nanocom 0.2.1

Nano-COM, extremly small subset of cross-platform COM
Documentation 
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use crate::{hresult::HRESULT, interface::Interface, iunknown::IUnknown, r#ref::Ref, vmt::Vmt};
use std::ptr::null;

#[repr(C)]
pub struct Object<I: 'static = ()>(&'static Vmt<I>);

impl<I> Object<I> {
    pub fn new(vmt: &'static Vmt<I>) -> Self {
        Self(vmt)
    }
    pub unsafe fn iunknown(&self) -> &'static IUnknown<I> {
        &self.0.iunknown
    }
    pub unsafe fn interface(&self) -> &'static I {
        &self.0.interface
    }
    pub fn to_iunknown(&self) -> &Object {
        let p = self as *const Object<I> as *const Object;
        unsafe { &*p }
    }
    pub fn query_interface<J: Interface>(&self) -> Result<Ref<J>, HRESULT> {
        let mut p = null();
        match unsafe { (self.0.iunknown.QueryInterface)(self, &J::GUID, &mut p) } {
            HRESULT::S_OK => {
                let r = p as *const Object<J>;
                Ok(unsafe { Ref::from_raw(r) })
            }
            e => Err(e),
        }
    }
    pub fn query_iunknown(&self) -> Ref {
        self.query_interface().unwrap()
    }
}