CodeSampleX

Sample

displaydoc 0.2.7

Verified sample for cargo displaydoc 0.2.7. The contract ran on rust 1 · linux alpine/x64 · docker and passed: Display derive formats enum unit variants…

sha256:670cd104b41a254b8472dc5f93fbb47342b9984724707847dbf13332cb1c8af9

This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured. How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people. MIT-0

Execution evidence

The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.

Evidence basis
Signed contract pass
Verification receipts
1
Signing keys that built it
1
Declared environment linux · alpine · musl x64 cargo

Verification-run environments

Environment Contract Stages Run
rust 1 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · cargo@1rust:1-alpine@sha256:a10e64dd139b…
2026-09-19

Case

HOW
Goal
verify pkg:cargo/displaydoc@0.2.7
Packages
Created
2026-09-18T13:09:28Z

Contract

  1. Display derive formats enum unit variants using doc comments
  2. Display derive formats positional tuple fields using {0} and {1:?}
  3. Display derive formats named struct variant fields using {field}
  4. Display derive formats structs and tuple structs using doc comments
  5. prefix_enum_doc_attributes combines enum doc comment with variant doc comments
  6. displaydoc attribute overrides doc comment on struct or enum variant
  7. Display derive works with generic structs without explicit Display bounds on definition

Files

  • Cargo.lock
  • Cargo.toml
  • PROMPT.md
  • csx.json
  • spec.json
  • src/lib.rs
  • test/contract.rs

Download the source artifact (tar.gz)

Source

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

[[package]]
name = "displaydoc"
version = "0.2.7"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c6232dd377dcc64799954cbd3a9bb882e9cdc1308ccd87b1c098f1fb2eaf82a8"
dependencies = [
 "proc-macro2",
 "quote",
 "syn",
]

[[package]]
name = "proc-macro2"
version = "1.0.107"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "985e7ec9bb745e6ce6535b544d84d6cd6f7ad8bd711c398938ae983b91a766d9"
dependencies = [
 "unicode-ident",
]

[[package]]
name = "quote"
version = "1.0.47"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "1fbf4db142a473a8d80c26bbf18454ed458bf8d26c8219c331daecfdbd079001"
dependencies = [
 "proc-macro2",
]

[[package]]
name = "sample-displaydoc"
version = "1.0.0"
dependencies = [
 "displaydoc",
]

[[package]]
name = "syn"
version = "3.0.6"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "8593e8e72159ed2257d083c7a454a85cbf854f37a0966d8d483aff8c8a3ebcee"
dependencies = [
 "proc-macro2",
 "quote",
 "unicode-ident",
]

[[package]]
name = "unicode-ident"
version = "1.0.26"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d245f478577f809a851594d02313b640fb437e0bb33866753cff937863096954"
Cargo.toml
[package]
name = "sample-displaydoc"
version = "1.0.0"
edition = "2021"
publish = false

[dependencies]
displaydoc = "=0.2.7"

[[bin]]
name = "contract"
path = "test/contract.rs"
PROMPT.md
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/displaydoc@0.2.7
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:cargo/displaydoc@0.2.7

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.
csx.json
{"case":{"caseId":"case:sha256:5f426b9815b5e9f4e50118edf2983557414f0601cdb030d94ef7657997178c29","contract":["Display derive formats enum unit variants using doc comments","Display derive formats positional tuple fields using {0} and {1:?}","Display derive formats named struct variant fields using {field}","Display derive formats structs and tuple structs using doc comments","prefix_enum_doc_attributes combines enum doc comment with variant doc comments","displaydoc attribute overrides doc comment on struct or enum variant","Display derive works with generic structs without explicit Display bounds on definition"],"goal":"verify pkg:cargo/displaydoc@0.2.7","kind":"HOW","packages":["pkg:cargo/displaydoc@0.2.7"],"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/displaydoc@0.2.7"],"schemaVersion":1,"subject":"pkg:cargo/displaydoc@0.2.7","verifierAdapter":"cargo@1"}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify pkg:cargo/displaydoc@0.2.7",
  "kind": "HOW",
  "packages": [
    "pkg:cargo/displaydoc@0.2.7"
  ]
}
src/lib.rs
//! Clean-room verification sample for displaydoc.

pub use displaydoc::*;
test/contract.rs
use displaydoc::Display;

/// Simple error enum for testing
#[derive(Display, Debug, PartialEq)]
pub enum SimpleError {
    /// An unknown error occurred
    Unknown,
    /// Failed with code: {0} (details: {1:?})
    WithCode(u32, &'static str),
    /// Key {key} not found in scope {scope}
    MissingKey { key: String, scope: &'static str },
}

/// Service error
#[derive(Display, Debug, PartialEq)]
#[prefix_enum_doc_attributes]
pub enum ServiceError {
    /// connection timed out
    Timeout,
    /// unauthorized access: {0}
    Unauthorized(&'static str),
}

/// Point at ({x}, {y})
#[derive(Display, Debug, PartialEq)]
pub struct Point {
    pub x: i32,
    pub y: i32,
}

/// Container holding {0}
#[derive(Display, Debug, PartialEq)]
pub struct Container(pub &'static str);

/// Wrapped value: {0}
#[derive(Display, Debug, PartialEq)]
pub struct Wrapper<T>(pub T);

/// Original doc comment that gets overridden
#[derive(Display, Debug, PartialEq)]
#[displaydoc("Overridden display message: {code}")]
pub struct Overridden {
    pub code: u32,
}

fn main() {
    // 1. Display derive formats enum unit variants using doc comments
    let err_unknown = SimpleError::Unknown;
    assert_eq!(format!("{}", err_unknown), "An unknown error occurred");

    // 2. Display derive formats positional tuple fields using {0} and {1:?}
    let err_code = SimpleError::WithCode(404, "not found");
    assert_eq!(format!("{}", err_code), "Failed with code: 404 (details: \"not found\")");

    // 3. Display derive formats named struct variant fields using {field}
    let err_missing = SimpleError::MissingKey {
        key: "api_key".to_string(),
        scope: "auth",
    };
    assert_eq!(
        format!("{}", err_missing),
        "Key api_key not found in scope auth"
    );

    // 4. Display derive formats structs and tuple structs using doc comments
    let point = Point { x: 10, y: 20 };
    assert_eq!(format!("{}", point), "Point at (10, 20)");
    let container = Container("item");
    assert_eq!(format!("{}", container), "Container holding item");

    // 5. prefix_enum_doc_attributes combines enum doc comment with variant doc comments
    let svc_timeout = ServiceError::Timeout;
    assert_eq!(format!("{}", svc_timeout), "Service error: connection timed out");
    let svc_unauth = ServiceError::Unauthorized("admin");
    assert_eq!(format!("{}", svc_unauth), "Service error: unauthorized access: admin");

    // 6. displaydoc attribute overrides doc comment on struct or enum variant
    let overridden = Overridden { code: 500 };
    assert_eq!(format!("{}", overridden), "Overridden display message: 500");

    // 7. Display derive works with generic structs without explicit Display bounds on definition
    let wrapper_str = Wrapper("hello world");
    assert_eq!(format!("{}", wrapper_str), "Wrapped value: hello world");
    let wrapper_int = Wrapper(12345);
    assert_eq!(format!("{}", wrapper_int), "Wrapped value: 12345");

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

Origin Seeder

anonymous