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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
use deno_core::v8;use std::mem::transmute;use std::ops::Deref;use std::os::raw::c_void;use std::ptr::NonNull;
/// An FFI-opaque, nullable wrapper around v8::Local<v8::Value>./// rusty_v8 Local handle cannot be empty but napi_value can be.#[repr(transparent)]#[derive(Clone, Copy, Debug)]pub struct NapiValue<'s>(  Option<NonNull<v8::Value>>,  std::marker::PhantomData<&'s ()>,);
pub type napi_value<'s> = NapiValue<'s>;
impl<'s> Deref for napi_value<'s> {  type Target = Option<v8::Local<'s, v8::Value>>;  fn deref(&self) -> &Self::Target {    // SAFETY: It is safe to transmute `Option<NonNull<T>>` to `Option<*const T>`.    //         v8::Local guarantees that *const T is not null but napi_value *can* be null.    unsafe { transmute::<&Self, &Self::Target>(self) }  }}
impl<'s, T> From<v8::Local<'s, T>> for napi_value<'s>where  v8::Local<'s, T>: Into<v8::Local<'s, v8::Value>>,{  fn from(v: v8::Local<'s, T>) -> Self {    // SAFETY: It is safe to cast v8::Local<T> that implements Into<v8::Local<v8::Value>>.    //         `fn into(self)` transmutes anyways.    Self(unsafe { transmute(v) }, std::marker::PhantomData)  }}
const _: () = {  assert!(    std::mem::size_of::<napi_value>() == std::mem::size_of::<*mut c_void>()  );  // Assert "nullable pointer optimization" on napi_value  unsafe {    type Src<'a> = napi_value<'a>;    type Dst = usize;    assert!(std::mem::size_of::<Src>() == std::mem::size_of::<Dst>());    union Transmute<'a> {      src: Src<'a>,      dst: Dst,    }    Transmute {      src: NapiValue(None, std::marker::PhantomData),    }    .dst  };};