X-Git-Url: http://git.tdb.fi/?p=libs%2Fcore.git;a=blobdiff_plain;f=source%2Fcore%2Fmaputils.h;h=f5faa1271a2e1317523767c5e9c3e6a858792027;hp=1a7c0ae6ce8e952d1ab9b10113e47172dc4b3136;hb=f24e7b96e76b63c9b9b8a6bce4c7a9db64276ea8;hpb=9519381422961a538a3ebbd1e6563d170215f14e

diff --git a/source/core/maputils.h b/source/core/maputils.h
index 1a7c0ae..f5faa12 100644
--- a/source/core/maputils.h
+++ b/source/core/maputils.h
@@ -3,22 +3,63 @@
 
 #include <stdexcept>
 #include <typeinfo>
+#include <msp/strings/lexicalcast.h>
 
 namespace Msp {
 
+namespace MapUtilsInternal {
+
+/* This dummy struct is used to introduce a conversion, making the overloaded
+operator below worse than the templated one provided in lexicalcast.h. */
+struct Any
+{
+	template<typename T>
+	Any(const T &) { }
+};
+
+/* This must be hidden in the internal namespace to avoid interfering with
+other things. */
+inline void operator<<(LexicalConverter &, Any)
+{ }
+
+template<typename T>
+static std::string stringify_key(const T &k)
+{
+	try
+	{
+		LexicalConverter conv((Fmt()));
+		conv<<k;
+		return conv.get();
+	}
+	catch(const lexical_error &)
+	{
+		return "<cannot display value>";
+	}
+}
+
+} // namespace Internal
+
 class key_error: public std::runtime_error
 {
 public:
-	key_error(const std::type_info &);
+	template<typename T>
+	key_error(const T &k):
+		runtime_error(make_what(typeid(T), MapUtilsInternal::stringify_key(k)))
+	{ }
+
+	virtual ~key_error() throw() { }
+
+private:
+	static std::string make_what(const std::type_info &, const std::string &);
 };
 
 
 template<typename T>
 typename T::mapped_type &get_item(T &map, const typename T::key_type &key)
 {
-	typename T::iterator i = map.find(key);
+	auto i = map.find(key);
 	if(i==map.end())
-		throw key_error(typeid(T));
+		throw key_error(key);
 
 	return i->second;
 }
@@ -26,13 +67,37 @@ typename T::mapped_type &get_item(T &map, const typename T::key_type &key)
 template<typename T>
 const typename T::mapped_type &get_item(const T &map, const typename T::key_type &key)
 {
-	typename T::const_iterator i = map.find(key);
+	auto i = map.find(key);
 	if(i==map.end())
-		throw key_error(typeid(T));
+		throw key_error(key);
 
 	return i->second;
 }
 
+template<typename D, typename T>
+D *get_item(const T &map, const typename T::key_type &key)
+{
+	return dynamic_cast<D *>(get_item(map, key));
+}
+
+template<typename T>
+typename T::iterator insert_unique(T &map, const typename T::key_type &key, const typename T::mapped_type &item)
+{
+	if(map.count(key))
+		throw key_error(key);
+
+	return map.insert(std::make_pair(key, item)).first;
+}
+
+template<typename T>
+void remove_existing(T &map, const typename T::key_type &key)
+{
+	if(!map.count(key))
+		throw key_error(key);
+
+	map.erase(key);
+}
+
 } // namespace Msp
 
 #endif