Function
Functions in Swift are distinguishable by
- parameter label
- parameter type
- return type
so that these are all valid, and works for subscript as well
struct A {
// return type
func get() -> String { return "" }
func get() -> Int { return 1 }
// mix of parameter type and return type
func get(param: String) -> String { return "" }
func get(param: String) -> Int { return 1 }
func get(param: Int) -> Int { return 1 }
func get(param: Int) -> String { return "" }
subscript(param: String) -> String { return "" }
subscript(param: String) -> Int { return 1 }
subscript(param: Int) -> Int { return 1 }
subscript(param: Int) -> String { return "" }
// parameter label
func set(int: Int) {}
func set(string: String) {}
// concrete type from generic
func get(param: Array<String>) -> String { return "" }
func get(param: Array<Int>) -> Int { return 1 }
subscript(param: Array<String>) -> String { return "" }
subscript(param: Array<Int>) -> Int { return 1 }
}
When you specialize a generic type, like Array<Int>, you're actually using a concrete type
Unfortunately, this does not work for NSObject subclass
Method 'get()' with Objective-C selector 'get' conflicts with previous declaration with the same Objective-C selector
class B: NSObject {
func get() -> String { return "" }
func get() -> Int { return 1 }
}
Generic function
We can overload generic functions as well
func f<T>(t: T) {
print("T")
}
func f(string: String) {
print("String")
}
func f(int: Int) {
print("Int")
}
Original post https://github.com/onmyway133/blog/issues/211
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