IntPair Subset

IntPair.pl6

subset IntPair of Pair where {
    die "Key $_.key() is not an Int" unless val($_.key.Str) ~~ Int;
    die "Value $_.value() is not an Int" unless .value ~~ Int;
    True
}

my IntPair @edges =
    1 => 2,
    3 => 4,
    6 => 2;

sub foo(IntPair @e) { say @e }

foo(@edges)

Solved! Thanks @zoffixznet!