bash-3.2# cat  build.2.log

Building the Boost C++ Libraries.

After the build, the headers will be located at
  
    /usr/local/boost_1_42_0
    
The libraries will be located at  
    
    /usr/local/boost_1_42_0/stage/lib
     
Use 'bjam install --prefix=<path>' if you wish to install headers and 
libraries to a different location and remove the source tree.


warning: Building Boost.Regex with the optional Unicode/ICU support disabled.
note: Please refer to the Boost.Regex documentation for more information
note: this is a strictly optional feature.
warning: Graph library does not contain MPI-based parallel components.
note: to enable them, add "using mpi ;" to your user-config.jam
warning: skipping optional Message Passing Interface (MPI) library.
note: to enable MPI support, add "using mpi ;" to user-config.jam.
note: to suppress this message, pass "--without-mpi" to bjam.
note: otherwise, you can safely ignore this message.
...patience...
...patience...
...patience...
...found 6637 targets...
...updating 8 targets...
darwin.compile.c++ bin.v2/libs/thread/build/darwin-4.5.0/release/threading-multi/pthread/thread.o

    "g++"  -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -dynamic -no-cpp-precomp -gdwarf-2 -std=c++0x -fPIC  -DBOOST_ALL_NO_LIB=1 -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_POSIX -DNDEBUG  -I"." -c -o "bin.v2/libs/thread/build/darwin-4.5.0/release/threading-multi/pthread/thread.o" "libs/thread/src/pthread/thread.cpp"

g++: unrecognized option '-no-cpp-precomp'
In file included from ./boost/thread/thread.hpp:22:0,
                 from libs/thread/src/pthread/thread.cpp:10:
./boost/thread/detail/thread.hpp: In function 'boost::thread&& boost::move(boost::thread&&)':
./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 ./boost/thread/detail/thread_heap_alloc.hpp:17:0,
                 from ./boost/thread/detail/thread.hpp:13,
                 from ./boost/thread/thread.hpp:22,
                 from libs/thread/src/pthread/thread.cpp:10:
./boost/thread/pthread/thread_heap_alloc.hpp: In function 'T* boost::detail::heap_new(A1&&) [with T = boost::detail::thread_data<void (*)()>, A1 = void (*&)()]':
./boost/thread/detail/thread.hpp:130:95:   instantiated from here
./boost/thread/pthread/thread_heap_alloc.hpp:24:47: error: cannot bind 'void (*)()' lvalue to 'void (*&&)()'
./boost/thread/detail/thread.hpp:43:13: error:   initializing argument 1 of 'boost::detail::thread_data<F>::thread_data(F&&) [with F = void (*)()]'
...failed darwin.compile.c++ bin.v2/libs/thread/build/darwin-4.5.0/release/threading-multi/pthread/thread.o...
...skipped <pstage/lib>libboost_thread.dylib for lack of <pbin.v2/libs/thread/build/darwin-4.5.0/release/threading-multi>pthread/thread.o...
...skipped <pbin.v2/libs/thread/build/darwin-4.5.0/release/threading-multi>libboost_thread.dylib for lack of <pbin.v2/libs/thread/build/darwin-4.5.0/release/threading-multi>pthread/thread.o...
...skipped <pstage/lib>libboost_wave.dylib for lack of <pbin.v2/libs/thread/build/darwin-4.5.0/release/threading-multi>libboost_thread.dylib...
darwin.compile.c++ bin.v2/libs/thread/build/darwin-4.5.0/release/link-static/threading-multi/pthread/thread.o

