P2355R0: Postfix fold expressions
Fold expressions work with binary operators, but not with unary operators: you can write !!…!!x, but there’s still only one x. However, there are other kinds of operators to which they might apply. In particular, there are several plausible use cases for the postfix operators [ ] and ( ) (function call). This paper proposes extending the fold-expression syntax to support these two operators. The rationale for the syntactical structure is also presented.