================================================================================
Modules
================================================================================

mod english;

mod english {}

mod english {
    mod greetings {}
    mod farewells {}
}

pub mod english;

--------------------------------------------------------------------------------

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        (declaration_list))
      (mod_item
        (identifier)
        (declaration_list))))
  (mod_item
    (visibility_modifier)
    (identifier)))

================================================================================
Extern crate declarations
================================================================================

extern crate std;
extern crate std as ruststd;
pub extern crate futures;

--------------------------------------------------------------------------------

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    (identifier))
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    (visibility_modifier)
    (crate)
    (identifier)))

================================================================================
Function declarations
================================================================================

fn main() {}

fn add(x: i32, y: i32) -> i32 {
    return x + y;
}

fn takes_slice(slice: &str) {
    println!("Got: {}", slice);
}

fn foo() -> [u32; 2] {
    return [1, 2];
}

fn foo() -> (u32, u16) {
    return (1, 2);
}

fn foo() {
    return
}

fn foo(x: impl FnOnce() -> result::Result<T, E>) {}

fn foo(#[attr] x: i32, #[attr] x: i64) {}

fn accumulate(self) -> Machine<{State::Accumulate}> {}

fn foo(bar: impl for<'a> Baz<Quux<'a>>) {}

--------------------------------------------------------------------------------

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            (identifier))))))
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            (integer_literal))))))
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              type_arguments: (type_arguments
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    body: (block))
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          (identifier)))
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        type: (primitive_type)))
    body: (block))
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    parameters: (parameters
      (self_parameter
        (self)))
    return_type: (generic_type
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            path: (identifier)
            name: (identifier)))))
    body: (block))
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              (generic_type
                type: (type_identifier)
                type_arguments: (type_arguments
                  (lifetime
                    (identifier)))))))))
    body: (block)))

================================================================================
Const function declarations
================================================================================

const fn main() {}

--------------------------------------------------------------------------------

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    (parameters)
    (block)))

================================================================================
Functions with abstract return types
================================================================================

fn triples(a: impl B) -> impl Iterator<Item=(usize)> {
}

--------------------------------------------------------------------------------

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        (type_arguments
          (type_binding
            (type_identifier)
            (tuple_type
              (primitive_type))))))
    (block)))

================================================================================
Diverging functions
================================================================================

fn aborts() -> ! {
}

--------------------------------------------------------------------------------

(source_file
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    (identifier)
    (parameters)
    (empty_type)
    (block)))

================================================================================
Extern function declarations
================================================================================

extern "C" fn foo() {}
extern "C" fn printf(
    *const c_char,
    ...,
) {}

--------------------------------------------------------------------------------

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        (string_literal)))
    (identifier)
    (parameters
      (pointer_type
        (type_identifier))
      (variadic_parameter))
    (block)))

================================================================================
Use declarations
================================================================================

use abc;
use phrases::japanese;
use sayings::english::greetings;
use sayings::english::greetings as en_greetings ;
use phrases::english::{greetings,farewells};
use sayings::japanese::farewells::*;
pub use self::greetings::hello;
use sayings::english::{self, greetings as en_greetings, farewells as en_farewells};
use three::{ dot::{one, four} };
use my::{ some::* };
use my::{*};

--------------------------------------------------------------------------------

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      name: (identifier)))
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          name: (identifier))
        name: (identifier))
      alias: (identifier)))
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          path: (identifier)
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        name: (identifier))))
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      name: (identifier)))
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          alias: (identifier)))))
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          path: (identifier)
          list: (use_list
            (identifier)
            (identifier))))))
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        (use_wildcard
          (identifier)))))
  (use_declaration
    argument: (scoped_use_list
      path: (identifier)
      list: (use_list
        (use_wildcard)))))

================================================================================
Variable bindings
================================================================================

let x;
let x = 42;
let x: i32;
let x: i8 = 42;
let mut x = 5;
let y: bool = false;
let bool: bool = false;
let u32: str = "";

