[PyQt] Request for Comments: Support for C++ Scoped Enums

[Phil Thompson]

On 11 Aug 2017, at 5:56 pm, Shaheed Haque <srhaque at theiet.org> wrote:
> 
> On 11 August 2017 at 16:22, Phil Thompson <phil at riverbankcomputing.com> wrote:
> At the moment SIP only supports C-like unscoped enums and implements them as sub-classes of int. The main weaknesses of these are the lack of type safety and the injection of the member names into the enclosing scope.
> 
> These problems were fixed by the introduction of scoped enums in newer versions of C++, see...
> 
> https://www.ibm.com/developerworks/rational/library/scoped-enums/index.html
> 
> Note that Qt doesn't currently use scoped enums but I expect that to change.
> 
> Scoped enums are much closer to the implementation of Python enums...
> 
> https://docs.python.org/3/library/enum.html#module-enum
> 
> I propose to add support for scoped enums and implement them using Python enums - specifically as sub-classes of Enum (and *not* IntEnum in order to preserve the type safety). Consequently Python v3.4 or later will be required for wrapping libraries using scoped enums.
> 
> Any comments welcome.
> 
> Phil
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> My present focus is on Python2.7, and though I am keen to move onto 3, that's perhaps some weeks/months off. So, if there is some basic support for 2, that would allow me to transition in my own time.

I'll make sure any error message prompts the user to install...

https://pypi.python.org/pypi/enum34/

...but only because it is easy to do. I'm not promising to support Python2 for any new features. I don't see why you would want to want to target Python2 for a new (and substantial) package.

Phil