=======================================
Operator declarations
=======================================

class A
{
  [SomeAttribute]
  public static int operator +(A a) { return 0; }

  public static int operator +(A a, A b) { return 0; }

  int operator -(A a) { return 0; }
}

---

(compilation_unit
  (class_declaration
    (identifier)
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        (attribute_list (attribute (identifier)))
        (modifier) (modifier)
        (predefined_type)
        (parameter_list
          (parameter (identifier) (identifier)))
        (block (return_statement (integer_literal))))
      (operator_declaration
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        (predefined_type)
        (parameter_list
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          (parameter (identifier) (identifier)))
        (block (return_statement (integer_literal))))
      (operator_declaration
        (predefined_type)
        (parameter_list
          (parameter (identifier) (identifier)))
        (block (return_statement (integer_literal)))))))

=======================================
boolean operator declarations
=======================================

class A
{
  public static bool operator true(A a) { return true; }
  bool operator false(A a) { return false; }
}

---

(compilation_unit
  (class_declaration
    (identifier)
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        (block (return_statement (boolean_literal))))
      (operator_declaration
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        (parameter_list
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        (block (return_statement (boolean_literal)))))))

=======================================
conversion operator declaration
=======================================

class A
{
  public static implicit operator int (A a) { return 0; }
  explicit operator int (A a) { return 0; }
}

---

(compilation_unit
  (class_declaration
    (identifier)
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        (block (return_statement (integer_literal))))
      (conversion_operator_declaration
        (predefined_type)
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        (block (return_statement (integer_literal)))))))

=======================================
conversion operator with expression body
=======================================

class A
{
  public static implicit operator int (A a) => 0;
}

---

(compilation_unit
  (class_declaration
    (identifier)
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        (arrow_expression_clause (integer_literal))))))

=======================================
extern operators
=======================================

class A
{
  public static extern int operator + (A a);
  public static extern bool operator <(A a, A b);
  public static explicit operator int (A a);
}

---

(compilation_unit
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      (operator_declaration
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=======================================
Class conversion operators with expression body
=======================================

class A
{
  public static extern int operator + (A a) => 0;
  public static extern bool operator <(A a, A b) => true;
  public static explicit operator int (A a) => 0;
}

---

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