Sub-modules - rust-course

Inside a module:

mod foo {
  struct Foo {
    a: i16
  }
}

let x = foo::Foo {a: 12};
x.a

[E0603] Error: struct `Foo` is private
   ╭─[ command_2:1:1 ]
   │
 7 │ let x = foo::Foo {a: 12};
   │              ─┬─  
   │               ╰─── private struct
   │
   ├─[ command_2:1:1 ]
   │
 2 │   struct Foo {
   │   ─────┬────  
   │        ╰────── note: the struct `Foo` is defined here
───╯

[E0616] Error: field `a` of struct `Foo` is private
   ╭─[ command_2:1:1 ]
   │
 8 │ x.a
   │   ┬  
   │   ╰── private field
───╯

mod foo {
  pub struct Foo {
    a: i16
  }
}

let x = foo::Foo {a: 12};
x.a

[E0616] Error: field `a` of struct `Foo` is private
   ╭─[ command_3:1:1 ]
   │
 8 │ x.a
   │   ┬  
   │   ╰── private field
───╯

mod foo {
  pub struct Foo {
    pub a: i16
  }
}

let x = foo::Foo {a: 12};
x.a

12

Using constructor function new():

mod foo {
  pub struct Foo {
    a: i16
  }

  impl Foo {

    pub fn new(value: i16) -> Self {
      Self { a: value }
    }

    pub fn a(&self) -> i16 {
      self.a
    }
  }
}

let x = foo::Foo::new(12);
x.a()

The type of the variable x was redefined, so was lost.

12

43.2 Sub-modules