CollectionsMarshal.GetValueRef(Dictionary) - #49388

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Still needs doc comments and tests

Are there places outside of Dictionary we should be using the new method, too?

Are there places outside of Dictionary we should be using the new method, too?

For GetValueRef the big wins are for struct TValues; either using in place or mutating which don't look to be a common pattern in CoreLib.

However GetValueRefOrAddDefault does look like it would have more applicability removing a double lookup from TryGet+Add; assuming it was implemented more efficiently. So is probably worth looping back and doing that as well.

GetValueRefOrAddDefault does look like it would have more applicability removing a double lookup from TryGet+Add

It also needs to be something reasonably hot to make it worth the trouble.

It also needs to be something reasonably hot to make it worth the trouble.

While CoreLib does create dictionaries, it doesn't really do much modifying of them and alas my search-fu isn't good enough to check all the other libs; though I definitely have uses further downstream

Looks like a ref enumerator

ref struct RefEnumerator
{
    (TKey key, ref TValue) Current { get; }
    bool MoveNext();
}

would be helpful too, but small steps 😉

Thanks, @benaadams.

runtime (Libraries Test Run checked coreclr windows x64 Debug) Failure is #48236 though that's closed, and looks like the vm pool died for the rest

Rebased to reset CI

🥳