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If you try to build bits with base-4.16 (bundled with GHC 9.2), you'll get this error:

[1 of 3] Compiling Data.Bits.Extras ( src/Data/Bits/Extras.hs, interpreted )

src/Data/Bits/Extras.hs:210:39: error:
    Ambiguous occurrence ‘oneBits’
    It could refer to
       either ‘Data.Bits.oneBits’,
              imported from ‘Data.Bits’ at src/Data/Bits/Extras.hs:34:1-16
           or ‘Data.Bits.Extras.oneBits’,
              defined at src/Data/Bits/Extras.hs:204:1
    |
210 | srl b n = (b `shiftR` n) .&. rotateR (oneBits `shiftL` n) n
    |                                       ^^^^^^^

This is because Data.Bits now defines a function named oneBits as well. It is almost the same as the oneBits function defined in Data.Bits.Extras, but with one key difference—Data.Bits' oneBits has a FiniteBits constraint, while Data.Bits.Extras' oneBits has a Bits constraint. Note that some functions currently rely on the weaker Bits constraint (e.g., Data.Bits.Extras.srl), so the two are not interchangeable.

How should we address this? I see two possibilities:

1. Hide Data.Bits' oneBits when importing it throughout bits and continue defining Data.Bits.Extras' version separately.
2. Re-export Data.Bits' oneBits when building with base-4.16 or later, and on older versions of base, define a compatibility shim for oneBits with a FiniteBits constraint.

I'd personally prefer possibility (2), although that would require a breaking change.