On Monday, 21 December 2015 at 09:06:08 UTC, Shriramana Sharma
wrote:
http://dlang.org/spec/template.html#TemplateTupleParameter
Apart from the obvious need for changing the references to
tuples to alias sequences (for which I'm working on a PR), my
question:
Both the above page and http://dlang.org/phobos/std_meta.html
refer to "slicing" alias sequences. In D slicing means just
creating another reference to the same memory as the sliced
object.
Given that AliasSeq-s cannot be written to[*], it's not
possible for me to test whether it's actually sliced or a new
AliasSeq with the same elements is created. Otherwise I could
do something like this:
alias A = [int, 2, symbol];
alias B = A[1 .. $];
alias C = A[0 .. $ - 1];
A[1] = 3; // not possible
static assert(B[0] == 3 && C[1] == 3);
So out of curiosity I'd like to know how this is implemented in
the compiler: as really a slice or a copy? (Posting this to D
and not learn since it relates to compiler internals.)
I don't know the answer, but I suspect it's a (shallow) copy.
Anyway, as you've noticed, there's no observable difference
either way, so this is an implementation detail which the
documentation shouldn't mention (if this was the intention behind
your question).
