Re: [boost] A possible date for dropping c++03 support

Subject: Re: [boost] A possible date for dropping c++03 support
From: Edward Diener (eldiener_at_[hidden])
Date: 2018-08-26 18:12:18

On 8/26/2018 8:53 AM, Peter Dimov via Boost wrote:
> Edward Diener wrote:
> 
>> My objection to the usual Boost "dropping C++03 support" is that there 
>> is absolutely no reason for forcing libraries which do support C++03, 
>> while being usable at any higher C++ standard level, to do anything.
> 
> Boost dropping C++03 support means just that, we announce that Boost no 
> longer supports C++03. Individual libraries may or may not continue to 
> support it, but f.ex. trying "b2 install" with a C++03 compiler will no 
> longer be expected to work.

What do you mean that it will no longer be "expected to work" with some 
individual library ? We already have that for plenty of libraries that 
will not work unless the level of support is C++11 or above. But this is 
because compile errors will result if you compile the library in C++03 
mode. Are you saying that b2 should be changed so that it detects if it 
is being invoked with a C++ standard C++03 level and will therefore put 
out a b2 error message instead of continuing ? Even if that were true 
that will only affect running tests and building docs for such a library 
if the library is a header-only library, and since the end-user of a 
distribution hardly needs to build docs it will only affect running 
tests for a header-only library.

> 
> We could then consider building with -std=c++11 by default on g++ 
> 4.8/4.9, and with -std=c++14 by default on g++5 and possibly clang 
> (although clang c++14 doesn't quite work with libstdc++ 4.x so that'd be 
> a problem).

At least that is a practical proposal, but of course does not affect 
header-only libraries.