std::ops::Place

Trait std::ops::Place

pub trait Place<Data> where    Data: ?Sized, {
    fn pointer(&mut self) -> *mut Data;
}

Both PLACE <- EXPR and box EXPR desugar into expressions that allocate an intermediate "place" that holds uninitialized state. The desugaring evaluates EXPR, and writes the result at the address returned by the pointer method of this trait.

A Place can be thought of as a special representation for a hypothetical &uninit reference (which Rust cannot currently express directly). That is, it represents a pointer to uninitialized storage.

The client is responsible for two steps: First, initializing the payload (it can access its address via pointer). Second, converting the agent to an instance of the owning pointer, via the appropriate finalize method (see the InPlace.

If evaluating EXPR fails, then it is up to the destructor for the implementation of Place to clean up any intermediate state (e.g. deallocate box storage, pop a stack, etc).

Required Methods

Implementors

• impl<'a, T> Place<T> for BinaryHeapPlace<'a, T> where
    T: Clone + Ord, 
• impl<'a, T> Place<T> for FrontPlace<'a, T>
• impl<'a, T> Place<T> for BackPlace<'a, T>
• impl<'a, T> Place<T> for std::vec::PlaceBack<'a, T>
• impl<'a, T> Place<T> for std::collections::vec_deque::PlaceBack<'a, T>
• impl<'a, T> Place<T> for PlaceFront<'a, T>
• impl<T> Place<T> for IntermediateBox<T>
• impl<'a, K, V> Place<V> for EntryPlace<'a, K, V>