Re: [boost] [smart_ptr] make_shared perfect forwarding bug

Subject: Re: [boost] [smart_ptr] make_shared perfect forwarding bug
From: Peter Dimov (pdimov_at_[hidden])
Date: 2009-04-18 19:21:35

Frank Mori Hess:
> Perfect forwarding doesn't seem to work quite correctly with 
> boost::make_shared.  The attached program, which tries to pass a move-only 
> type through make_shared fails to compile with gcc in c++0x mode.  To fix 
> it, I had to change the definition of detail::forward in make_shared.hpp 
> to use rvalue references:
>
> #if defined( BOOST_HAS_RVALUE_REFS )
> template< class T > T&& forward( T &&t )
> {
>     return t;
> }
> #endif
>
> This is just based on looking at how gcc implements std::forward.  Is this 
> the right fix?

Yes, I believe so. My original forward was incorrect. (We should probably 
switch to std::forward at some point.)