In role Buf§
See primary documentation in context for method reallocate.
method reallocate(Buf:D: Int:D $elems)
Change the number of elements of the Buf, returning the changed Buf. The size of Buf will be adapted depending on the number of $elems specified: if it is smaller than the actual size of the Buf the resulting Buf will be shrunk down, otherwise it will be enlarged to fit the number of $elems. In the case the Buf is enlarged, newly created items will be assigned a Virtual Machine specific null value, therefore you should not rely upon their value since it could be inconsistent across different virtual machines.
my Buf $bú .= new(^10); $bú.reallocate(5); say $bú.raku; # OUTPUT: «Buf.new(0,1,2,3,4)» $bú = Buf.new( 1..3 ); $bú.reallocate( 10 ); say $bú.raku; # OUTPUT: «Buf.new(1,2,3,0,0,0,0,0,0,0)»