[JEP Proposal] Constant-Time Enum Size Access (https://gist.github.com/TuranDev/9a20c773d8c698de918da54b2964bf65)

[Turan Suleyman]

Hi all,
I’d like to start a discussion/gather feedback about a "small" quality of life enhancement to java.lang.Enum to add a constant-time, allocation-free way to obtain the number of constants in an enum type.
Today, the usual approach is: int n = MyEnum.values().length;
This creates a new array on every call, which is both non-constant time and allocates memory unnecessarily.
Since the number of enum constants is fixed and known at compile time, this information could be exposed more efficiently.
I’ve written a draft JEP describing two possible designs:

- A compiler-generated static constant, e.g.
public static final int SIZE = <number of constants>;
- A built-in API method such as
MyEnum.size();

Draft JEP: https://gist.github.com/TuranDev/9a20c773d8c698de918da54b2964bf65
I’d appreciate feedback on:

- Whether this seems like a worthwhile enhancement
- Preference between the two design options
- Whether anyone would be interested in sponsoring the JEP ( or rolling the change into an open piece of work) if there’s agreement to pursue it.

Thank you for your time and thoughts.
Best regards,Turan
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