Re: [boost] Should the clang, c++11 and libstdc++ configuration supported?

Subject: Re: [boost] Should the clang, c++11 and libstdc++ configuration supported?
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2012-11-17 15:31:03

On 17/11/12 15:52, Daniel James wrote:
> On 17 November 2012 14:31, Peter Dimov <lists_at_[hidden]> wrote:
>> What parts of SmartPtr don't work with clang/libstdc++?
>
> There are calls to std::forward in
> boost/smart_ptr/make_shared_array.hpp, and
> boost/smart_ptr/allocate_shared_array.hpp that check for compiler
> support but not library support. I don't know if there's an
> appropriate config macro.

Personally I recommend avoiding std::forward, at least for code that 
needs to be compatible with other than the best and latest compilers. It 
adds an unnecessary dependency on a library component, is not very 
useful (static_cast<T&&>(t) looks essentially the same as 
std::forward<T>(t)), and it adds an uncessary function call, which means 
bloat and debugging annoyances.

> This is only an issue with older versions of libstdc++ in C++11 mode,
> so I don't think it's a common problem. I only came across it in
> Boost.Test because I was trying to recreate an error people were
> seeing. For normal development, I'd never do it.

It probably also affects other compilers that have C++11 but no C++11 
standard library, like xlC.