[Boost-users] [Boost.Move] Conflict between std::move and boost::move (Boost 1.49.0)

Subject: [Boost-users] [Boost.Move] Conflict between std::move and boost::move (Boost 1.49.0)
From: Jonathan Jones (Jonathan.Jones_at_[hidden])
Date: 2012-07-10 17:18:19

Hi folks,

Consider the following code (which distilled from a real world example):

#include <boost/move/move.hpp>
#include <boost/optional/optional.hpp>
#include <utility>
#include <vector>

typedef boost::optional<int> data_type;
typedef std::vector<data_type> vector_type;

vector_type func()
{
    vector_type vv;
    return move(vv);
}

If I compile this code using Boost 1.49 on Visual Studio 2010, or on a recent version of g++ (e.g. 4.7.1) which supports some C++11 features, the code fails to compile, complaining about ambiguity between std::move and boost::move.  Strangely, the code compiles fine with Apple Clang version 3.1.

Is there a way to work around the compilation problem which doesn't involve explicitly qualifying the calls to move?  I'd prefer to use argument-dependent-lookup.  Removing the includes of boost/move.hpp is not possible.  In the real world example, that header is included indirectly.

I did notice that if I define the macro BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE, the compilation errors disappear.  Is this the correct approach for compilers which support std::move?  I find it odd that this macro isn't already defined for such compilers.

Thanks in advance!
Jon