--------------------------------------------------------------------------------

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    (identifier))
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    (identifier)
    (primitive_type)
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  (let_declaration
    (identifier)
    (primitive_type)
    (boolean_literal))
  (let_declaration
    (identifier)
    (primitive_type)
    (string_literal)))

================================================================================
Let-else Statements
================================================================================

let Foo::Bar {
    texts,
    values,
} = foo().bar().await? else {
    return Err(index)
};

let Some(x) = y else {
    let None = z else {
        foo();
        break;
    };
    continue;
};

--------------------------------------------------------------------------------

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    value: (try_expression
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              function: (identifier)
              arguments: (arguments))
            field: (field_identifier))
          arguments: (arguments))))
    alternative: (block
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          arguments: (arguments
            (identifier))))))
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    value: (identifier)
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        value: (identifier)
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          (expression_statement
            (call_expression
              function: (identifier)
              arguments: (arguments)))
          (expression_statement
            (break_expression))))
      (expression_statement
        (continue_expression)))))

================================================================================
Let declarations with if expressions as the value
================================================================================

let a = if b {
    c
} else {
    d
};

--------------------------------------------------------------------------------

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    (identifier)
    (if_expression
      (identifier)
      (block
        (identifier))
      (else_clause
        (block
          (identifier))))))

================================================================================
Let declarations with contextual keywords as names
================================================================================

let default = 1;
let union = 2;

--------------------------------------------------------------------------------

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  (let_declaration
    (identifier)
    (integer_literal)))

================================================================================
Structs
================================================================================

struct Proton;
struct Electron {}
struct Person {pub name: String, pub age: u32}
struct Point {
  x: i32,

  #[attribute1]
  y: i32,
}
struct Color(pub i32, i32, i32);
struct Inches(i32);

--------------------------------------------------------------------------------

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      (primitive_type)
      (primitive_type)))
  (struct_item
    (type_identifier)
    (ordered_field_declaration_list
      (primitive_type))))

================================================================================
Unions
================================================================================

pub union in6_addr__bindgen_ty_1 {
    pub __u6_addr8: [__uint8_t; 16usize],
    pub __u6_addr16: [__uint16_t; 8usize],
    pub __u6_addr32: [__uint32_t; 4usize],
    _bindgen_union_align: [u32; 4usize],
}

--------------------------------------------------------------------------------

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          (type_identifier)
          (integer_literal)))
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        (field_identifier)
        (array_type
          (type_identifier)
          (integer_literal)))
      (field_declaration
        (field_identifier)
        (array_type
          (primitive_type)
          (integer_literal))))))

================================================================================
Generic structs
================================================================================

struct A<B> {}
struct C<'a, 'b> {}
struct C<'a,> {}
struct D<const SIZE: usize> {}

--------------------------------------------------------------------------------

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      (lifetime
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    body: (field_declaration_list))
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    type_parameters: (type_parameters
      (const_parameter
        name: (identifier)
        type: (primitive_type)))
    body: (field_declaration_list)))

================================================================================
Enums
================================================================================

pub enum Option<T> {
    None,
    Some(T),
}

pub enum Node<T: Item> {
    Internal {
        children: Vec<Tree<T>>,
        height: u16
    },
    #[attribute1]
    #[attribute2]
    Leaf {
        value: T
    }
}

--------------------------------------------------------------------------------

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          (type_identifier)))))
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          (type_identifier))))
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                    (type_identifier))))))
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            (field_identifier)
            (primitive_type))))
      (attribute_item
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          (identifier)))
      (attribute_item
        (attribute
          (identifier)))
      (enum_variant
        (identifier)
        (field_declaration_list
          (field_declaration
            (field_identifier)
            (type_identifier)))))))

================================================================================
Enums with values specified
================================================================================

pub enum c_style_enum {
    val1 = 1,
    val2 = 2
}

--------------------------------------------------------------------------------

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      (enum_variant
        (identifier)
        (integer_literal)))))

