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This post is auto-generated from RSS feed The Rust Programming Language Forum - Latest topics. Source: Pub type exported or not

While working on a Rust library, I encountered this thing I didn't realize before:

A pub type Foo can be accessed by external code even when Foo was not exported in lib.rs.

For example, lib.rs has exported a public function like:

pub fn my_fn() -> Foo

The external user can call my_fn() to get a Foo and even call Foo.foo_func as long as foo_func is pub.

It means the external code can use Foo for quite a bit use cases by Rust's type inference. But this creates an interesting scenario: in cargo doc output, the user can see this my_fn returns a Foo, but they cannot get the doc of Foo as it's not exported.

A random example: ArgMatches in clap - Rust

There is no doc for the public type Occurrences.

I guess basically Rust does not force an external public type to be exported in a lib. (Or, should I call such type half-pub type?) But I'm curious if that is a design choice or by accident?

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