struct Foo(Copyable):
    var s: String

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

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

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

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

comptime __copy_ctor_is_trivial

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

A copy constructor is considered to be trivial if:

• The struct has a compiler-generated trivial copy constructor because all its fields have trivial copy constructors.

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

comptime __move_ctor_is_trivial

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

The implementation of a move constructor is considered to be trivial if:

• The struct has a compiler-generated trivial move constructor because all its fields have trivial move constructors.

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

__init__(out self: _Self, *, copy: _Self)

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

Args:

• ​copy (_Self): The value to copy.

Returns:

_Self

__init__(out self: _Self, *, deinit take: _Self)

Create a new instance of the value by moving the value of another.

Args:

• ​take (_Self): The value to move.

Returns:

_Self

copy(self: _Self) -> _Self

Explicitly construct a copy of self, a convenience method for Self(copy=self) when the type is inconvenient to write out.

Returns:

_Self: A copy of this value.