ambiguous associated type when access Entity::Column about sea-orm

[tyt2y3]

This should not be a bug, because it's been this way since 0.1. As you already know, there are two workarounds:

1. do node::Column
2. do <Node as EntityTrait>::Column

But you've made an interesting observation, and the solution is right here! Nobody is using PrimaryKeyToColumn directly, as I imagine, so we can actually afford to break PrimaryKeyToColumn by renaming Column to something else. And now is probably the last time I'd change the Entity type system.

[tyt2y3]

PrimaryKeyToColumn by renaming Column to something else

Can you open a PR on this? I want to make this change

[Ayana-chan]

I apologize for my significant mistake. Renaming can't solve this problem. Actually, this problem would never be solved.

Look at this code:

trait T1 {
    type Name;
}

struct MyStruct {}

impl T1 for MyStruct {
    type Name = i32;
}

fn main() {
    let v: MyStruct::Name = 12;
}

Just one trait and just one associate type, but also get:

Compiling playground v0.0.1 (/playground)
error[E0223]: ambiguous associated type
  --> src/main.rs:13:12
   |
13 |     let v: MyStruct::Name = 12;
   |            ^^^^^^^^^^^^^^ help: use fully-qualified syntax: `<MyStruct as T1>::Name`

For more information about this error, try `rustc --explain E0223`.
error: could not compile `playground` (bin "playground") due to 1 previous error

It can be seen that the ambiguous associated type error is unrelated to associate types with duplicate names. It's easy to understand: If Rust allows to access associate type without fully-qualified syntax, any lib user who define an associate type with duplicate names would cause a break inside the lib.

As a conclusion, perhaps accessing associate types from outside of the trait must use fully-qualified syntax like <MyStruct as T1>::Name. So this issue dosen't point out any improvement points.

[tyt2y3]

There was a discussion around this before, but I couldn't seem to find it.

[tyt2y3]

Found it rust-lang/rust#8995