如何在Rust中获取 struct 字段名

发布于05月11日

Rust's struct是否有JS's Object.keys()的等效物？

我需要一些东西来从 struct 字段名生成CSV标题(我使用rust-csv).

struct Export {
    first_name: String,
    last_name: String,
    gender: String,
    date_of_birth: String,
    address: String
}

//... some code

let mut wrtr = Writer::from_file("/home/me/export.csv").unwrap().delimiter(b'\t');

wrtr.encode(/* WHAT TO WRITE HERE TO GET STRUCT NAMES as tuple of strings or somethings */).is_ok()

推荐答案

Rust中当前元编程的主要方法是via macros.在这种情况下，您可以捕获所有字段名，然后添加一个方法，返回它们的字符串形式:

macro_rules! zoom_and_enhance {
    (struct $name:ident { $($fname:ident : $ftype:ty),* }) => {
        struct $name {
            $($fname : $ftype),*
        }

        impl $name {
            fn field_names() -> &'static [&'static str] {
                static NAMES: &'static [&'static str] = &[$(stringify!($fname)),*];
                NAMES
            }
        }
    }
}

zoom_and_enhance!{
struct Export {
    first_name: String,
    last_name: String,
    gender: String,
    date_of_birth: String,
    address: String
}
}

fn main() {
    println!("{:?}", Export::field_names());
}

对于高级宏，请务必查看The Little Book of Rust Macros.