================================================================================
Generic functions
================================================================================

pub fn splice<T: Into<Text>>(&mut self, old_range: Range<usize>, new_text: T) {
}
pub fn uninit_array<const LEN: usize>() -> [Self; LEN] {}

--------------------------------------------------------------------------------

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            type: (type_identifier)
            type_arguments: (type_arguments
              (type_identifier))))))
    parameters: (parameters
      (self_parameter
        (mutable_specifier)
        (self))
      (parameter
        pattern: (identifier)
        type: (generic_type
          type: (type_identifier)
          type_arguments: (type_arguments
            (primitive_type))))
      (parameter
        pattern: (identifier)
        type: (type_identifier)))
    body: (block))
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    type_parameters: (type_parameters
      (const_parameter
        name: (identifier)
        type: (primitive_type)))
    parameters: (parameters)
    return_type: (array_type
      element: (type_identifier)
      length: (identifier))
    body: (block)))

================================================================================
Functions with mutable parameters
================================================================================

fn foo(mut x : u32) {
}

--------------------------------------------------------------------------------

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    (identifier)
    (parameters
      (parameter
        (mutable_specifier)
        (identifier)
        (primitive_type)))
    (block)))

================================================================================
Functions with destructured parameters
================================================================================

fn f1([x, y]: [u32; 2]) {}
fn f2(&x: &Y) {}
fn f3((x, y): (T, U)) {}

--------------------------------------------------------------------------------

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    (identifier)
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          (identifier))
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    (block))
  (function_item
    (identifier)
    (parameters
      (parameter
        (reference_pattern
          (identifier))
        (reference_type
          (type_identifier))))
    (block))
  (function_item
    (identifier)
    (parameters
      (parameter
        (tuple_pattern
          (identifier)
          (identifier))
        (tuple_type
          (type_identifier)
          (type_identifier))))
    (block)))

================================================================================
Functions with custom types for self
================================================================================

trait Callback {
    fn call(self: Box<Self>);
}

--------------------------------------------------------------------------------

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    (type_identifier)
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        (identifier)
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            (self)
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              (type_identifier)
              (type_arguments
                (type_identifier)))))))))

================================================================================
Constant items
================================================================================

const N: i32 = 5;

trait Foo {
    const X: u8;
}

--------------------------------------------------------------------------------

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    (identifier)
    (primitive_type)
    (integer_literal))
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    (type_identifier)
    (declaration_list
      (const_item
        (identifier)
        (primitive_type)))))

================================================================================
Static items
================================================================================

static N: i32 = 5;
static mut __progname: *mut ::c_char;

--------------------------------------------------------------------------------

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    (identifier)
    (primitive_type)
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  (static_item
    (mutable_specifier)
    (identifier)
    (pointer_type
      (mutable_specifier)
      (scoped_type_identifier
        (type_identifier)))))

================================================================================
Static 'ref' items using lazy_static
================================================================================

static ref ONE: usize = 0;

--------------------------------------------------------------------------------

(source_file
  (static_item
    (identifier)
    (primitive_type)
    (integer_literal)))

================================================================================
Type aliases
================================================================================

type Inch = u64;
type Name<T> = Vec<T>;

--------------------------------------------------------------------------------

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      (type_identifier)
      (type_arguments
        (type_identifier)))))

================================================================================
Empty statements
================================================================================

fn main() {
    ;
}

--------------------------------------------------------------------------------

(source_file
  (function_item
    (identifier)
    (parameters)
    (block
      (empty_statement))))

================================================================================
Attributes
================================================================================

#[test]
fn test_foo() {}

#[derive(Debug)]
struct Baz;

#[derive(Debug, Eq,)]
struct Foo;

#[cfg(target_os = "macos")]
mod macos_only {}

#![allow(clippy::useless_transmute)]

#[clippy::cyclomatic_complexity = "100"]

