Trait openexr::core::refptr::OpaquePtr[−][src]

pub unsafe trait OpaquePtr {
    type SysPointee;
    type Pointee;
}
Expand description

This trait describes the relationship between an opaque pointer to a C++ object and the newtype we use to wrap it in Rust.

This trait is unsafe to implement because the associated types are used as parameters to transmute() in the Ref and RefMut wrappers, so getting this wrong would be very bad.

To be specific, SysPointee must be the pointee C++ type and Pointee must be the newtype wrapper, which must be #[repr(transparent)]. For example, for Header:

#[repr(transparent)] pub struct Header(pub(crate) *mut sys::Imf_Header_t);

the SysPointee is sys::Imf_Header_t and Pointee is Header and this is valid because Header is a transparent newtype of sys::Imf_Header_t

Associated Types

Implementors