Trait std::ops::Place
[−]
[src]
pub trait Place<Data> where Data: ?Sized {
fn pointer(&mut self) -> *mut Data;
}placement_new_protocol)Both in (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 the destructor for the implementation of Place to clean up any intermediate state (e.g. deallocate box storage, pop a stack, etc).
Required Methods
fn pointer(&mut self) -> *mut Data
placement_new_protocol)Returns the address where the input value will be written.
Note that the data at this address is generally uninitialized,
and thus one should use ptr::write for initializing it.
Implementors
impl<T> Place<T> for IntermediateBox<T>impl<'a, T> Place<T> for FrontPlace<'a, T>impl<'a, T> Place<T> for BackPlace<'a, T>impl<'a, T> Place<T> for PlaceBack<'a, T>