From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 5 Aug 2008 06:33:56 +0000 (+0000)
Subject: Handle constness in Variant
X-Git-Tag: 1.0~2
X-Git-Url: http://git.tdb.fi/?p=libs%2Fcore.git;a=commitdiff_plain;h=3553d02ef9cf66ae5ff16dd0b129815f144857a1

Handle constness in Variant
Return a reference from Variant::value()
Add meta.h for metaprogramming stuff
---

diff --git a/source/core/meta.h b/source/core/meta.h
new file mode 100644
index 0000000..f12aede
--- /dev/null
+++ b/source/core/meta.h
@@ -0,0 +1,23 @@
+/* $Id$
+
+This file is part of libmspcore
+Copyright © 2008  Mikko Rasa, Mikkosoft Productions
+Distributed under the LGPL
+*/
+
+#ifndef MSP_CORE_META_H_
+#define MSP_CORE_META_H_
+
+namespace Msp {
+
+template<typename T>
+struct RemoveConst
+{ typedef T Type; };
+
+template<typename T>
+struct RemoveConst<const T>
+{ typedef T Type; };
+
+} // namespace Msp
+
+#endif
diff --git a/source/core/variant.h b/source/core/variant.h
index b81bb50..6425fbf 100644
--- a/source/core/variant.h
+++ b/source/core/variant.h
@@ -9,6 +9,7 @@ Distributed under the LGPL
 #define MSP_CORE_VARIANT_H_
 
 #include "except.h"
+#include "meta.h"
 
 namespace Msp {
 
@@ -33,21 +34,22 @@ private:
 public:
 	Variant(): store(0) { }
 	template<typename T>
-	Variant(T v): store(new Store<T>(v)) { }
+	Variant(const T &v): store(new Store<typename RemoveConst<T>::Type>(v)) { }
 	~Variant() { delete store; }
 
 	template<typename T>
-	Variant &operator=(T v)
+	Variant &operator=(const T &v)
 	{
 		delete store;
-		store=new Store<T>(v);
+		store=new Store<typename RemoveConst<T>::Type>(v);
 		return *this;
 	}
 
 	template<typename T>
-	T value() const
+	T &value() const
 	{
-		Store<T> *s=dynamic_cast<Store<T> *>(store);
+		typedef typename RemoveConst<T>::Type NCT;
+		Store<NCT> *s=dynamic_cast<Store<NCT> *>(store);
 		if(!s)
 			throw InvalidState("Type mismatch");
 		return s->data;
@@ -56,7 +58,7 @@ public:
 	template<typename T>
 	bool check_type() const
 	{
-		return dynamic_cast<Store<T> *>(store)!=0;
+		return dynamic_cast<Store<typename RemoveConst<T>::Type> *>(store)!=0;
 	}
 
 	template<typename T>