Empty Set literal syntax

Question

Looking for the right syntax or if there's a bug/rough edge:

Set{}

for empty hashes use '{} of KeyType => ValueType' <-wrong

Set{} of Char

expecting token '=>', not 'EOF' <-wrong

Set(Char){}

for empty hashes use '{} of KeyType => ValueType' <-wrong

Set(Char).new # not a literal

Set{'a'} # not an empty Set literal

Answer 1

There isn't one, use Set(Char).new.

Set literals, such as Set{'a'} actually compile to:

__tmp_var = Set(typeof('a')).new
__tmp_var << 'a'
__tmp_var

so there's no performance benefit to using an empty literal instead of Set(Char).new