introduce const in instruction and register modules

[i509VCB]

Start of the series in #237 but in no way the end of it.

[wtfsck]

When would the decoder ever run in a const context? Since it uses lazy static that should never be possible.

[i509VCB]

Well the only things const in decoder are related to querying the state of some fields on decoder, the actual construction or decoding can't be const because of lazy static.

[wtfsck]

Yes but AFAIK it's not possible to use those functions in a const context since the whole expression (including the creation of the decoder) must be evaluated in a const context. IOW, this shouldn't even be possible:

let decoder = create it;
const X: Y = decoder.some_const_fn();

Since that's not possible ,there should be no reason to make any decoder fns const.

[wtfsck]

Start of the series in #237 but in no way the end of it.

Do you plan on pushing more commits or will you create more PRs? If you plan on pushing more commits, you can update the first post saying Closes #237 to it gets auto closed when this gets merged!

[i509VCB]

Well it's going to be more pull requests in the future. Some of them are going to need higher rust version dependencies while others may need some internal changes.

[wtfsck]

Well it's going to be more pull requests in the future. Some of them are going to need higher rust version dependencies while others may need some internal changes.

I'm not ready to bump the MSRV yet though. I did that not long ago. 1.48.0 was released only a year ago.

[i509VCB]

I've made sure this builds locally with 1.48

[wtfsck]

Thanks!