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https://github.com/denoland/rusty_v8.git
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update
This commit is contained in:
Bert Belder
parent
fdfa52f4bf
commit
48db2272ca
3
.rustfmt.toml
Normal file
3
.rustfmt.toml
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@ -0,0 +1,3 @@
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# Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
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max_width = 80
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tab_spaces = 2
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405
src/main.rs
405
src/main.rs
@ -1,246 +1,249 @@
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mod channel {
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use super::util;
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use super::util;
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extern "C" {
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// Call a method/destructor; virtual methods use C++ dynamic dispatch.
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fn Channel__DTOR(this: &mut Channel) -> ();
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fn Channel__a(this: &mut Channel) -> ();
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fn Channel__b(this: &Channel) -> i32;
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extern "C" {
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// Call a method/destructor; virtual methods use C++ dynamic dispatch.
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fn Channel__DTOR(this: &mut Channel) -> ();
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fn Channel__a(this: &mut Channel) -> ();
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fn Channel__b(this: &Channel) -> i32;
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// Call a method of a specific class implementation, bypassing dynamic
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// dispatch. C++ equivalent: `my_channel.Channel::a()`.
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fn Channel__Channel__a(this: &mut Channel) -> ();
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// Call a method of a specific class implementation, bypassing dynamic
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// dispatch. C++ equivalent: `my_channel.Channel::a()`.
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fn Channel__Channel__a(this: &mut Channel) -> ();
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// Constructs a special class derived from Channel that forwards all
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// virtual method invocations to rust. It is assumed that this subclass
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// has the same size and memory layout as the class it's deriving from.
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fn Channel__OVERRIDE__CTOR(this: &mut std::mem::MaybeUninit<Channel>) -> ();
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// Constructs a special class derived from Channel that forwards all
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// virtual method invocations to rust. It is assumed that this subclass
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// has the same size and memory layout as the class it's deriving from.
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fn Channel__OVERRIDE__CTOR(this: &mut std::mem::MaybeUninit<Channel>)
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-> ();
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}
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#[repr(C)]
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pub struct Channel {
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_cxx_vtable: *const [usize; 0],
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}
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#[allow(dead_code)]
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impl Channel {
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pub fn a(&mut self) {
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unsafe { Channel__a(self) }
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}
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pub fn b(&self) -> i32 {
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unsafe { Channel__b(self) }
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}
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}
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impl Drop for Channel {
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fn drop(&mut self) {
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unsafe { Channel__DTOR(self) }
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}
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}
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pub struct ChannelDefaults;
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impl ChannelDefaults {
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pub fn a(this: &mut Channel) {
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unsafe { Channel__Channel__a(this) }
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}
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}
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pub trait ChannelOverrides {
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fn extender(&self) -> &ChannelExtender;
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fn extender_mut(&mut self) -> &mut ChannelExtender;
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fn a(&mut self) {
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ChannelDefaults::a(self.extender_mut())
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}
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fn b(&self) -> i32;
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}
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pub struct ChannelExtender {
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cxx_channel: Channel,
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extender_offset: usize,
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rust_vtable: util::RustVTable<&'static dyn ChannelOverrides>,
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}
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#[no_mangle]
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unsafe extern "C" fn Channel__OVERRIDE__a__DISPATCH(this: &mut Channel) {
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ChannelExtender::dispatch_mut(this).a()
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}
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#[no_mangle]
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unsafe extern "C" fn Channel__OVERRIDE__b__DISPATCH(this: &Channel) -> i32 {
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ChannelExtender::dispatch(this).b()
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}
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impl ChannelExtender {
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fn construct_cxx_channel() -> Channel {
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unsafe {
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let mut buf = std::mem::MaybeUninit::<Channel>::uninit();
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Channel__OVERRIDE__CTOR(&mut buf);
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buf.assume_init()
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}
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}
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#[repr(C)]
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pub struct Channel {
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_cxx_vtable: *const [usize; 0],
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fn get_extender_offset<T>() -> usize
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where
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T: ChannelOverrides,
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{
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let buf = std::mem::MaybeUninit::<T>::uninit();
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let embedder_ptr: *const T = buf.as_ptr();
