Details
Description
Swift standard library contains examples of prefix and postfix operators followed by infix-operator-group (see https://docs.swift.org/swift-book/ReferenceManual/Declarations.html#grammar_operator-declaration), even though the official specification disallows it.
For example:
postfix operator ... : Comparable prefix operator ! : Bool prefix operator ~ : BinaryInteger prefix operator + : AdditiveArithmetic prefix operator - : SignedNumeric prefix operator ... : Comparable prefix operator ..< : Comparable
One of the early usages:
https://github.com/apple/swift/pull/20659/files
Might be related to https://github.com/apple/swift-evolution/blob/master/proposals/0077-operator-precedence.md