A little operator that lets you mutate an object in a one-liner without needing to use the mutator's return value!

mutator-tunnel-operator.p6

"foobarbaz".comb.Array.splice(3,1,"X").join.say;
# Output: b

# Issue: splice returns what was cut out, not the result.

# Solution: Keep the array of characters around for later.
my @a = "foobarbaz".comb; @a.splice(3,1,"X"); @a.join.say;
# Output: fooXarbaz

# Don't want to introduce a local variable for this?

# Use this beautiful operator to apply a mutation to
# the variable and return the mutated value, rather than
# the mutator's return value
sub postcircumfix:<⦓ ⦔>($a, &code) { my $b = $a; code($a); $b };

# et voilà!
"foobarbaz".comb.Array⦓*.splice(3,1,"X")⦔.join.say;
# Output: fooXarbaz