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let self_ptr: *const Self = unsafe { (*embedder_ptr).extender() };
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util::FieldOffset::from_ptrs(embedder_ptr, self_ptr).offset()
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}
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#[allow(dead_code)]
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impl Channel {
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pub fn a(&mut self) {
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unsafe { Channel__a(self) }
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}
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pub fn b(&self) -> i32 {
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unsafe { Channel__b(self) }
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}
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fn get_rust_vtable<T>() -> util::RustVTable<&'static dyn ChannelOverrides>
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where
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T: ChannelOverrides,
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{
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let buf = std::mem::MaybeUninit::<T>::uninit();
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let embedder_ptr = buf.as_ptr();
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let trait_object: *const dyn ChannelOverrides = embedder_ptr;
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let (data_ptr, vtable): (*const T, util::RustVTable<_>) =
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unsafe { std::mem::transmute(trait_object) };
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assert_eq!(data_ptr, embedder_ptr);
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vtable
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}
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pub struct ChannelDefaults;
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impl ChannelDefaults {
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pub fn a(this: &mut Channel) {
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unsafe { Channel__Channel__a(this) }
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}
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pub fn new<T>() -> Self
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where
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T: ChannelOverrides,
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{
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Self {
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cxx_channel: Self::construct_cxx_channel(),
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extender_offset: Self::get_extender_offset::<T>(),
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rust_vtable: Self::get_rust_vtable::<T>(),
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}
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}
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pub trait ChannelOverrides {
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fn base(&self) -> &Override;
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fn base_mut(&mut self) -> &mut Override;
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fn a(&mut self) {
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ChannelDefaults::a(self.base_mut())
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}
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fn b(&self) -> i32;
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fn channel_offset() -> util::FieldOffset<Self, Channel> {
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let buf = std::mem::MaybeUninit::<Self>::uninit();
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util::FieldOffset::from_ptrs(buf.as_ptr(), unsafe {
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&(*buf.as_ptr()).cxx_channel
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})
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}
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pub struct Override {
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cxx_channel: Channel,
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base_offset: usize,
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rust_vtable: util::RustVTable<&'static dyn ChannelOverrides>,
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fn embedder_offset(&self) -> util::FieldOffset<util::Opaque, Self> {
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util::FieldOffset::<util::Opaque, Self>::from_offset(self.extender_offset)
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}
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#[no_mangle]
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unsafe extern "C" fn Channel__OVERRIDE__a__DISPATCH(this: &mut Channel) {
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Override::dispatch_mut(this).a()
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}
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#[no_mangle]
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unsafe extern "C" fn Channel__OVERRIDE__b__DISPATCH(this: &Channel) -> i32 {
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Override::dispatch(this).b()
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unsafe fn dispatch(channel: &Channel) -> &dyn ChannelOverrides {
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let this = Self::channel_offset().to_outer(channel);
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let embedder = this.embedder_offset().to_outer(this);
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std::mem::transmute((embedder, this.rust_vtable))
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}
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impl Drop for Channel {
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fn drop(&mut self) {
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unsafe { Channel__DTOR(self) }
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}
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unsafe fn dispatch_mut(channel: &mut Channel) -> &mut dyn ChannelOverrides {
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let this = Self::channel_offset().to_outer_mut(channel);
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let vtable = this.rust_vtable;
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let embedder = this.embedder_offset().to_outer_mut(this);
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std::mem::transmute((embedder, vtable))
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}
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}
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impl Override {
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fn construct_cxx_channel() -> Channel {
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unsafe {
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let mut buf = std::mem::MaybeUninit::<Channel>::uninit();
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Channel__OVERRIDE__CTOR(&mut buf);
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buf.assume_init()
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}
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}
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fn get_base_offset<T>() -> usize
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where
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T: ChannelOverrides,
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{
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let buf = std::mem::MaybeUninit::<T>::uninit();
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let top_ptr: *const T = buf.as_ptr();
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let self_ptr: *const Self = unsafe { (*top_ptr).base() };
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util::FieldOffset::from_ptrs(top_ptr, self_ptr).offset()
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}
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fn get_rust_vtable<T>() -> util::RustVTable<&'static dyn ChannelOverrides>
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where
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T: ChannelOverrides,
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{
