Re: [boost] Boost and auto_ptr (was Boost 1.60.0 beta 1...)

Subject: Re: [boost] Boost and auto_ptr (was Boost 1.60.0 beta 1...)
From: Stephan T. Lavavej (stl_at_[hidden])
Date: 2015-11-11 15:29:22

[Gavin Lambert]
> I suspect though that if it's not removed at some point, then people 
> will continue using it incorrectly; this was probably a factor in the 
> committee's decision to remove it rather than merely leaving it 
> deprecated, and similarly for MS following suit.

Yes.

Regardless of how individual Boost developers may feel about the issue:

1. auto_ptr/etc. have been removed from the C++17 Working Paper. It's done, they're gone, and they're not coming back. (They were deprecated in C++11/14, so National Bodies can't object - that is the very meaning of deprecation.)

2. Implementations are migrating - GCC is emitting deprecation warnings, and VC is moving towards outright removal.

3. On the other side, Boost should respect the wishes of programmer-users who wish to migrate early (e.g. compiling with /D_HAS_AUTO_PTR_ETC=0).

Therefore, Boost should stop using auto_ptr/etc. The mechanism for doing so is up to you (conditioning on toolset version is probably the way to go, possibly with escape hatches). Supporting leading-edge toolsets in this manner should be no different than supporting the old toolsets that Boost already goes to great effort for.

Stephan T. Lavavej
Senior Developer - Visual C++ Libraries