Perl 6:maxpairs警告未定义值的字符串化

看起来像 maxpairs

> my @foo; @foo[2] = 4; say @foo.maxpairs;
Use of uninitialized value of type Any in string context.
Methods .^name, .perl, .gist, or .say can be used to stringify it to something meaningful.
  in block <unit> at <unknown file> line 1

(2 => 4)

max 没有相同的问题,似乎只是忽略未定义的值:

> my @foo; @foo[2] = 4; say @foo.max;
4

> my @foo; @foo[2] = 4; say @foo.pairs.max(*.value)
Use of uninitialized value of type Any in string context.
Methods .^name, .perl, .gist, or .say can be used to stringify it to something meaningful.
  in block <unit> at <unknown file> line 1

2 => 4

因此,似乎只有在使用时才会忽略未定义的值 没有过滤器参数。

这是虫子吗?