--------------------------------------------------------------------------------

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    (attribute
      (identifier)))
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    name: (identifier)
    parameters: (parameters)
    body: (block))
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      (identifier)
      arguments: (token_tree
        (identifier))))
  (struct_item
    name: (type_identifier))
  (attribute_item
    (attribute
      (identifier)
      arguments: (token_tree
        (identifier)
        (identifier))))
  (struct_item
    name: (type_identifier))
  (attribute_item
    (attribute
      (identifier)
      arguments: (token_tree
        (identifier)
        (string_literal))))
  (mod_item
    name: (identifier)
    body: (declaration_list))
  (inner_attribute_item
    (attribute
      (identifier)
      arguments: (token_tree
        (identifier)
        (identifier))))
  (attribute_item
    (attribute
      (scoped_identifier
        path: (identifier)
        name: (identifier))
      value: (string_literal))))

================================================================================
Inner attributes
================================================================================

mod macos_only {
  #![cfg(target_os = "macos")]
}

--------------------------------------------------------------------------------

(source_file
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    name: (identifier)
    body: (declaration_list
      (inner_attribute_item
        (attribute
          (identifier)
          arguments: (token_tree
            (identifier)
            (string_literal)))))))

================================================================================
Key-Value Attribute Expressions
================================================================================

#[doc = include_str!("foo-doc.md")]
fn foo() {}

#[namespace = foo::bar]
fn baz() {}

--------------------------------------------------------------------------------

(source_file
  (attribute_item
    (attribute
      (identifier)
      (macro_invocation
        (identifier)
        (token_tree
          (string_literal)))))
  (function_item
    (identifier)
    (parameters)
    (block))
  (attribute_item
    (attribute
      (identifier)
      (scoped_identifier
        (identifier)
        (identifier))))
  (function_item
    (identifier)
    (parameters)
    (block)))

================================================================================
Attribute macros
================================================================================

foo(#[attr(=> arbitrary tokens <=)] x, y);

foo(#[bar(some tokens are special in other contexts: $/';()*()+.)] x);

--------------------------------------------------------------------------------

(source_file
  (expression_statement
    (call_expression
      function: (identifier)
      arguments: (arguments
        (attribute_item
          (attribute
            (identifier)
            arguments: (token_tree
              (identifier)
              (identifier))))
        (identifier)
        (identifier))))
  (expression_statement
    (call_expression
      function: (identifier)
      arguments: (arguments
        (attribute_item
          (attribute
            (identifier)
            arguments: (token_tree
              (identifier)
              (identifier)
              (identifier)
              (identifier)
              (identifier)
              (identifier)
              (identifier)
              (token_tree)
              (token_tree))))
        (identifier)))))

================================================================================
Derive macro helper attributes
================================================================================

// Example from https://github.com/dtolnay/thiserror/blob/21c26903e29cb92ba1a7ff11e82ae2001646b60d/README.md

use thiserror::Error;

#[derive(Error, Debug)]
pub enum Error {
    #[error("first letter must be lowercase but was {:?}", first_char(.0))]
    WrongCase(String),
    #[error("invalid index {idx}, expected at least {} and at most {}", .limits.lo, .limits.hi)]
    OutOfBounds { idx: usize, limits: Limits },
}

--------------------------------------------------------------------------------

(source_file
  (line_comment)
  (use_declaration
    (scoped_identifier
      (identifier)
      (identifier)))
  (attribute_item
    (attribute
      (identifier)
      (token_tree
        (identifier)
        (identifier))))
  (enum_item
    (visibility_modifier)
    (type_identifier)
    (enum_variant_list
      (attribute_item
        (attribute
          (identifier)
          (token_tree
            (string_literal)
            (identifier)
            (token_tree
              (integer_literal)))))
      (enum_variant
        (identifier)
        (ordered_field_declaration_list
          (type_identifier)))
      (attribute_item
        (attribute
          (identifier)
          (token_tree
            (string_literal)
            (identifier)
            (identifier)
            (identifier)
            (identifier))))
      (enum_variant
        (identifier)
        (field_declaration_list
          (field_declaration
            (field_identifier)
            (primitive_type))
          (field_declaration
            (field_identifier)
            (type_identifier)))))))

