如何从可传递依赖项中销毁枚举

Question

src/main.rs:

fn main() {}
fn test(fetch: imap::types::Fetch) {
// Variable of type &BodyStructure
let bodystructure = fetch.bodystructure().unwrap();
match bodystructure {
imap_proto::BodyStructure::Basic { .. } => {}
imap_proto::BodyStructure::Message { .. } => {}
imap_proto::BodyStructure::Multipart { .. } => {}
imap_proto::BodyStructure::Text { .. } => {}
};
}

Cargo.toml:

[package]
name = "stackoverflow-68445809"
version = "0.1.0"
edition = "2018"
[dependencies]
imap = "2.4.1"
# This dependency solves the problem
# imap-proto = "0.10.2"

代码未编译：

error[E0433]: failed to resolve: use of undeclared crate or module `imap_proto`
--> src/main.rs:8:9
|
8 |         imap_proto::BodyStructure::Basic { .. } => {}
|         ^^^^^^^^^^ use of undeclared crate or module `imap_proto`
error[E0433]: failed to resolve: use of undeclared crate or module `imap_proto`
--> src/main.rs:9:9
|
9 |         imap_proto::BodyStructure::Message { .. } => {}
|         ^^^^^^^^^^ use of undeclared crate or module `imap_proto`
error[E0433]: failed to resolve: use of undeclared crate or module `imap_proto`
--> src/main.rs:10:9
|
10 |         imap_proto::BodyStructure::Multipart { .. } => {}
|         ^^^^^^^^^^ use of undeclared crate or module `imap_proto`
error[E0433]: failed to resolve: use of undeclared crate or module `imap_proto`
--> src/main.rs:11:9
|
11 |         imap_proto::BodyStructure::Text { .. } => {}
|         ^^^^^^^^^^ use of undeclared crate or module `imap_proto`

imap-proto是imap机箱的依赖项，代码在将依赖项imap-proto = "0.10.2"添加到我的项目后编译。

有没有一种方法可以在不显式依赖于imap-proto机箱的情况下销毁变量bodystructure？只为destructure变量添加额外依赖项的要求对我来说似乎很奇怪。我做错了什么吗？

Answer 1

根据我对imap机箱文档的阅读，bodystructure函数返回一个Option<amp；车身结构<'a>gt；，其中BodyStructure是在imap原型机箱中定义的枚举。所以我认为答案是否定的，除了imap之外，你还必须将imap-proto作为一个依赖项。

来源：https://docs.rs/imap/2.4.1/imap/types/struct.Fetch.html#method.bodystructure