macros - 如何在宏中包含唯一匹配案例的文档？

Question

可以为导出宏的各个匹配案例编写文档。

/// This macro does stuff // this works
#[macro_export]
macro_rules! macro{
    /// Today it's time for cats // error: no rules expected the token `[`
    (cat) => { ... };
    /// Today it's time for dogs // error: no rules expected the token `[`
    (dog) => { ... };
    /// Why not both // error: no rules expected the token `[`
    (cats and dogs) => { ... };
}

这样的事情是可能的还是我必须这样做:

/// This macro does stuff
/// `(cat)` - Today it's time for cats
/// `(dog)` - Today it's time for dogs
/// `(cats and dogs)` - Why not both
#[macro_export]
macro_rules! macro{
    (cat) => { ... }; 
    (dog) => { ... };
    (cats and dogs) => { ... };
}

Answer 1

你不能。唯一可以将文档附加到宏的地方是作为一个整体的宏。