stable_deref_trait 1.2.1: stable_deref_trait

# 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"

# stable_deref_trait 1.2.1 Stable and Clone-Stable Dereference Contracts

## What `search_known_solution` answered
`search_known_solution` returned NO_SAFE_MATCH for stable_deref_trait@1.2.1. This sample verifies the core address stability contracts for StableDeref and CloneStableDeref across standard library and custom types.

## What a model would have written instead
A model might attempt to implement CloneStableDeref for Box or Vec, or implement StableDeref on inline structs without heap indirection, violating address stability when moved.

## How the wrong version fails
Implementing CloneStableDeref on Box or Vec is invalid because cloning allocates a new heap buffer at a different address. Implementing StableDeref on an inline struct invalidates pointers when the struct is moved in memory.

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 stable_deref_trait in 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
Demonstrate these symbols/APIs:
  - stable_deref_trait

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:sha256:8decc3f9b1faf9114b084692e0a5f1ad52b78b72513dd2eb09b8937d4df9bb91","contract":["Box, Vec, String, Rc, and Arc implement StableDeref guaranteeing address stability across moves","Rc and Arc implement CloneStableDeref guaranteeing clones dereference to the identical memory address","Shared reference \u0026T and Ref\u003cT\u003e implement StableDeref","Mutable reference \u0026mut T implements StableDeref","Custom types wrapping heap containers can safely implement StableDeref to guarantee stable dereference addresses"],"goal":"verify stable_deref_trait in pkg:cargo/stable_deref_trait@1.2.1","kind":"HOW","packages":["pkg:cargo/stable_deref_trait@1.2.1"],"schemaVersion":1,"symbols":["stable_deref_trait"]},"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","symbols":["stable_deref_trait"],"verifierAdapter":"cargo@1"}

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

//! Clean-room verification sample for stable_deref_trait.

pub use stable_deref_trait::*;

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

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

struct CustomHolder<T>(Box<T>);

impl<T> std::ops::Deref for CustomHolder<T> {
    type Target = T;
    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

unsafe impl<T> StableDeref for CustomHolder<T> {}

fn main() {
    // 1. Box, Vec, String, Rc, and Arc implement StableDeref guaranteeing address stability across moves
    let b = Box::new(12345u32);
    let ptr_before = &*b as *const u32;
    assert_stable_deref(&b);
    let moved_b = b;
    let ptr_after = &*moved_b as *const u32;
    assert_eq!(ptr_before, ptr_after);
    assert_eq!(*moved_b, 12345);

    let v = vec![10u8, 20, 30];
    let v_ptr_before = v.as_ptr();
    assert_stable_deref(&v);
    let moved_v = v;
    let v_ptr_after = moved_v.as_ptr();
    assert_eq!(v_ptr_before, v_ptr_after);

    let s = String::from("stable deref string");
    let s_ptr_before = s.as_ptr();
    assert_stable_deref(&s);
    let moved_s = s;
    let s_ptr_after = moved_s.as_ptr();
    assert_eq!(s_ptr_before, s_ptr_after);

    let rc = Rc::new(999i64);
    let rc_ptr_before = &*rc as *const i64;
    assert_stable_deref(&rc);
    let moved_rc = rc;
    let rc_ptr_after = &*moved_rc as *const i64;
    assert_eq!(rc_ptr_before, rc_ptr_after);

    let arc = Arc::new(888i64);
    let arc_ptr_before = &*arc as *const i64;
    assert_stable_deref(&arc);
    let moved_arc = arc;
    let arc_ptr_after = &*moved_arc as *const i64;
    assert_eq!(arc_ptr_before, arc_ptr_after);

    // 2. Rc and Arc implement CloneStableDeref guaranteeing clones dereference to the identical memory address
    let rc_orig = Rc::new(42u32);
    assert_clone_stable_deref(&rc_orig);
    let rc_clone = Rc::clone(&rc_orig);
    assert_eq!(&*rc_orig as *const u32, &*rc_clone as *const u32);

    let arc_orig = Arc::new(100u64);
    assert_clone_stable_deref(&arc_orig);
    let arc_clone = Arc::clone(&arc_orig);
    assert_eq!(&*arc_orig as *const u64, &*arc_clone as *const u64);

    // 3. Shared reference &T and Ref<T> implement StableDeref
    let val: i32 = 77;
    let r: &i32 = &val;
    assert_stable_deref(&r);
    assert_clone_stable_deref(&r);
    let r_clone = r;
    assert_eq!(&*r as *const i32, &*r_clone as *const i32);

    let cell = RefCell::new(55i32);
    let cell_ref = cell.borrow();
    assert_stable_deref(&cell_ref);
    assert_eq!(*cell_ref, 55);

    // 4. Mutable reference &mut T implements StableDeref
    let mut mut_val: i32 = 88;
    let mut_ref: &mut i32 = &mut mut_val;
    assert_stable_deref(&mut_ref);
    assert_eq!(*mut_ref, 88);

    // 5. Custom types wrapping heap containers can safely implement StableDeref to guarantee stable dereference addresses
    let holder = CustomHolder(Box::new("custom stable"));
    let holder_ptr_before = &*holder as *const &str;
    assert_stable_deref(&holder);
    let moved_holder = holder;
    let holder_ptr_after = &*moved_holder as *const &str;
    assert_eq!(holder_ptr_before, holder_ptr_after);
    assert_eq!(*moved_holder, "custom stable");

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