usr/include/boost/thread/locks.hpp: In member function
 'boost::unique_lock<Mutex>&
 boost::unique_lock<Mutex>::operator=(boost::unique_lock<Mutex>&&) [with
 Mutex = boost::mutex, boost::unique_lock<Mutex> =
 boost::unique_lock<boost::mutex>]':
 > /usr/include/boost/thread/future.hpp:414:91:   instantiated from here
 > /usr/include/boost/thread/locks.hpp:269:13: error: cannot bind
 'boost::unique_lock<boost::mutex>' lvalue to
 'boost::unique_lock<boost::mutex>&&'
 > /usr/include/boost/thread/locks.hpp:279:14: error:   initializing
 argument 1 of 'void
 boost::unique_lock<Mutex>::swap(boost::unique_lock<Mutex>&&) [with Mutex =
 boost::mutex, boost::unique_lock<Mutex> =
 boost::unique_lock<boost::mutex>]'

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3844#comment:3>
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