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let buf = std::mem::MaybeUninit::<T>::uninit();
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let embedder_ptr = buf.as_ptr();
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let trait_object: *const dyn ChannelOverrides = embedder_ptr;
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let (data_ptr, vtable): (*const T, util::RustVTable<_>) =
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unsafe { std::mem::transmute(trait_object) };
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assert_eq!(data_ptr, embedder_ptr);
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vtable
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}
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pub fn new<T>() -> Self
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where
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T: ChannelOverrides,
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{
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Self {
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cxx_channel: Self::construct_cxx_channel(),
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base_offset: Self::get_base_offset::<T>(),
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rust_vtable: Self::get_rust_vtable::<T>(),
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}
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}
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fn channel_offset() -> util::FieldOffset<Self, Channel> {
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let buf = std::mem::MaybeUninit::<Self>::uninit();
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util::FieldOffset::from_ptrs(buf.as_ptr(), unsafe { &(*buf.as_ptr()).cxx_channel })
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}
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fn embedder_offset(&self) -> util::FieldOffset<util::Opaque, Self> {
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util::FieldOffset::<util::Opaque, Self>::from_offset(self.base_offset)
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}
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unsafe fn dispatch(channel: &Channel) -> &dyn ChannelOverrides {
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let this = Self::channel_offset().to_outer(channel);
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let embedder = this.embedder_offset().to_outer(this);
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std::mem::transmute((embedder, this.rust_vtable))
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}
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unsafe fn dispatch_mut(channel: &mut Channel) -> &mut dyn ChannelOverrides {
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let this = Self::channel_offset().to_outer_mut(channel);
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let vtable = this.rust_vtable;
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let embedder = this.embedder_offset().to_outer_mut(this);
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std::mem::transmute((embedder, vtable))
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}
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impl std::ops::Deref for ChannelExtender {
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type Target = Channel;
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fn deref(&self) -> &Channel {
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&self.cxx_channel
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}
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}
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impl std::ops::Deref for Override {
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type Target = Channel;
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fn deref(&self) -> &Channel {
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&self.cxx_channel
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}
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}
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impl std::ops::DerefMut for Override {
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fn deref_mut(&mut self) -> &mut Channel {
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&mut self.cxx_channel
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}
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impl std::ops::DerefMut for ChannelExtender {
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fn deref_mut(&mut self) -> &mut Channel {
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&mut self.cxx_channel
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}
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}
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}
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mod trying {
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use super::channel::*;
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use super::channel::*;
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#[allow(dead_code)]
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pub struct Session {
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a: i32,
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b: String,
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c: Override,
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}
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#[allow(dead_code)]
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pub struct Session {
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a: i32,
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b: String,
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c: ChannelExtender,
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}
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impl ChannelOverrides for Session {
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fn base(&self) -> &Override {
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&self.c
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}
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fn base_mut(&mut self) -> &mut Override {
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&mut self.c
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}
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fn a(&mut self) {
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println!("Override a!");
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}
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fn b(&self) -> i32 {
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println!("Override b!");
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42
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}
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impl ChannelOverrides for Session {
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fn extender(&self) -> &ChannelExtender {
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&self.c
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}
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fn extender_mut(&mut self) -> &mut ChannelExtender {
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&mut self.c
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}
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fn a(&mut self) {
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println!("ChannelExtender a!");
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}
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fn b(&self) -> i32 {
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println!("ChannelExtender b!");
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42
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}
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}
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impl Session {
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pub fn new() -> Self {
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Self {
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a: 1,
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b: "abc".to_owned(),
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c: Override::new::<Self>(),
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}
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}
