From @zoffixznet

several combinations of Whatever and Callable candidates that are present in Array.splice are missing from Buf.splice. I think for consistency reasons, both variants should offer the same collection of candidates​:

[ZoffixW] m​: my @​a = <1 2 3>; @​a.splice​: *, *, <42 72>; say @​a
[camelia] rakudo-moar 5d909c​: OUTPUT«[1 2 3 42 72]␤»
[ZoffixW] m​: my $b = Buf.new​: <1 2 3>; $b.splice​: *, *, <42 72>; say $b
[camelia] rakudo-moar 5d909c​: OUTPUT«Cannot resolve caller splice(Buf​: Whatever, Whatever, List); none of these signatures match​:␤ (Buf​:D \SELF​: *%_)␤ (Buf​:D $​: Int $offset, $size = Whatever, *%_)␤ (Buf​:D $​: Int $offset, $size, int $got, *%_)␤ (Buf​:D $​: Int $offset, $size,…»

From @zoffixznet

<Zoffix> After a day of hacking on this, I think I'm going to reject https://rt-archive.perl.org/perl6/Ticket/Display.html?id=129358
<Zoffix> Bufs have a bit different candidates in that they take native int arrays, or other Bufs, and they replacement arrays need to have int things in them. So basically exact match between Array.splice and Buf.spice won't happen.
<Zoffix> That leaves to adding Callable and Whatever candidates to Buf.splice, but IMO that's overengineering, and the 31 candidates for Arrays.splice are telling of that.
<Zoffix> So I'm going to reject that ticket, until there's any reasonable usecase for why Buf.splice needs Callable/Whatever candidates.

http://irclog.perlgeek.de/perl6-dev/2016-10-02#i_13322672

@zoffixznet - Status changed from 'new' to 'rejected'