================================================================================
Attributes and Expressions
================================================================================

fn foo() {
   bar(x,
       #[cfg(foo = "bar")]
       y);
   let z = [#[hello] 2, 7, 8];
   let t = (#[hello] 2, 7, 8);
}

--------------------------------------------------------------------------------

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    name: (identifier)
    parameters: (parameters)
    body: (block
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          arguments: (arguments
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            (attribute
              (identifier)))
          (integer_literal)
          (integer_literal)
          (integer_literal))))))

================================================================================
Inherent Impls
================================================================================

impl Person {
  const leg_count : u32 = 2;

  fn walk(self) {}
  fn walk_mut(mut self) {}
  fn talk(& self) {}
  fn talk_mut(&'a mut self) {}
}

impl Machine<{State::Init}> {}

--------------------------------------------------------------------------------

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          (scoped_identifier
            path: (identifier)
            name: (identifier)))))
    body: (declaration_list)))

================================================================================
Trait impls
================================================================================

impl<'a> iter::Iterator for Self::Iter<'a> {
}

impl ConvertTo<i64> for i32 {
    fn convert(&self) -> i64 { *self as i64 }
}

--------------------------------------------------------------------------------

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        return_type: (primitive_type)
        body: (block
          (type_cast_expression
            value: (unary_expression
              (self))
            type: (primitive_type)))))))

================================================================================
Unsafe impls
================================================================================

unsafe impl Foo {
}

--------------------------------------------------------------------------------

(source_file
  (impl_item
    (type_identifier)
    (declaration_list)))

================================================================================
Trait impl signature
================================================================================

impl<K: Debug + Ord> Debug for OccupiedError<K>;
impl<K: Debug + Ord> Display for OccupiedError<K>;

--------------------------------------------------------------------------------

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================================================================================
Impls with default functions
================================================================================

impl Foo {
  const default fn bar() -> i32 {
    // Make 'default' still works as an identifier
    default.bar();
  }
}

--------------------------------------------------------------------------------

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                (field_identifier))
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================================================================================
Trait declarations
================================================================================

pub trait Item: Clone + Eq + fmt::Debug {
    fn summarize(&self) -> Self::Summary;
}

unsafe trait Foo { }

--------------------------------------------------------------------------------

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================================================================================
Trait declarations with optional type parameters
================================================================================

trait Add<RHS=Self> {
    type Output;
    fn add(self, rhs: RHS) -> Self::Output;
}

--------------------------------------------------------------------------------

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          (type_identifier))))))

================================================================================
Unsized types in trait bounds
================================================================================

trait Foo<T: ?Sized> {
}

--------------------------------------------------------------------------------

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================================================================================
Macro invocations inside trait declarations
================================================================================


pub trait A: B + C + D {
    private_decl!{}
    fn f(&self);
}

--------------------------------------------------------------------------------

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      (function_signature_item
        (identifier)
        (parameters
          (self_parameter
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================================================================================
Associated Types
================================================================================

pub trait Graph {
    type N: fmt::Display;
    type E;
}

--------------------------------------------------------------------------------

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            (type_identifier))))
      (associated_type
        (type_identifier)))))

================================================================================
Generic Associated Types
================================================================================

pub trait Database {
    type F<'a, D>: Future<Output = D> + 'a;
}

impl Database for Foo {
    type F<'a, D> = DatabaseFuture<'a, D>;
}

fn use_database1<D: Database<F<'a, TD> = F>>() {}

fn use_database2<D>()
where
    D: Database<F<'a, TD> = F>,
{}

--------------------------------------------------------------------------------

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                  (type_identifier))
                (type_identifier)))))))
    (block)))

================================================================================
Higher-ranked types
================================================================================

trait T: for<'a> AddAssign<&'a usize> {
}

--------------------------------------------------------------------------------

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              (primitive_type))))))
    (declaration_list)))

================================================================================
Visibility modifiers
================================================================================

pub fn a() {}
pub(super) fn b() {}
pub(self) fn c() {}
pub(crate) fn c() {}
pub(in crate::d) fn e() {}

