Enumerable.Range to return a custom object with fast value enumerator

[WhiteBlackGoose]

Enumerable.Range currently returns IEnumerable<int> whose enumerator is implemented on reference types and virtual calles.

I suggest, instead, returning a value type, whose enumerator would also be a value type. Thanks to inlining it may almost reach the naive implementation of for loop, and hence, it would be much easier to use Enumerable.Range in foreach loops.

Thoughts?

[stephentoub]

Return type is part of a method's signature. Changing this would be a binary breaking change.
https://github.com/dotnet/runtime/blob/main/docs/coding-guidelines/breaking-change-rules.md#signatures

[WhiteBlackGoose]

I see. But then wouldn't it make sense to add Enumerable.ValueRange for the same purpose but fast one?

I managed to make value enumerator as fast as for-loop (under some circumstances), whereas the current Enumerable.Range works 15 times slower.

[stephentoub]

I don't personally think it adds enough value. Just write a for loop. LINQ is about composition with other enumerables and combinators.

[WhiteBlackGoose]

Hm. Since it will only improve the experience with foreach, this indeed may not be very useful, thanks for replies!