Mojo trait

Copyable

The Copyable trait denotes a type whose value can be copied.

Example implementing the Copyable trait on Foo which requires the __copyinit__ method:

struct Foo(Copyable):
    var s: String

    fn __init__(out self, s: String):
        self.s = s

    fn __copyinit__(out self, other: Self):
        print("copying value")
        self.s = other.s

You can now copy objects inside a generic function:

fn copy_return[T: Copyable](foo: T) -> T:
    var copy = foo
    return copy

var foo = Foo("test")
var res = copy_return(foo)

copying value

Implemented traits

AnyType, ExplicitlyCopyable, UnknownDestructibility

Aliases

`copyinitis_trivial`

alias __copyinit__is_trivial

A flag (often compiler generated) to indicate whether the implementation of __copyinit__ is trivial.

The implementation of __copyinit__ is considered to be trivial if:

The struct has a compiler-generated trivial __copyinit__ and all its fields have a trivial __copyinit__ method.

In practice, it means the value can be copied by copying the bits from one location to another without side effects.

`delis_trivial`

alias __del__is_trivial

A flag (often compiler generated) to indicate whether the implementation of __del__ is trivial.

The implementation of __del__ is considered to be trivial if:

The struct has a compiler-generated trivial destructor and all its fields have a trivial __del__ method.

In practice, it means that the __del__ can be considered as no-op.

Methods

`copyinit`

__copyinit__(out self: _Self, existing: _Self, /)

Create a new instance of the value by copying an existing one.

Args:

existing (_Self): The value to copy.

Returns:

_Self

`copy`

copy(self: _Self) -> _Self

Explicitly construct a copy of self.

Returns:

_Self: A copy of this value.

Implemented traits​

Aliases​

__copyinit__is_trivial​

__del__is_trivial​

Methods​

__copyinit__​

copy​