# Pastebin uN7C7h2i
Red on  master [$?] via 🐳 orbstack via 🦋 v6.d-moar
λ RAKUDO_RAKUAST=1 raku -e '

class Expression { method Str { self } }

multi infix:<~>(Str() $left, Expression $right) { "SQL concat" }

say "prefix: { Expression.new }";

'
This type cannot unbox to a native string: P6opaque, Expression
  in block <unit> at -e line 7

Red on  master [$?] via 🐳 orbstack via 🦋 v6.d-moar
λ RAKUDO_RAKUAST=1 raku -e '

class Expression is Str { method Str { self } }

multi infix:<~>(Str() $left, Expression $right) { "SQL concat" }

say "prefix: { Expression.new }";

'
prefix:
Red on  master [$?] via 🐳 orbstack via 🦋 v6.d-moar
λ RAKUDO_RAKUAST=1 raku -e '

class Expression { method Str { "expression" } }

multi infix:<~>(Str() $left, Expression $right) { "SQL concat" }

say "prefix: { Expression.new }";

'
prefix: expression
Red on  master [$?] via 🐳 orbstack via 🦋 v6.d-moar
λ