From tomentiruran@gmail.com

my @​h is default([])
[]
@​h[0].push​: 3
[3]
@​h
[]
@​h[0]
[3]

my %h is default({})
{}
%h<a><b> = 3
3
%h
{}
%h<a>
{b => 3}

The array/hash variable's default is an empty array/hash literal. If an element is autovivified, it can be accessed directly, but isn’t findable from the variable.

From @AlexDaniel

Heh.

FWIW we had this since forever​: https://gist.github.com/Whateverable/78168042a011e01fc768c042b0d91898

On 2017-09-09 19​:53​:53, tomentiruran@​gmail.com wrote​:

my @​h is default([])
[]
@​h[0].push​: 3
[3]
@​h
[]
@​h[0]
[3]

my %h is default({})
{}
%h<a><b> = 3
3
%h
{}
%h<a>
{b => 3}

The array/hash variable's default is an empty array/hash literal. If
an element is autovivified, it can be accessed directly, but isn’t
findable from the variable.

The RT System itself - Status changed from 'new' to 'open'

From @jnthn

On Sat, 09 Sep 2017 19​:53​:53 -0700, tomentiruran@​gmail.com wrote​:

my @​h is default([])
[]
@​h[0].push​: 3
[3]
@​h
[]
@​h[0]
[3]

my %h is default({})
{}
%h<a><b> = 3
3
%h
{}
%h<a>
{b => 3}

The array/hash variable's default is an empty array/hash literal. If
an element is autovivified, it can be accessed directly, but isn’t
findable from the variable.

While I suspect this can be fixed (and is missing setup of the auto-viv callback on the codepath for setting up a default), note that `is default` is a trait, it is evaluated at compile time. Thus there is one single array that will be shared globally and assigned into all elements, which probably isn't what you wanted.

/jnthn