Why do I have access to a private member?

[bbasics]

Here is my minimal code:

use bevy::prelude::*;
use bevy_mod_picking::prelude::*;

fn main() {
    let mut app = App::new();
    app.add_plugins(DefaultPlugins);
    app.add_systems(Startup, setup);
    app.add_plugins(DefaultPickingPlugins);
    app.run();
}

#[derive(Component)]
struct Cube {
    // The private member
    click_counter: u32,
}

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    // Cube
    commands.spawn((
        PbrBundle {
            mesh: meshes.add(Cuboid::new(1.0, 1.0, 1.0)),
            material: materials.add(Color::srgb_u8(124, 144, 255)),
            transform: Transform::from_xyz(0.0, 0.5, 0.0),
            ..default()
        },
        Cube { click_counter: 0 },
        On::<Pointer<Click>>::target_component_mut::<Cube>(|event, cube| {
            // Why do I have access to a private member here?
            cube.click_counter += 1;
            println!("Clicked on {:?} times {}", event.target(), cube.click_counter);
        }),
    ));
    // Light
    commands.spawn(PointLightBundle {
        point_light: PointLight {
            shadows_enabled: true,
            ..default()
        },
        transform: Transform::from_xyz(4.0, 8.0, 4.0),
        ..default()
    });
    // Camera
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(-2.5, 4.5, 9.0).looking_at(Vec3::ZERO, Vec3::Y),
        ..default()
    });
}

I should not have access to this member as it is private. I don't know if it is due to the bevy_mod_picking plugin or bevy Component.

[mockersf]

from https://doc.rust-lang.org/reference/visibility-and-privacy.html

If an item is private, it may be accessed by the current module and its descendants.

private is not private to the current module, you should put it in another if you want it to fail compilation

[bugsweeper]

you should put it in another if you want it to fail compilation

Literally speaking, if you replace

#[derive(Component)]
struct Cube {
    // The private member
    click_counter: u32,
}

with

mod Private {
    use bevy::prelude::*;
    #[derive(Component)]
    pub struct Cube {
        // The private member
        click_counter: u32,
    }
}
use Private::Cube;

you would get errors like:

error[E0616]: field `click_counter` of struct `Private::Cube` is private
  --> src/main.rs:38:18
   |
38 |             cube.click_counter += 1;
   |                  ^^^^^^^^^^^^^ private field

error[E0616]: field `click_counter` of struct `Private::Cube` is private
  --> src/main.rs:42:22
   |
42 |                 cube.click_counter
   |                      ^^^^^^^^^^^^^ private field

[bbasics]

I just lean something on rust, didn't know the visibility was at the module level. thank you !