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opaque handle

A pointer the other side may pass around but never look inside.

An opaque handle is a pointer to a type the foreign side can't see the layout of; only the owning library's functions create, use, and free it.

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Examples

  • Box::into_raw(Box::new(playlist)) hands C a *mut Playlist it can't look inside; C passes it back to a free function that calls Box::from_raw once.

See also

foreign function interface raw pointer ownership
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