There is one thing that seems really inconvenient to me but I'd
like to see community opinion before writing a DIP :) It is all
about current semantics of "deprecated" attribute.
Right now using deprecated symbols is a warning. And if you use
"-w" switch (like most pedantic projects do) it is an error that
halts the compilation. It is possible to use "-d" to avoid
breaking stuff but then it will just work silently, with no
message at all.
In practice, I tend to always apply the following deprecation
path:
1) Modify the code to print message about upcoming deprecation
(via pragma(msg))
2) On previously defined date mark symbol as deprecated and
define expected removal date
3) Remove it completely
It is very inconvenient to do manually but necessary to make
deprecation process smooth - initially I just want to make users
aware that some time should be scheduled to adjust their code in
future, without any interfering with normal compilation. Then do
actual deprecation that will result in an error but still provide
meaningful message about changes that need to be made. And only
after that removal is viable.
I'd really love to be able to provide date/time parameter in some
way to deprecate attribute and let compiler do all this routine
for me automatically - just print message (not a warning) if
compiled before the date, act as it does now after.
So far I have not found see any way to define a good deprecation
path with an existing toolset.
Opinions / recommendations?
