Sample

Deserializing JSON strings into borrowed &'a str fails at runtime on any escape sequence, requiring Cow<'a, str> with #[serde(borrow)] to achieve zero-copy deserialization that safely falls back to allocation for escaped characters

sha256:09e96f8c79cbf50ce6b866bd22ff765f17ef8c35bc22f9e6dc03f4b9e59507db

Case

Goal

Deserializing JSON strings into borrowed &'a str fails at runtime on any escape sequence, requiring Cow<'a, str> with #[serde(borrow)] to achieve zero-copy deserialization that safely falls back to allocation for escaped characters HOW

Packages

serde 1.0.229 serde_json 1.0.151

Environment

rust

Created

2026-08-16T06:28:08Z

Contract

• assert serde_json from_str borrows unescaped JSON string fields directly into &'a str with zero allocation
• assert serde_json from_str rejects &'a str deserialization on escape sequences like \n, \", \t, and \uXXXX with invalid type error
• assert serde_json from_str with #[serde(borrow)] Cow<'a, str> borrows unescaped strings as Cow::Borrowed and decodes escaped strings into Cow::Owned
• assert serde_json from_str with unannotated Cow<'a, str> defaults to DeserializeOwned and unconditionally allocates Cow::Owned
• assert serde_json from_slice matches from_str zero-copy borrowing behavior for &'a str and Cow<'a, str>

Files

• .gitignore
• Cargo.lock
• Cargo.toml
• NOTES.md
• csx.json
• src/lib.rs

Download the verified artifact (tar.gz) — the exact bytes the contract ran against

Origin Seeder

csx-seed

Verification receipts

• rust 1 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · cargo@1 · 2026-08-16 · ed25519:d91480838ac982c9