From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 16 Oct 2007 19:48:31 +0000 (+0000)
Subject: Support const types with Collection properly
X-Git-Tag: 1.0~15
X-Git-Url: http://git.tdb.fi/?p=libs%2Fdatafile.git;a=commitdiff_plain;h=92644bf892df1220c8df67e1fc3da85dd02c53c5

Support const types with Collection properly
Delete old action in Loader if a new one replaces it
Add a namespace-scope load function taking an extra argument
---

diff --git a/source/collection.h b/source/collection.h
index 3a3b90e..85ca843 100644
--- a/source/collection.h
+++ b/source/collection.h
@@ -31,6 +31,14 @@ struct NeedsCollection
 	enum { result=(sizeof(f<T>(0))==sizeof(Yes)) };
 };
 
+template<typename T>
+struct RemoveConst
+{ typedef T Type; };
+
+template<typename T>
+struct RemoveConst<const T>
+{ typedef T Type; };
+
 /**
 A collection of objects that can be loaded from a datafile.  Each object is
 identified by a name, which must be unique across the entire collection.
@@ -167,7 +175,10 @@ private:
 	ItemKeywordSeq keywords;
 	ItemCreatorSeq creators;
 
+	Collection(const Collection &);
+	Collection &operator=(const Collection &);
 public:
+	Collection() { }
 	virtual ~Collection();
 
 	/**
@@ -180,7 +191,7 @@ public:
 		if(items.count(name))
 			throw KeyError("Duplicate key '"+name+"' in collection");
 
-		items[name]=new Item<T>(d);
+		items[name]=new Item<typename RemoveConst<T>::Type>(d);
 	}
 
 	/**
@@ -189,11 +200,13 @@ public:
 	template<typename T>
 	T &get(const std::string &name) const
 	{
+		typedef typename RemoveConst<T>::Type NCT;
+
 		ItemMap::const_iterator i=items.find(name);
 		if(i==items.end())
 			throw KeyError("Item '"+name+"' not found in collection");
 
-		const Item<T> *item=dynamic_cast<const Item<T> *>(i->second);
+		const Item<NCT> *item=dynamic_cast<const Item<NCT> *>(i->second);
 		if(!item)
 			throw TypeError("Item '"+name+"' is not of correct type");
 
@@ -208,20 +221,22 @@ public:
 	template<typename T>
 	T &get(const std::string &name)
 	{
+		typedef typename RemoveConst<T>::Type NCT;
+
 		ItemMap::const_iterator i=items.find(name);
 		if(i==items.end())
 		{
 			for(ItemCreatorSeq::iterator j=creators.begin(); j!=creators.end(); ++j)
-				if(T *d=(*j)->create<T>(*this, name))
+				if(NCT *d=(*j)->create<NCT>(*this, name))
 				{
 					// We already know that the item didn't exist yet
-					items[name]=new Item<T>(d);
+					items[name]=new Item<NCT>(d);
 					return *d;
 				}
 			throw KeyError("Item '"+name+"' not found in collection");
 		}
 
-		const Item<T> *item=dynamic_cast<const Item<T> *>(i->second);
+		const Item<NCT> *item=dynamic_cast<const Item<NCT> *>(i->second);
 		if(!item)
 			throw TypeError("Item '"+name+"' is not of correct type");
 
diff --git a/source/loader.cpp b/source/loader.cpp
index cf1a5ac..0a9f68f 100644
--- a/source/loader.cpp
+++ b/source/loader.cpp
@@ -34,6 +34,18 @@ Loader::~Loader()
 		delete i->second;
 }
 
+void Loader::add(const string &k, LoaderAction *a)
+{
+	ActionMap::iterator i=actions.find(k);
+	if(i!=actions.end())
+	{
+		delete i->second;
+		i->second=a;
+	}
+	else
+		actions[k]=a;
+}
+
 void Loader::load_statement(const Statement &st)
 {
 	cur_st=&st;
diff --git a/source/loader.h b/source/loader.h
index da1da3a..8d26a41 100644
--- a/source/loader.h
+++ b/source/loader.h
@@ -239,40 +239,40 @@ protected:
 	*/
 	template<typename L>
 	void add(const std::string &k, void (L::*func)())
-	{ actions.insert(typename ActionMap::value_type(k, new LoaderFunc0<L>(func))); }
+	{ add(k, new LoaderFunc0<L>(func)); }
 
 	template<typename L, typename A0>
 	void add(const std::string &k, void (L::*func)(A0))
-	{ actions.insert(typename ActionMap::value_type(k, new LoaderFunc1<L, A0>(func))); }
+	{ add(k, new LoaderFunc1<L, A0>(func)); }
 
 	template<typename L, typename A0, typename A1>
 	void add(const std::string &k, void (L::*func)(A0, A1))
-	{ actions.insert(typename ActionMap::value_type(k, new LoaderFunc2<L, A0, A1>(func))); }
+	{ add(k, new LoaderFunc2<L, A0, A1>(func)); }
 
 	template<typename L, typename A0, typename A1, typename A2>
 	void add(const std::string &k, void (L::*func)(A0, A1, A2))
-	{ actions.insert(typename ActionMap::value_type(k, new LoaderFunc3<L, A0, A1, A2>(func))); }
+	{ add(k, new LoaderFunc3<L, A0, A1, A2>(func)); }
 
 	template<typename L, typename A0, typename A1, typename A2, typename A3>
 	void add(const std::string &k, void (L::*func)(A0, A1, A2, A3))
-	{ actions.insert(typename ActionMap::value_type(k, new LoaderFunc4<L, A0, A1, A2, A3>(func))); }
+	{ add(k, new LoaderFunc4<L, A0, A1, A2, A3>(func)); }
 
 	/**
 	Adds a keyword that is loaded into a variable of the loaded object.
 	*/
 	template<typename L, typename T0>
 	void add(const std::string &k, T0 L::*p0)
-	{ actions.insert(typename ActionMap::value_type(k, new LoadValue1<L, T0>(p0))); }
+	{ add(k, new LoadValue1<L, T0>(p0)); }
 
 	template<typename L, typename T0, typename T1>
 	void add(const std::string &k, T0 L::*p0, T1 L::*p1)
-	{ actions.insert(typename ActionMap::value_type(k, new LoadValue2<L, T0, T1>(p0, p1))); }
+	{ add(k, new LoadValue2<L, T0, T1>(p0, p1)); }
 
 	/**
 	Adds a keyword that is recognized but ignored.
 	*/
 	void add(const std::string &k)
-	{ actions.insert(ActionMap::value_type(k, 0)); }
+	{ add(k, 0); }
 
 	/**
 	Loads a sub-object from the statement being processed.  The Loader class of
@@ -328,6 +328,7 @@ private:
 	ActionMap       actions;
 	const Statement *cur_st;
 
+	void add(const std::string &, LoaderAction *);
 	void load_statement(const Statement &st);
 };
 
@@ -346,6 +347,18 @@ void load(T &obj, const std::string &fn)
 	loader.load(parser);
 }
 
+template<typename T, typename U>
+void load(T &obj, const std::string &fn, U arg)
+{
+	std::ifstream in(fn.c_str());
+	if(!in)
+		throw Exception("Couldn't open "+fn);
+
+	Parser parser(in, fn);
+	typename T::Loader loader(obj, arg);
+	loader.load(parser);
+}
+
 } // namespace DataFile
 } // namespace Msp