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impl Session {
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pub fn new() -> Self {
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Self {
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a: 1,
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b: "abc".to_owned(),
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c: ChannelExtender::new::<Self>(),
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}
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}
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}
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}
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mod util {
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use std::marker::PhantomData;
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use std::mem::size_of;
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use std::marker::PhantomData;
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use std::mem::size_of;
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pub type Opaque = [usize; 0];
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pub type Opaque = [usize; 0];
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#[repr(transparent)]
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#[derive(Copy, Clone, Debug)]
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pub struct RustVTable<DynT>(pub *const Opaque, pub PhantomData<DynT>);
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#[repr(transparent)]
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#[derive(Copy, Clone, Debug)]
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pub struct RustVTable<DynT>(pub *const Opaque, pub PhantomData<DynT>);
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#[derive(Copy, Clone, Debug)]
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#[repr(transparent)]
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pub struct FieldOffset<O, I>(isize, PhantomData<(O, I)>);
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#[derive(Copy, Clone, Debug)]
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#[repr(transparent)]
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pub struct FieldOffset<O, I>(isize, PhantomData<(O, I)>);
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impl<O, I> FieldOffset<O, I> {
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pub fn from_ptrs(o_ptr: *const O, i_ptr: *const I) -> Self {
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let o_addr = o_ptr as usize;
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let i_addr = i_ptr as usize;
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assert!(i_addr >= o_addr);
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assert!((i_addr + size_of::<I>()) <= (o_addr + size_of::<O>()));
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let offset = (o_addr - i_addr) as isize;
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assert!(offset > 0);
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Self(offset, PhantomData)
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}
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pub fn from_offset(offset: usize) -> Self {
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assert!((offset as isize) > 0);
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Self(offset as isize, PhantomData)
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}
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pub fn offset(self) -> usize {
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self.0 as usize
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}
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fn shift<PI, PO>(ptr: *const PI, delta: isize) -> *mut PO {
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(ptr as isize + delta) as *mut PO
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}
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pub unsafe fn to_outer<'a>(&self, inner: &'a I) -> &'a O {
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Self::shift::<I, O>(inner, -self.0).as_ref().unwrap()
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}
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#[allow(dead_code)]
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pub unsafe fn to_outer_mut<'a>(&self, inner: &'a mut I) -> &'a mut O {
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Self::shift::<I, O>(inner, -self.0).as_mut().unwrap()
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}
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impl<O, I> FieldOffset<O, I> {
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pub fn from_ptrs(o_ptr: *const O, i_ptr: *const I) -> Self {
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let o_addr = o_ptr as usize;
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let i_addr = i_ptr as usize;
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assert!(i_addr >= o_addr);
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assert!((i_addr + size_of::<I>()) <= (o_addr + size_of::<O>()));
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let offset = (o_addr - i_addr) as isize;
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assert!(offset > 0);
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Self(offset, PhantomData)
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}
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impl<O, M, I> std::ops::Add<FieldOffset<M, I>> for FieldOffset<O, M> {
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type Output = FieldOffset<O, I>;
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fn add(self, that: FieldOffset<M, I>) -> Self::Output {
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FieldOffset::<O, I>::from_offset(self.offset() + that.offset())
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}
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pub fn from_offset(offset: usize) -> Self {
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assert!((offset as isize) > 0);
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Self(offset as isize, PhantomData)
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}
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pub fn offset(self) -> usize {
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self.0 as usize
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}
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fn shift<PI, PO>(ptr: *const PI, delta: isize) -> *mut PO {
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(ptr as isize + delta) as *mut PO
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}
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pub unsafe fn to_outer<'a>(&self, inner: &'a I) -> &'a O {
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Self::shift::<I, O>(inner, -self.0).as_ref().unwrap()
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}
|
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#[allow(dead_code)]
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pub unsafe fn to_outer_mut<'a>(&self, inner: &'a mut I) -> &'a mut O {
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Self::shift::<I, O>(inner, -self.0).as_mut().unwrap()
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}
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}
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impl<O, M, I> std::ops::Add<FieldOffset<M, I>> for FieldOffset<O, M> {
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type Output = FieldOffset<O, I>;
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fn add(self, that: FieldOffset<M, I>) -> Self::Output {
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FieldOffset::<O, I>::from_offset(self.offset() + that.offset())
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}
|
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}
|
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}
|
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|
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fn main() {
|
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trying::Session::new();
|
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trying::Session::new();
|
||||
}
|
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|
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