show how to slip a complex Hash into named arguments

Author: gfldex

doc/Type/Signature.pod6

@@ -453,12 +453,21 @@ L<Pair|/type/Pair> with C<|> to turn it into a named argument.
     my $pair = :named(1);
     f |$pair;                               # «(:$named)␤»
 
-The same can be used to convert a Hash into named arguments.
+The same can be used to convert a C<Hash> into named arguments.
 
     my %pairs = also-named => 4;
     sub f(|c) {};
     f |%pairs;                              # «(:$also-named)␤»
 
+A C<Hash> that contains a list may prove problematic when slipped into named
+arguments. To avoid the extra layer of containers coerce to L<Map|/type/Map>
+before slipping.
+
+    class C { has $.x; has $.y; has @.z };
+    my %h = <x y z> Z=> (5, 20, [1,2]);
+    say C.new(|%h.Map);
+    # OUTPUT«C.new(x => 5, y => 20, z => [1, 2])␤»
+
 X<|optional argument (Signature)>
 =head2 Optional and Mandatory Parameters