Re: [boost] [smart_ptr] !defined(BOOST_NO_CXX11_SMART_PTR) does notimply !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)

Michel Morin wrote:

`!defined(BOOST_NO_CXX11_SMART_PTR)` does not necessarily mean that the compiler support of rvalue references is available. For example,

How could the standard library have std::unique_ptr without the compiler supporting rvalue references?

when I use shared_ptr (on trunk) with clang + libc++ in a C++03 mode, I get warnings something like

boost/smart_ptr/shared_ptr.hpp:556:51: warning: rvalue references are a C++11 extension [-Wc++11-extensions] shared_ptr & operator=( std::unique_ptr<Y, D> && r )

Looks like rvalue references are available, but as an extension.