Feature flags

[CEXT-Dan]

Not to be confused with user configuration, but I think it would be nice to have feature development switches. I prefer to do trunk dev, continuous code review, continuous behavior resting.
How can we keep the trunk green, but have the ability to just enable features
Since I added a toml reader in C++, maybe C++ and Python can share feature tags.

def isMyNewFeatureEnabled():
    pass # look up some value in a toml

def foo():
    if(isMyNewFeatureEnabled()):
        pass# do this
    else:
        pass# do that

[gswifort]

I can't keep up, please be clearer 😄

[CEXT-Dan]

example

feature .toml
per-user-config = 1

_host_init.py
def foo()
    if feature_service[per-user-config]:
        do_new_feature_stuff()
    else
        do_stuff_the_old_way

I would do the same in C++

on release to pypi, features that are not ready would be set to 0
or have feature .toml ignored, feature_service would return false

This would enable developers to change behavior at runtime instead of switching to a branch and having to recompile

[gswifort]

Ok, but assuming we're about to finish working on #289, maybe there should be a separate section for enabling features there?

[CEXT-Dan]

Right not for #289, throwing out ideas for the next “feature”.
I’ll goof around with this and see what works from a C++ perspective and post my findings