parameter_types! helper functions should be uniform across modes

[liamaharon]

The parameter_types works in 3 modes.

1. static (generates thread_local stuff)
2. storage
3. const

All of which generate a Get implementation, backed by something, along some other helper functions like get, set, mutate and take (kinda similar to storage items..).

It seemed to me that the set of helper functions that is generated by parameter_types! is not uniform across different modes.

If interested, you can convert this comment into an issue and self-assign.

Originally posted by @kianenigma in #13794 (comment)

[ggwpez]

We and dowstream projects use those in many spots. Just having a breaking change here for beauty is not that of a good idea IMHO.
Unless we can stay backwards compatible. Maybe we can give all of them storage traits?

[bkchr]

It seemed to me that the set of helper functions that is generated by parameter_types! is not uniform across different modes.

You can not give all of them uniform functions. const for example can not be set/mutated/taken. The static implementation for example also can not be "taken".

[kianenigma]

What I originally suggested is entirely backwards compatible. It seemed that some functions are missing, and adding them would make the API more uniform.

[bkchr]

And which are missing?

[liamaharon]

From what I could gather, these are the differences in mode:

• const: Generates a const getter function named get.

• No prefix (non-const): Generates a non-const getter function named get.

• storage: Generates getter and setter functions. It also generates a key function to get the storage key.

• static: Generates getter and setter functions. It also generates thread_local code.

The differences in API between seem irreconcilable at first glance, e.g. it doesn't make sense for const to have a setter, or for the static mode to have a key.

[bkchr]

The differences in API between seem irreconcilable at first glance, e.g. it doesn't make sense for const to have a setter, or for the static mode to have a key.

As I tried to explain above.

[kianenigma]

Got it, I have jumped too fast at making it an issue them. Thanks for the explanation(s), closing.