From 74935056c496814a3c9d1380437812536b159203 Mon Sep 17 00:00:00 2001
From: Adrian Kummerländer
Date: Thu, 6 Feb 2014 20:53:38 +0100
Subject: Converted detail::Result into general optional_ptr type * Added set
 member method overload for easier value modification * Idea: expand
 detail::optional_ptr into general optional type

---
 src/trie.h    | 28 ++++++++++++++++++----------
 src/utility.h | 32 +++++++++++++++++++-------------
 2 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/src/trie.h b/src/trie.h
index 629e724..6262ab3 100644
--- a/src/trie.h
+++ b/src/trie.h
@@ -39,22 +39,28 @@ class Trie {
 			return this->resolve(path);
 		}
 
-		inline detail::Result<Value*> get(key_list path) {
+		inline detail::optional_ptr<Value> get(key_list path) {
 			if ( auto tmp = this->resolve(path) ) {
 				if ( tmp.get()->value_.first ) {
-					return detail::Result<Value*>(&tmp.get()->value_.second);
+					return detail::optional_ptr<Value>(
+						&tmp.get()->value_.second
+					);
 				} else {
-					return detail::Result<Value*>();
+					return detail::optional_ptr<Value>();
 				}
 			} else {
-				return detail::Result<Value*>();
+				return detail::optional_ptr<Value>();
 			}
 		}
 
+		inline void set(Value value) {
+			this->value_.first  = true;
+			this->value_.second = value;
+		}
+
 		inline bool set(key_list path, Value value) {
 			if ( auto tmp = this->resolve(path) ) {
-				tmp.get()->value_.first  = true;
-				tmp.get()->value_.second = value;
+				tmp.get()->set(value);
 
 				return true;
 			} else {
@@ -105,11 +111,11 @@ class Trie {
 			}
 		}
 
-		inline detail::Result<Trie*> resolve(key_list path) {
+		inline detail::optional_ptr<Trie> resolve(key_list path) {
 			return this->resolve(path, path.begin());
 		}
 
-		inline detail::Result<Trie*> resolve(
+		inline detail::optional_ptr<Trie> resolve(
 			key_list& path,
 			typename key_list::const_iterator currStep
 		) {
@@ -123,12 +129,14 @@ class Trie {
 				);
 
 				if ( nextStep == path.end() ) {
-					return detail::Result<Trie*>(&(*matchingTrie).second);
+					return detail::optional_ptr<Trie>(
+						&(*matchingTrie).second
+					);
 				} else {
 					return (*matchingTrie).second.resolve(path, nextStep);
 				}
 			} else {
-				return detail::Result<Trie*>();
+				return detail::optional_ptr<Trie>();
 			}
 		}
 
diff --git a/src/utility.h b/src/utility.h
index 6342420..db33608 100644
--- a/src/utility.h
+++ b/src/utility.h
@@ -4,24 +4,30 @@
 namespace detail {
 
 template <
-	typename Value
+	typename Type
 >
-struct Result {
-	Result():
-		value_(false, Value()) { }
+class optional_ptr {
+	public:
+		typedef typename std::add_pointer<Type>::type pointer;
+		typedef Type element_type;
 
-	Result(Value value):
-		value_(true, value) { }
+		optional_ptr():
+			value_(false, nullptr) { }
 
-	inline operator bool() const {
-		return this->value_.first;
-	}
+		optional_ptr(pointer ptr):
+			value_(true, ptr) { }
 
-	inline Value get() const {
-		return this->value_.second;
-	}
+		inline operator bool() const {
+			return this->value_.first;
+		}
+
+		inline pointer get() const {
+			return this->value_.second;
+		}
+
+	private:
+		const std::pair<bool, pointer> value_;
 
-	const std::pair<bool, Value> value_;
 };
 
 }
-- 
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