--------------------------------------------------------------------------------

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      (scoped_identifier
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        (identifier)))
    (identifier)
    (parameters)
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================================================================================
Function parameter names that match built-in type names
================================================================================

fn foo(str: *const c_char) {}
fn bar(bool: bool) {}

--------------------------------------------------------------------------------

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        (identifier)
        (primitive_type)))
    (block)))

================================================================================
Where clauses
================================================================================

fn walk<F>(&self, it: &mut F) -> bool
    where F: FnMut(&Pat) -> bool
{
  return false
}

impl<'a, T: 'a + Item> Iterator for Iter<'a, T> where Self: 'a {
}

impl<T> A for B<T>
    where C<T>: D,
          T: 'c,
          'c: 'b,
{
}

impl<'a, E> Read
where &'a E: Read,
{
}

impl<T> A for B<T> where (T, T, T): C, {}

impl<T> A for B<T>
    where for<'a> D<T>: E<'a>,
{
}

pub trait A<B> where B: C,
{
}

fn foo<A>() where A: B + As<f64>, f64: As<A> {}

impl<A> Default for B<A> where *mut A: C + D {}

--------------------------------------------------------------------------------

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    body: (declaration_list))
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        bounds: (trait_bounds
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    body: (declaration_list))
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            (lifetime
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              (type_identifier))))
        bounds: (trait_bounds
          (generic_type
            type: (type_identifier)
            type_arguments: (type_arguments
              (lifetime
                (identifier)))))))
    body: (declaration_list))
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    (visibility_modifier)
    name: (type_identifier)
    type_parameters: (type_parameters
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    (where_clause
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        left: (type_identifier)
        bounds: (trait_bounds
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    body: (declaration_list))
  (function_item
    name: (identifier)
    type_parameters: (type_parameters
      (type_identifier))
    parameters: (parameters)
    (where_clause
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        left: (type_identifier)
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          (generic_type
            type: (type_identifier)
            type_arguments: (type_arguments
              (primitive_type)))))
      (where_predicate
        left: (primitive_type)
        bounds: (trait_bounds
          (generic_type
            type: (type_identifier)
            type_arguments: (type_arguments
              (type_identifier))))))
    body: (block))
  (impl_item
    type_parameters: (type_parameters
      (type_identifier))
    trait: (type_identifier)
    type: (generic_type
      type: (type_identifier)
      type_arguments: (type_arguments
        (type_identifier)))
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      (where_predicate
        left: (pointer_type
          (mutable_specifier)
          type: (type_identifier))
        bounds: (trait_bounds
          (type_identifier)
          (type_identifier))))
    body: (declaration_list)))

================================================================================
External Modules
================================================================================

pub extern {
  pub fn napi_module_register(mod_: *mut napi_module);
}

extern "C" {}

--------------------------------------------------------------------------------

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  (foreign_mod_item
    (extern_modifier
      (string_literal))
    (declaration_list)))

================================================================================
Crate visibility
================================================================================

crate mod foo;
crate struct Foo(crate crate::Bar);
crate fn foo() { }
crate const X: u32 = 0;

--------------------------------------------------------------------------------

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        (type_identifier))))
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    (identifier)
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  (const_item
    (visibility_modifier
      (crate))
    (identifier)
    (primitive_type)
    (integer_literal)))

================================================================================
Reserved keywords in path
================================================================================

struct A {
  a: default::B,
  b: union::C,
}

--------------------------------------------------------------------------------

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      (field_declaration
        (field_identifier)
        (scoped_type_identifier
          (identifier)
          (type_identifier))))))

================================================================================
Array Constraint in Where Clause
================================================================================

fn foo<D>(val: D)
where   
    [u8; 32]: From<D>,

{}

--------------------------------------------------------------------------------

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    (identifier)
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          (primitive_type)
          (integer_literal))
        (trait_bounds
          (generic_type
            (type_identifier)
            (type_arguments
              (type_identifier))))))
    (block)))
