Re: [boost] Deprecation and Boost

From: Jeff Garland (jeff_at_[hidden])
Date: 2006-05-07 17:36:46

Nicola Musatti wrote:

> I don't agree. Why remove a support that is there and has been through 
> several Boost releases? I understand that library authors wishing to 
> evolve their libraries are entitled to choose which compilers they plan 
> t osupport and the amount of effort they wish to devote to supporting 
> obsolete compilers, but if it works, why break it?

Because, I have to maintain several versions of code that have the 
potential for different bugs.  In date_time the from_string/to_string 
methods were written early on and were carefully crafted to work with 
VC6, Borland, etc.  Even now, like yesterday actually, a new failure 
mode will show up in these functions.  In the meantime, I've completely 
rewritten the i/o subsystem -- it's much more flexible and robust.  It 
supports wide chars, is heavy on templates, and breaks on a bunch of old 
compilers -- basically it's disabled on all the legacy compilers.

Now I could trivially rewrite the from_string/to_string using the new 
i/o code and fix any issues in one place, but I can't do it without 
breaking old compiler support.  In addition, I have a second variant of 
i/o code on the old compilers to maintain and fix bugs for. And last, 
but not least, the only reason date_time isn't header-only at this point 
is the legacy i/o code.

So all of this is a big pain for me and that's why I'm so vocal about 
this release being the end of the line for date_time support of old 
compilers and standard libraries.  When I look at the global boost 
situation it pains me to see library authors dedicated to defining and 
evolving the future of C++ spending their time trying to make these 
non-compliant tools work.  Every minute they spend adjusting for the old 
compilers is a minute taken away from something better for the future of 
C++ programmers overall. It's my judgment overall that we've crossed 
over the line where it's far better for us to focus on the future rather 
than the past.  A Boost-wide deprecation of the old compilers/standard 
libs takes the brakes off the forward progress.

BTW, as a little note of history, when I first used Boost 5 or 6 years 
ago now, many of the libraries were only 'marginally portable' -- mostly 
because typical compilers of the day were VC6 and g++ 2.93.  All sorts 
of libraries broke different compilers in different ways.  The standard 
libraries of the day were mostly just bad. Now we have a whole breed of 
excellent compilers/standard libs that will compile and run a much 
larger collection of Boost libraries.  This is a huge leap forward from 
where we were.  I believe part of that progress was brought about by 
Boost "pushing things" forward.  The way I see it, without Boost 
continuing to push, much of the life would come out of the C++ 
evolution.  I want to maximize the push now because we still have much 
work to do.

Jeff