stable_deref_trait 1.2.1

# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
version = 4

[[package]]
name = "sample-stable-deref-trait"
version = "1.0.0"
dependencies = [
 "stable_deref_trait",
]

[[package]]
name = "stable_deref_trait"
version = "1.2.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6ce2be8dc25455e1f91df71bfa12ad37d7af1092ae736f3a6cd0e37bc7810596"

[package]
name = "sample-stable-deref-trait"
version = "1.0.0"
edition = "2021"
publish = false

[dependencies]
stable_deref_trait = "=1.2.1"

[[bin]]
name = "contract"
path = "test/contract.rs"

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:cargo/stable_deref_trait@1.2.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:cargo/stable_deref_trait@1.2.1

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:b23251b62df45e2912bb688dca21050832a0c89a15774cc7df17a199ab5956c8","contract":["StableDeref is implemented for standard heap container types Box, Vec, and String","CloneStableDeref is implemented for shared reference types Rc, Arc, and immutable references","CloneStableDeref guarantees that cloned instances dereference to the identical memory address","StableDeref is implemented for interior mutability cell guards Ref and RefMut","Custom container types can implement StableDeref to preserve dereference target stability across moves"],"goal":"verify pkg:cargo/stable_deref_trait@1.2.1","kind":"HOW","packages":["pkg:cargo/stable_deref_trait@1.2.1"],"schemaVersion":1},"contractCommand":["cargo","run","--offline"],"environment":{"arch":"x64","distro":"alpine","ecosystem":"cargo","libc":"musl","os":"linux","packageManager":"cargo","schemaVersion":1},"license":"MIT-0","packages":["pkg:cargo/stable_deref_trait@1.2.1"],"schemaVersion":1,"subject":"pkg:cargo/stable_deref_trait@1.2.1","verifierAdapter":"cargo@1"}

{
  "schemaVersion": 1,
  "goal": "verify pkg:cargo/stable_deref_trait@1.2.1",
  "kind": "HOW",
  "packages": [
    "pkg:cargo/stable_deref_trait@1.2.1"
  ]
}

//! Clean-room verification sample for stable_deref_trait.

pub use stable_deref_trait::*;

use std::cell::RefCell;
use std::ops::Deref;
use std::rc::Rc;
use std::sync::Arc;
use stable_deref_trait::{CloneStableDeref, StableDeref};

fn assert_stable_deref<T: StableDeref>(_val: &T) {}
fn assert_clone_stable_deref<T: CloneStableDeref>(_val: &T) {}

struct CustomBox<T>(Box<T>);
impl<T> Deref for CustomBox<T> {
    type Target = T;
    fn deref(&self) -> &Self::Target {
        &self.0
    }
}
unsafe impl<T> StableDeref for CustomBox<T> {}

fn main() {
    // 1. StableDeref is implemented for standard heap container types Box, Vec, and String
    let b = Box::new(42);
    let v = vec![1, 2, 3];
    let s = String::from("stable_deref_trait");
    assert_stable_deref(&b);
    assert_stable_deref(&v);
    assert_stable_deref(&s);

    // 2. CloneStableDeref is implemented for shared reference types Rc, Arc, and immutable references
    let rc = Rc::new(100);
    let arc = Arc::new(200);
    let val = 300;
    let r = &val;
    assert_clone_stable_deref(&rc);
    assert_clone_stable_deref(&arc);
    assert_clone_stable_deref(&r);

    // 3. CloneStableDeref guarantees that cloned instances dereference to the identical memory address
    let rc_clone = rc.clone();
    assert!(std::ptr::eq(&*rc, &*rc_clone));

    let arc_clone = arc.clone();
    assert!(std::ptr::eq(&*arc, &*arc_clone));

    let r_clone = <&i32 as Clone>::clone(&r);
    assert!(std::ptr::eq(r, r_clone));

    // 4. StableDeref is implemented for interior mutability cell guards Ref and RefMut
    let cell = RefCell::new(55);
    {
        let borrowed = cell.borrow();
        assert_stable_deref(&borrowed);
        assert_eq!(*borrowed, 55);
    }
    {
        let mut borrowed_mut = cell.borrow_mut();
        assert_stable_deref(&borrowed_mut);
        *borrowed_mut = 77;
    }
    assert_eq!(*cell.borrow(), 77);

    // 5. Custom container types can implement StableDeref to preserve dereference target stability across moves
    let custom = CustomBox(Box::new(999));
    let addr_before = &*custom as *const i32;
    let moved_custom = custom;
    let addr_after = &*moved_custom as *const i32;
    assert_eq!(addr_before, addr_after);
    assert_stable_deref(&moved_custom);

    println!("All stable_deref_trait contract assertions passed successfully.");
}