    "g++"  -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -no-cpp-precomp -gdwarf-2 -std=c++0x  -DBOOST_ALL_NO_LIB=1 -DBOOST_THREAD_BUILD_LIB=1 -DBOOST_THREAD_POSIX -DNDEBUG  -I"." -c -o "bin.v2/libs/thread/build/darwin-4.5.0/release/link-static/threading-multi/pthread/thread.o" "libs/thread/src/pthread/thread.cpp"

g++: unrecognized option '-no-cpp-precomp'
In file included from ./boost/thread/thread.hpp:22:0,
                 from libs/thread/src/pthread/thread.cpp:10:
./boost/thread/detail/thread.hpp: In function 'boost::thread&& boost::move(boost::thread&&)':
./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 ./boost/thread/detail/thread_heap_alloc.hpp:17:0,
                 from ./boost/thread/detail/thread.hpp:13,
                 from ./boost/thread/thread.hpp:22,
                 from libs/thread/src/pthread/thread.cpp:10:
./boost/thread/pthread/thread_heap_alloc.hpp: In function 'T* boost::detail::heap_new(A1&&) [with T = boost::detail::thread_data<void (*)()>, A1 = void (*&)()]':
./boost/thread/detail/thread.hpp:130:95:   instantiated from here
./boost/thread/pthread/thread_heap_alloc.hpp:24:47: error: cannot bind 'void (*)()' lvalue to 'void (*&&)()'
./boost/thread/detail/thread.hpp:43:13: error:   initializing argument 1 of 'boost::detail::thread_data<F>::thread_data(F&&) [with F = void (*)()]'
...failed darwin.compile.c++ bin.v2/libs/thread/build/darwin-4.5.0/release/link-static/threading-multi/pthread/thread.o...
...skipped <pbin.v2/libs/thread/build/darwin-4.5.0/release/link-static/threading-multi>libboost_thread.a(clean) for lack of <pbin.v2/libs/thread/build/darwin-4.5.0/release/link-static/threading-multi>pthread/thread.o...
...skipped <pbin.v2/libs/thread/build/darwin-4.5.0/release/link-static/threading-multi>libboost_thread.a for lack of <pbin.v2/libs/thread/build/darwin-4.5.0/release/link-static/threading-multi>pthread/thread.o...
...skipped <pstage/lib>libboost_thread.a for lack of <pbin.v2/libs/thread/build/darwin-4.5.0/release/link-static/threading-multi>libboost_thread.a...
...failed updating 2 targets...
...skipped 6 targets...
bash-3.2# 

Can you attach the preprocessed source? This might be an issue with boost.  There was a change with respect to rvalue references; lvalues cannot bind to rvalue references.  The C++0x standard is changing still so this was a change with the standard between the releases of 4.4 and 4.5.

Subject: Re:  Compiler flags error: error: invalid
 initialization of reference of type 'boost::thread&&' from expression of type
 'boost::thread'

Its attached.  /Michah
> 
> 
> ------- Comment #2 from pinskia at gcc dot gnu dot org  2010-04-28 02:00 -------
> Can you attach the preprocessed source? This might be an issue with boost. 
> There was a change with respect to rvalue references; lvalues cannot bind to
> rvalue references.  The C++0x standard is changing still so this was a change
> with the standard between the releases of 4.4 and 4.5.
> 
> 
> -- 
> 
> pinskia at gcc dot gnu dot org changed:
> 
>           What    |Removed                     |Added
> ----------------------------------------------------------------------------
>             Status|UNCONFIRMED                 |WAITING
> 
> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43915
> 
> ------- You are receiving this mail because: -------
> You are on the CC list for the bug, or are watching someone who is.
> You reported the bug, or are watching the reporter.

Created attachment 20502 [details]
Bzip'ed preprocessor output for "libs/thread/src/pthread/thread.cpp"  with    "g++" -c -save-temps  -std=c++0x ...

Bzip'ed thread.ii.

I think this error is correct:

./boost/thread/pthread/thread_heap_alloc.hpp: In function 'T*
boost::detail::heap_new(A1&&) [with T = boost::detail::thread_data<void (*)()>,
A1 = void (*&)()]':
./boost/thread/detail/thread.hpp:130:95:   instantiated from here
./boost/thread/pthread/thread_heap_alloc.hpp:24:47: error: cannot bind 'void
(*)()' lvalue to 'void (*&&)()'
./boost/thread/detail/thread.hpp:43:13: error:   initializing argument 1 of
'boost::detail::thread_data<F>::thread_data(F&&) [with F = void (*)()]'

A1 is deduced as an lvalue-reference, so reference-collapsing means that static_cast<A1&&> is a cast to an lvalue-reference, which won't bind to the rvalue-reference parameter.

