zerofrom 0.1.8

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

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

[[package]]
name = "zerofrom"
version = "0.1.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "0ec05a11813ea801ff6d75110ad09cd0824ddba17dfe17128ea0d5f68e6c5272"

[package]
name = "sample-zerofrom"
version = "1.0.0"
edition = "2021"
publish = false

[dependencies]
zerofrom = "=0.1.8"

[[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/zerofrom@0.1.8
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:cargo/zerofrom@0.1.8

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:sha256:7d8a1d9ebc0f065a6ae410d9e574a7bf91f9543edb0fa499096a7ec7fd4040ea","contract":["ZeroFrom constructs borrowed Cow from str and String without allocations","ZeroFrom converts String reference into str slice directly","ZeroFrom converts Option and tuple types preserving inner elements","ZeroFrom borrows slice references from slices and arrays","ZeroFrom constructs custom structs borrowing from existing data"],"goal":"verify pkg:cargo/zerofrom@0.1.8","kind":"HOW","packages":["pkg:cargo/zerofrom@0.1.8"],"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/zerofrom@0.1.8"],"schemaVersion":1,"subject":"pkg:cargo/zerofrom@0.1.8","verifierAdapter":"cargo@1"}

{
  "schemaVersion": 1,
  "goal": "verify pkg:cargo/zerofrom@0.1.8",
  "kind": "HOW",
  "packages": [
    "pkg:cargo/zerofrom@0.1.8"
  ]
}

//! Clean-room verification sample for zerofrom.

pub use zerofrom::*;

use std::borrow::Cow;
use zerofrom::ZeroFrom;

#[derive(Debug, PartialEq, Eq)]
struct MyData<'a> {
    field: Cow<'a, str>,
}

impl<'zf> ZeroFrom<'zf, str> for MyData<'zf> {
    fn zero_from(other: &'zf str) -> Self {
        MyData {
            field: ZeroFrom::zero_from(other),
        }
    }
}

impl<'zf> ZeroFrom<'zf, MyData<'_>> for MyData<'zf> {
    fn zero_from(other: &'zf MyData<'_>) -> Self {
        MyData {
            field: ZeroFrom::zero_from(&other.field),
        }
    }
}

fn main() {
    // 1. ZeroFrom constructs borrowed Cow from str and String without allocations
    let text = "sample text";
    let cow_from_str: Cow<str> = ZeroFrom::zero_from(text);
    assert!(matches!(cow_from_str, Cow::Borrowed(_)));
    assert_eq!(cow_from_str, "sample text");

    let owned_string = String::from("owned string");
    let cow_from_string: Cow<str> = ZeroFrom::zero_from(&owned_string);
    assert!(matches!(cow_from_string, Cow::Borrowed(_)));
    assert_eq!(cow_from_string, "owned string");

    // 2. ZeroFrom converts String reference into str slice directly
    let slice_from_string: &str = ZeroFrom::zero_from(&owned_string);
    assert_eq!(slice_from_string, "owned string");

    // 3. ZeroFrom converts Option and tuple types preserving inner elements
    let opt_string: Option<String> = Some(String::from("inner"));
    let opt_slice: Option<&str> = ZeroFrom::zero_from(&opt_string);
    assert_eq!(opt_slice, Some("inner"));

    let none_string: Option<String> = None;
    let none_slice: Option<&str> = ZeroFrom::zero_from(&none_string);
    assert_eq!(none_slice, None);

    let tuple_input = (123u32, String::from("tuple"));
    let tuple_borrowed: (u32, &str) = ZeroFrom::zero_from(&tuple_input);
    assert_eq!(tuple_borrowed, (123, "tuple"));

    // 4. ZeroFrom borrows slice references from slices and arrays
    let arr = [10u8, 20u8, 30u8];
    let slice_ref: &[u8] = ZeroFrom::zero_from(&arr[..]);
    assert_eq!(slice_ref, &[10, 20, 30]);

    let string_arr = [String::from("a"), String::from("b")];
    let slice_arr: [&str; 2] = ZeroFrom::zero_from(&string_arr);
    assert_eq!(slice_arr, ["a", "b"]);

    // 5. ZeroFrom constructs custom structs borrowing from existing data
    let custom = MyData::zero_from("custom data");
    assert_eq!(custom.field, "custom data");
    assert!(matches!(custom.field, Cow::Borrowed(_)));

    let reborrowed = MyData::zero_from(&custom);
    assert_eq!(reborrowed.field, "custom data");
    assert!(matches!(reborrowed.field, Cow::Borrowed(_)));

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