Opaque Over Existential Parameter

Prefer opaque over existential type in function parameter

• Identifier: opaque_over_existential
• Enabled by default: No
• Supports autocorrection: Yes
• Kind: lint
• Analyzer rule: No
• Minimum Swift compiler version: 5.0.0
• Default configuration:

  Key	Value
  severity	warning

Non Triggering Examples

func f(_: some P) {}

func f(_: (some P)?) {}

func f(_: some P & Q) {}

func f(_: any P.Type) {}

func f(_: (any P.Type)?) {}

func f(_: borrowing any ~Copyable.Type) {}

func f(_: () -> Int = { let i: any P = p(); return i.get() }) {}

func f(_: [any P]) {}

func f(_: [any P: any Q]) {}

func f(_: () -> any P) {}

Triggering Examples

func f(_: ↓any P) {}

func f(_: (↓any P)?) {}

func f(_: ↓any P & Q) {}

func f(_: borrowing ↓any ~Copyable) {}

func f(_: borrowing (↓any ~Copyable)?) {}

func f(_: (↓any P, ↓any Q)) {}