And I also think this error is correct:

./boost/thread/detail/thread.hpp: In function 'boost::thread&&
boost::move(boost::thread&&)':
./boost/thread/detail/thread.hpp:349:16: error: invalid initialization of
reference of type 'boost::thread&&' from expression of type 'boost::thread'

Although the diagnostic is misleading. The code is:

    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)

I think this is INVALID

In this diagnostic:

invalid initialization of reference of type 'boost::thread&&' from expression of type 'boost::thread'

it might be clearer if the latter type was given as 'boost::thread&' so that it's clear it is an lvalue, otherwise it looks like it is failing to bind an rvalue-reference to a temporary, which should work.

In fact it's try to bind the reference to an lvalue, which is invalid

N.B. I stopped testing boost trunk against gcc trunk ages ago and I don't think anyone does it these days, which means that boost releases often don't work with GCC versions that come out after the release, especially if they are using the experimental C++0x support.  According to http://www.boost.org/users/news/version_1_42_0 Boost 1.42 was not tested with anything newer than 4.4.3 so it's unsurprising it doesn't use the new rvalue-reference rules that 4.5.0 implements

This should be reported as a bug against Boost

(In reply to comment #6)
> In this diagnostic:
> 
> invalid initialization of reference of type 'boost::thread&&' from expression
> of type 'boost::thread'
> 
> it might be clearer if the latter type was given as 'boost::thread&' so that
> it's clear it is an lvalue, otherwise it looks like it is failing to bind an
> rvalue-reference to a temporary, which should work.

Even better, the diagnostic could say "... from lvalue expression of type ..."

Any change should probably wait until the dust settles on the lvalue/xvalue/prvalue taxonomy

Appended status to booost bug 3944  http://svn.boost.org/trac/boost/ticket/3844

I don't think we need to suspend this, it's not possible to return an rvalue-reference bound to an lvalue, the code is invalid.

The following shows how to patch, compile and use boost 1.43.0 with g++ -std=c++0x.  At issue are the rvalue references and typecasts in the boost threading libraries.  Simply tell Boost not to use its rvalue reference code when it gets compiled, even with option std=c++0x is set.  Here's how:


1. Modify operatingSystem.jam, to compile with the -std=c+0x option.  Also, remove the -no-cpp-precomp option
if it is not supported by your compiler.  For OS X  I changed tools/build/v2/tools/darwin.jam at line 483 like this
# Misc options.
#flags darwin.compile OPTIONS : -no-cpp-precomp -gdwarf-2 ;
flags darwin.compile OPTIONS : -std=c++0x -gdwarf-2 ;


2. Modify gcc.hpp to disable the conditional compilation of rvalue references (temporarily, until that part of the code works with g++)
diff gcc.hpp.orig gcc.hpp
124c124,125
# define BOOST_HAS_RVALUE_REFS
// # define BOOST_HAS_RVALUE_REFS
# define BOOST_NO_RVALUE_REFERENCES

In this manner you can compile and use Boost 1.43 fine gcc 4.5 or earlier, and still build your software to use the c++0x features supported by the gnu copmiler option -std=c++0x. 

(In reply to comment #11)
> 
> 2. Modify gcc.hpp to disable the conditional compilation of rvalue references
> (temporarily, until that part of the code works with g++)
> diff gcc.hpp.orig gcc.hpp
> 124c124,125
> # define BOOST_HAS_RVALUE_REFS
> // # define BOOST_HAS_RVALUE_REFS
> # define BOOST_NO_RVALUE_REFERENCES

Or you can do it without editing the boost headers by defining BOOST_COMPILER_CONFIG to refer to a modified version ofthe gcc.hpp header