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Sized
The Sized trait describes a type that has an integer length (such as a string or array).
Any type that conforms to Sized or
SizedRaising works with the
built-in len() function.
The Sized trait requires a type to implement the __len__()
method. For example:
@fieldwise_init
struct Foo(Sized):
var length: Int
def __len__(self) -> Int:
return self.length
You can pass an instance of Foo to the len() function to get its
length:
@fieldwise_init
struct Foo(Sized):
var length: Int
def __len__(self) -> Int:
return self.length
var foo = Foo(42)
print(len(foo) == 42)
True
Note: If the __len__() method can raise an error, use the
SizedRaising trait instead.