Rust macro stringify

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August undefined, 2024

Webb17 apr. 2024 · stringify! () is a way to convert a bunch of tokens back to a string, but on a ‘best effort’ basis: It will convert the tokens back to text, and only insert spaces around … Webbmacro_rules! json { ($ ( $json :tt)+) => { ... }; } Construct a serde_json::Value from a JSON literal. let value = json!( { "code": 200, "success": true, "payload": { "features": [ "serde", "json" ] } }); Variables or expressions can be interpolated into the JSON literal.

rust - Interpolate `ident` in string literal in `macro_rules!` - Stack ...

WebbRust 对宏（macro）有着非常好的支持。宏能够使得你能够通过写代码的方式来生成代码，这通常被称为元编程（metaprogramming）。宏提供了类似函数的功能，但是没有运行时开销。但是，因为宏会在编译期进行展开（expand），所以它会有一些编译期的开销。 Rust 宏非常不同于 C 里面的宏。 Rust 宏会被应用于词法树（token tree），而 C 语言里 … Webb21 feb. 2015 · A macro which stringifies its argument. This macro will yield an expression of type &'static str which is the stringification of all the tokens passed to the macro. No restrictions are placed on the syntax of the macro invocation itself. Example fn main() { let one_plus_one = stringify!(1 + 1); assert_eq!(one_plus_one, "1 + 1"); } jb hi fi ms office

std::stringify! - Rust - Brandeis University

WebbThis macro takes any number of comma-separated literals, yielding an expression of type &'static str which represents all of the literals concatenated left-to-right. Integer and floating point literals are stringified in order to be concatenated. Examples let s = concat!("test", 10, 'b', true); assert_eq!(s, "test10btrue"); Run WebbLKML Archive on lore.kernel.org help / color / mirror / Atom feed * [PATCH v6 00/23] Rust support @ 2024-05-07 5:23 Miguel Ojeda 2024-05-07 5:23 ` [PATCH v6 01/23] kallsyms: avoid hardcoding the buffer size Miguel Ojeda ` (24 more replies) 0 siblings, 25 replies; 59+ messages in thread From: Miguel Ojeda @ 2024-05-07 5:23 UTC (permalink / raw) To: … loxley nutrition menu

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Webb首先， Rust Reference 的对应部分是这样描述这两个 specifier 的： tt 匹配一个 TokenTree （即一个 token 或成对括号 {} [] () 内的多个 token）。 expr 匹配一个表达式。 tt 匹配一个 / 一组 token，而 expr 匹配一个表达式，这是它们最直观的区别。例如： macro_rules! e_or_t { ($e:expr) => { "Expression" }; ($t:tt) => { "TokenTree" }; } fn main() { let e = e_or_t!(1); let t … WebbStringifies its arguments. This macro will yield an expression of type &'static str which is the stringification of all the tokens passed to the macro. No restrictions are placed on … jb hi fi navman specialsWebbmacro_rules! stringify { ($ ( $t: tt) *) => { ... }; } A macro which stringifies its arguments. This macro will yield an expression of type &'static str which is the stringification of all the … loxley lee woolridge senior

"Webb7 jan. 2024 · #1 I have an expansion like this in a macro: stringify!( $ns::$services ) It will generate something like: remote :: Add, but I would like it to be remote::Add, and I need it to be a &'static strso I'm not to fond on post processing it... " - Rust macro stringify

Rust macro stringify

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Webbassert_eq!( stringify!(unstringify!("example")), "example", ); Indeed, in the above code the macro stringify! is called before unstringify!, so what happens is stringify! simply … WebbAs mentioned in the methodical introduction, Rust has special expressions that can be used by macro transcribers to obtain information about metavariables that are otherwise difficult or even impossible to get. This chapter will introduce them more in-depth together with usage examples. $$. $ {count (ident, depth)} $ {index (depth)}

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Webb24 mars 2024 · Macros for all your token pasting needs The nightly-only concat_idents! macro in the Rust standard library is notoriously underpowered in that its concatenated identifiers can only refer to existing items, they can never be used to define something new. Webb21 mars 2024 · You can stringify just attributes: use stringify_attr::stringify_attr; assert_eq!( { #[stringify_attr(foo)] struct Foo; result!() }, "foo" ); Just items: use stringify_attr::stringify_item; assert_eq!( { #[stringify_item(foo)] struct Foo; result!() }, "struct Foo;" ); Or the whole thing:

Webb18 sep. 2024 · Rust std::stringify宏使用示例 mutourend 于 2024-09-18 15:56:54 发布 771 收藏 1 版权 macro_rules! stringify { ($ ($t:tt)*) => { ... }; } 1 2 3 作用是将其参数直接转换为字符串描述，类型为 &'static str 。适合用于描述数学公式变量名等。举例： let one_plus_one = stringify! (1 + 1); assert_eq! (one_plus_one, "1 + 1"); 1 2 3 参考资料： [1] … WebbArguments will be /// formatted according to the specified format string and the result will be passed to the writer. /// The writer may be any value with a `write_fmt` method; generally this comes from an /// implementation of either the [`fmt::Write`] or the [`io::Write`] trait. The macro /// returns whatever the `write_fmt` method returns ...

Webb16 dec. 2024 · I have tried using # [cfg (target_os = stringify! ($system))] but the cfg requires an actual string literal after target_os =, not just a compile-time string. rust rust … Webbproc_macro 包是 Rust 自带的，因此无需在 Cargo.toml 中引入依赖，它包含了相关的编译器 API ，可以用于读取和操作 Rust 源代码。由于我们为 hello_macro_derive 函数标记了 # [proc_macro_derive (HelloMacro)] ，当用户使用 # [derive (HelloMacro)] 标记了他的类型后， hello_macro_derive 函数就将被调用。这里的秘诀就是特征名 HelloMacro ，它就像一 …

Webb8 apr. 2024 · 1. Right, this only works if stringify! will be used in an expression context. It won't produce a string literal in e.g., # [cfg (feature = $feature_string_literal)], as it'll …

WebbRust by Example (RBE) is a collection of runnable examples that illustrate various Rust concepts and standard libraries. loxley north adelaideWebbConcatenates literals into a static string slice. This macro takes any number of comma-separated literals, yielding an expression of type &'static str which represents all of the … jb hi fi new moviesWebb31 okt. 2024 · This macro is mainly intended for debugging purposes and to improve the refactoring experience compared to stringify!(). Usage Add nameof as a dependency to your project's Cargo.toml file: [dependencies] nameof = "1.2.2" To use the macro (s), import the crate with the required annotation: loxley nursery sheffieldWebb10 apr. 2024 · rust - macro_rules! 过程宏学习笔记 macro_rules! rust中宏大致分两种: 过程宏: 形如 println!(), vec!() 这类; 属性宏: 形如 #[derive(Debug)] 这种, 写在struct头上的其中过程宏定义起来比较简单, 使用方便,简洁 loxley nursery schoolWebbA TT muncher is a recursive macro_rules! macro that works by incrementally processing its input one step at a time. At each step, it matches and removes (munches) some sequence of tokens from the start of its input, generates some intermediate output, then recurses on … jbhifi new releaseWebbThe stringify! macro used here is built into Rust. It takes a Rust expression, such as 1 + 2, and at compile time turns the expression into a string literal, such as "1 + 2". This is … jbhifi new phoneWebb19 okt. 2016 · In this trivial code sample the user wants to create a struct via macro expansion and write a unique comment for every different macro invokation. This means a unique comment for struct Foo and Bar which is currently not possible in the rust compiler when enabling: #! jb hifi music keyboard