[swift-dev] Simple question about ParameterTypeFlags

David Zarzycki dave at znu.io
Mon Dec 11 15:15:03 CST 2017


Hello! I’m trying to test which ParameterTypeFlags flag combinations are valid. I wrote the following test case. Are the results “as expected”, or are some of the failures incorrect?

// RUN: %target-typecheck-verify-swift


//
// isVariadic is NOT compatible with any flag combinations
//
// expected-error at +1 {{@autoclosure must not be used on variadic parameters}}
func v_and_autoclosure(arg : @autoclosure ()->()...) {}
// expected-error at +1 {{@escaping attribute may only be used in function parameter position}}
func v_and_escaping(arg : @escaping ()->()...) {}
// expected-error at +1 {{'inout' must not be used on variadic parameters}}
func v_and_inout(arg : inout Int...) {}
// expected-error at +1 {{'__shared' must not be used on variadic parameters}}
func v_and_shared(arg : __shared Int...) {}

//
// 'inout' is NOT compatible with remaining parameter flag combinations
//
// expected-error at +1 {{parameter must not have multiple '__owned', 'inout', '__shared', 'var', or 'let' specifiers}}
func inout_and_shared(arg : inout __shared Int) {}
// expected-error at +1 {{'inout' may only be used on parameters}}
func inout_and_escaping(arg : @escaping inout ()->()) {}
// expected-error at +1 {{@escaping attribute may only be used in function parameter position}}
func escaping_and_inout(arg : inout @escaping ()->()) {}
// expected-error at +1 {{@autoclosure may only be used on parameters}}
func inout_and_autoclosure(arg : inout @autoclosure ()->()) {}
// expected-error at +1 {{'inout' may only be used on parameters}}
func autoclosure_and_inout(arg : @autoclosure inout ()->()) {}

//
// '__shared' is NOT compatible with remaining parameter flag combinations
//
// expected-error at +1 {{'__shared' may only be used on parameters}}
func autoclosure_and_shared(arg : @autoclosure __shared ()->()) {}
// expected-error at +1 {{@autoclosure may only be used on parameters}}
func shared_and_autoclosure(arg : __shared @autoclosure ()->()) {}
// expected-error at +1 {{'__shared' may only be used on parameters}}
func escaping_and_shared(arg : @escaping __shared ()->()) {}
// expected-error at +1 {{@escaping attribute may only be used in function parameter position}}
func shared_and_escaping(arg : __shared @escaping ()->()) {}

//
// @autoclosure and @escaping are the only valid parameter flag combinations
//
func autoclosure_and_escaping(arg : @autoclosure @escaping ()->()) {}
func escaping_and_autoclosure(arg : @escaping @autoclosure ()->()) {}


More information about the swift-dev mailing list