is duplicated by:

• SR-5578 Partial key paths don't provide enough type context to omit the base of a key path literal
• SR-6740 KeyPath: should infer class from argument types
• SR-8382 Contextual typing for key path literals in PartialKeyPath context doesn't work.
• SR-8383 Can't infer Root type of key path expression for PartialKeyPath parameter
• SR-12390 Cannot use shorthand key path syntax on PartialKeyPath argument
• SR-14549 Function call gives an error "Type of expression is ambiguous without more context".

relates to:

• SR-5217 Protocol creates ambiguity around KeyPath roots

Issue Description:

struct Parameters {
    var orderByDate: Bool?
}

let key: PartialKeyPath<Parameters> = \.orderByDate // works!
let keys: [PartialKeyPath<Parameters>] = [\.orderByDate] // ambiguous :(