feat: introduce pointerof operation

Introduce pointerof operation and do some side-quests along the way.

Refs: #34
Closes: #17

furc/include/furc/ast/expression.hpp

@@ -113,6 +113,7 @@ enum class unaryop_expression_node_t {
     PostfixIncrement, /**< Postfix increment */
     PrefixDecrement,  /**< Prefix decrement */
     PostfixDecrement, /**< Postfix decrement */
+    Pointerof,        /**< Pointerof */
 };
 
 /**

furc/include/furc/front/token.hpp

@@ -147,16 +147,17 @@ static inline std::string operator+(const std::string& str, token_t type) {
  * @brief Keyword token.
  */
 enum class keyword_token {
-    None,    /**< None */
-    Func,    /**< `func` */
-    Return,  /**< `return` */
-    If,      /**< `if` */
-    Else,    /**< `else` */
-    While,   /**< `while` */
-    Import,  /**< `import` */
-    Native,  /**< `native` */
-    Public,  /**< `public` */
-    Private, /**< `private` */
+    None,      /**< None */
+    Func,      /**< `func` */
+    Return,    /**< `return` */
+    If,        /**< `if` */
+    Else,      /**< `else` */
+    While,     /**< `while` */
+    Import,    /**< `import` */
+    Native,    /**< `native` */
+    Public,    /**< `public` */
+    Private,   /**< `private` */
+    Pointerof, /**< `pointerof` */
 
     Int32, /**< `int32` */
 };
@@ -173,6 +174,7 @@ static inline std::ostream& operator<<(std::ostream& os, keyword_token keyword)
     case keyword_token::Native: return os << "native";
     case keyword_token::Public: return os << "public";
     case keyword_token::Private: return os << "private";
+    case keyword_token::Pointerof: return os << "pointerof";
     case keyword_token::Int32: return os << "int32";
     }
     return os;
@@ -190,6 +192,7 @@ static inline std::string operator+(const std::string& str, keyword_token keywor
     case keyword_token::Native: return str + "native";
     case keyword_token::Public: return str + "public";
     case keyword_token::Private: return str + "private";
+    case keyword_token::Pointerof: return str + "pointerof";
     case keyword_token::Int32: return str + "int32";
     }
     return str;