PhantomContravariantLifetime in std::marker - Rust (original) (raw)

Struct PhantomContravariantLifetime

Source

pub struct PhantomContravariantLifetime<'a>(/* private fields */);

🔬This is a nightly-only experimental API. (phantom_variance_markers #135806)

Expand description

Zero-sized type used to mark a lifetime as contravariant.

Contravariant lifetimes must live at most as long as declared. See the reference for more information.

§Layout

For all 'a, the following are guaranteed:

• size_of::<PhantomContravariantLifetime<'a>>() == 0
• align_of::<PhantomContravariantLifetime<'a>>() == 1

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Source

🔬This is a nightly-only experimental API. (phantom_variance_markers #135806)

Constructs a new instance of the variance marker.

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