-/* $Id$
-
-This file is part of libmspcore
-Copyright © 2006-2007 Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
#ifndef MSP_CORE_VARIANT_H_
#define MSP_CORE_VARIANT_H_
-#include "except.h"
+#include <stdexcept>
+#include <typeinfo>
+#include "meta.h"
namespace Msp {
+class type_mismatch: public std::runtime_error
+{
+public:
+ type_mismatch(const std::type_info &, const std::type_info &);
+ ~type_mismatch() throw() { }
+};
+
+
class Variant
{
private:
struct StoreBase
{
virtual ~StoreBase() { }
+
+ virtual const std::type_info &type_id() const = 0;
+ virtual StoreBase *clone() const = 0;
};
template<typename T>
{
T data;
- Store(T d): data(d) { }
+ Store(const T &d): data(d) { }
+
+ virtual const std::type_info &type_id() const { return typeid(T); }
+ virtual StoreBase *clone() const { return new Store<T>(data); }
};
StoreBase *store;
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(const Variant &v): store(v.store ? v.store->clone() : 0) { }
~Variant() { delete store; }
template<typename T>
- Variant &operator=(T v)
+ Variant &operator=(const T &v)
+ {
+ delete store;
+ store = new Store<typename RemoveConst<T>::Type>(v);
+ return *this;
+ }
+
+ Variant &operator=(const Variant &v)
{
delete store;
- store=new Store<T>(v);
+ store = (v.store ? v.store->clone() : 0);
return *this;
}
+private:
template<typename T>
- T value() const
+ Store<typename RemoveConst<T>::Type> *get_typed_store() 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;
+ throw type_mismatch(typeid(T), (store ? store->type_id() : typeid(void)));
+ return s;
+ }
+
+public:
+ template<typename T>
+ T &value()
+ {
+ return get_typed_store<T>()->data;
+ }
+
+ template<typename T>
+ const T &value() const
+ {
+ return get_typed_store<T>()->data;
}
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>