Trait MakeCppStorage

pub unsafe trait MakeCppStorage: Sized {
    // Required methods
    unsafe fn allocate_uninitialized_cpp_storage() -> *mut Self;
    unsafe fn free_uninitialized_cpp_storage(ptr: *mut Self);
}

A type which has the ability to create heap storage space for itself in C++, without initializing that storage.

Safety

Implementers must ensure that the pointer returned by allocate_uninitialized_cpp_storage is a valid, non-null, pointer to a new but uninitialized storage block, and that such blocks must be freeable using either of these routes:

• before they’re initialized, using free_uninitialized_cpp_storage
• after they’re initialized, via a delete expression like delete p;

Required Methods

unsafe fn allocate_uninitialized_cpp_storage() -> *mut Self

Allocates heap space for this type in C++ and return a pointer to that space, but do not initialize that space (i.e. do not yet call a constructor).

Safety

To avoid memory leaks, callers must ensure that this space is freed using free_uninitialized_cpp_storage, or is converted into a UniquePtr such that it can later be freed by std::unique_ptr<T, std::default_delete<T>>.

unsafe fn free_uninitialized_cpp_storage(ptr: *mut Self)

Frees a C++ allocation which has not yet had a constructor called.

Safety

Callers guarantee that the pointer here was allocated by allocate_uninitialized_cpp_storage and has not been initialized.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors