Get the name (string) of a generic type in Swift
You can return any types' name by using string interpolation:
class MyClass<T> {
func genericName() -> String {
return "\(T.self)"
}
}
You can try it in a playground and it works as expected:
var someClass = MyClass<String>()
someClass.genericName() // Returns "Swift.String"
String(describing: T.self)
in Swift 3+
var genericTypeName: String {
return String(describing: T.self)
}
Within the generic type, get the name of type T
by converting T.self
or type(of: T.self)
to a String
. I found that type(of:)
was not necessary but it's worth being aware of since in other cases it removes other details about the Type.
The following example demonstrates getting the name of the generic type T
within a struct and a class. It includes code to get the name of the containing type.
Example including class and struct
struct GenericStruct<T> {
var value: T
var genericTypeName: String {
return String(describing: T.self)
}
var genericTypeDescription: String {
return "Generic Type T: '\(genericTypeName)'"
}
var typeDescription: String {
// type(of:) is necessary here to exclude the struct's properties from the string
return "Type: '\(type(of: self))'"
}
}
class GenericClass<T> {
var value: T
var genericTypeName: String {
return String(describing: T.self)
}
var genericTypeDescription: String {
return "Generic Type T: '\(genericTypeName)'"
}
var typeDescription: String {
let typeName = String(describing: self)
return "Type: '\(typeName)'"
}
init(value: T) {
self.value = value
}
}
enum TestEnum {
case value1
case value2
case value3
}
let intGenericStruct: GenericStruct<Int> = GenericStruct(value: 1)
print(intGenericStruct.typeDescription)
print(intGenericStruct.genericTypeDescription)
let enumGenericStruct: GenericStruct<TestEnum> = GenericStruct(value: .value2)
print(enumGenericStruct.typeDescription)
print(enumGenericStruct.genericTypeDescription)
let intGenericClass: GenericClass<Int> = GenericClass(value: 1)
print(intGenericClass.typeDescription)
print(intGenericClass.genericTypeDescription)
let enumGenericClass: GenericClass<TestEnum> = GenericClass(value: .value2)
print(enumGenericClass.typeDescription)
print(enumGenericClass.genericTypeDescription)
Console Output
/*
Type: 'GenericStruct<Int>'
Generic Type T: 'Int'
Type: 'GenericStruct<TestEnum>'
Generic Type T: 'TestEnum'
Type: 'GenericClass<Swift.Int>'
Generic Type T: 'Int'
Type: 'GenericClass<TestEnum>'
Generic Type T: 'TestEnum'
*/