Trait cpp_utils::UnsafeStaticCast

pub trait UnsafeStaticCast<T> {
    unsafe fn static_cast(&self) -> &T;
    unsafe fn static_cast_mut(&mut self) -> &mut T;
}

Provides access to C++ static_cast conversion from base class to derived class.

This trait is automatically implemented by cpp_to_rust. If T1 class is derived (in C++) from T2 class, UnsafeStaticCast<T1> is implemented for T2.

UnsafeStaticCast allows to convert a reference to a class into a reference to a derived class without runtime check of the type. Casting from base class type to a derived class type which is not the actual type of the object will result in an invalid reference.

unsafe_static_cast and unsafe_static_cast_mut free functions can be used to convert pointer types.

Note that Rust functions associated with this trait have runtime overhead. In C++, static_cast is usually a no-op if there is no multiple inheritance, and multiple inheritance requires pointer adjustment. However, Rust compiler and cpp_to_rust do not have any information about these implementation details, so all calls of static_cast are wrapper in FFI functions. Still, static_cast is faster than casts with runtime checks on C++ side because runtime overhead of Rust wrapper functions is the same for all cast types.

Required Methods

unsafe fn static_cast(&self) -> &T

Convert type of a const reference.

unsafe fn static_cast_mut(&mut self) -> &mut T

Convert type of a mutable reference.

Implementors