Let's talk about deprecations

[Vladimir Panteleev via Digitalmars-d]

On Sunday, 2 July 2017 at 23:27:26 UTC, Seb wrote:
> 1) Stop making such a fuzz about having a long deprecation 
> period. Most people will only care about a deprecation when 
> their project doesn't compile anymore. A deprecation period of 
> two releases is more than enough for users that care. As seen 
> even _eight_ releases don't help! (std.c was deprecated in 
> 2.067)

Long deprecation periods are really useful for situations where 
you need to support a wide range of compiler frontend versions 
(e.g. DMD and GDC, or whatever ancient D version is packaged on 
Debian/CentOS stable). They're also very helpful for regression 
testing, as you don't have to add static ifs all over just to 
test if the same otherwise effectively identical code worked in 
older compilers.

Once the relevant symbols are deprecated and removed from 
documentation, they have almost no cost, so there is no pressure 
to remove them quickly. I think overall it's more useful to leave 
old stuff around for longer rather than shorter amounts of time.