{"id":57142,"library":"cfg-if","title":"cfg-if","description":"A macro to ergonomically define an item depending on a large number of #[cfg] parameters, structured like an if-else chain.","status":"active","version":"1.0.4","language":"rust","source_language":null,"source_url":"https://github.com/rust-lang/cfg-if","tags":["macro","conditional-compilation","cfg"],"install":[{"cmd":"# Cargo.toml\n[dependencies]\ncfg-if = \"1.0.4\"","lang":"toml","label":"Cargo.toml"},{"cmd":"cargo add cfg-if","lang":"bash","label":"cargo add"}],"dependencies":[],"imports":[{"symbol":"cfg_if","correct":"use cfg_if::cfg_if;"}],"quickstart":{"code":"use cfg_if::cfg_if;\n\ncfg_if! {\n    if #[cfg(unix)] {\n        fn platform() -> &'static str { \"unix\" }\n    } else if #[cfg(windows)] {\n        fn platform() -> &'static str { \"windows\" }\n    } else {\n        fn platform() -> &'static str { \"unknown\" }\n    }\n}\n\nfn main() {\n    println!(\"{}\", platform());\n}","lang":"rust","description":"Shows how to use cfg_if! to conditionally compile code based on platform."},"warnings":[],"env_vars":null,"search_vec":"'cfg':2,17,30 'cfg-if':1 'chain':25 'compil':29 'condit':28 'conditional-compil':27 'defin':8 'depend':11 'els':24 'ergonom':7 'if-els':22 'item':10 'larg':14 'like':20 'macro':5,26 'number':15 'paramet':18 'structur':19","created_at":"2026-06-16T15:30:05.790760+00:00","updated_at":"2026-06-16T15:30:05.790760+00:00","problems":[],"ecosystem":"crates","meta_description":null,"install_score":null,"quickstart_score":null,"quickstart_tag":null,"pypi_latest":null,"cli_name":null,"cli_version":null,"type":"library","homepage":"https://github.com/rust-lang/cfg-if","github":"https://github.com/rust-lang/cfg-if","docs":"https://docs.rs/cfg-if/","changelog":null,"pypi":null,"npm":null,"openapi_spec":null,"status_page":null,"smithery":null,"categories":["utility"],"base_url":null,"auth_type":null,"provenance":{"verified_status":null,"verified_at":null,"last_verified":"2026-06-16","next_check":"2026-12-13","install_tag":null}}