From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 18 Jul 2012 14:43:19 +0000 (+0300)
Subject: Add facility for classes to specify what type they should be loaded as
X-Git-Url: http://git.tdb.fi/?p=libs%2Fdatafile.git;a=commitdiff_plain;h=818ead7b6ccef1e4d2435cc959bc07f910fcde46

Add facility for classes to specify what type they should be loaded as
---

diff --git a/source/type.h b/source/type.h
index a7c57c4..72d148a 100644
--- a/source/type.h
+++ b/source/type.h
@@ -31,18 +31,21 @@ struct FloatType
 {
 	static const char signature = 'f';
 	typedef double Store;
+	typedef Store Load;
 };
 
 struct BoolType
 {
 	static const char signature = 'b';
 	typedef bool Store;
+	typedef Store Load;
 };
 
 struct StringType
 {
 	static const char signature = 's';
 	typedef std::string Store;
+	typedef Store Load;
 };
 
 struct SymbolType
@@ -53,57 +56,79 @@ struct SymbolType
 };
 
 template<typename T>
-struct TypeInfo: SymbolType { };
+struct HasLoadType
+{
+	struct Yes { char c[2]; };
+	struct No { char c; };
+
+	template<typename U>
+	static Yes f(typename U::LoadType *);
+	template<typename U>
+	static No f(...);
+
+	enum { value = (sizeof(f<T>(0))==sizeof(Yes)) };
+};
+
+template<typename T, bool lt = HasLoadType<T>::value>
+struct TypeInfo;
 
 template<>
-struct TypeInfo<short int>: IntType { };
+struct TypeInfo<short int, false>: IntType { };
 
 template<>
-struct TypeInfo<unsigned short int>: IntType { };
+struct TypeInfo<unsigned short int, false>: IntType { };
 
 template<>
-struct TypeInfo<int>: IntType { };
+struct TypeInfo<int, false>: IntType { };
 
 template<>
-struct TypeInfo<unsigned int>: IntType { };
+struct TypeInfo<unsigned int, false>: IntType { };
 
 template<>
-struct TypeInfo<long int>: IntType { };
+struct TypeInfo<long int, false>: IntType { };
 
 template<>
-struct TypeInfo<unsigned long int>: IntType { };
+struct TypeInfo<unsigned long int, false>: IntType { };
 
 #ifdef MSVC
 template<>
-struct TypeInfo<__int64>: IntType { };
+struct TypeInfo<__int64, false>: IntType { };
 
 template<>
-struct TypeInfo<unsigned __int64>: IntType { };
+struct TypeInfo<unsigned __int64, false>: IntType { };
 #else
 template<>
-struct TypeInfo<long long int>: IntType { };
+struct TypeInfo<long long int, false>: IntType { };
 
 template<>
-struct TypeInfo<unsigned long long int>: IntType { };
+struct TypeInfo<unsigned long long int, false>: IntType { };
 #endif
 
 template<>
-struct TypeInfo<float>: FloatType { };
+struct TypeInfo<float, false>: FloatType { };
 
 template<>
-struct TypeInfo<double>: FloatType { };
+struct TypeInfo<double, false>: FloatType { };
 
 template<>
-struct TypeInfo<bool>: BoolType { };
+struct TypeInfo<bool, false>: BoolType { };
 
 template<>
-struct TypeInfo<std::string>: StringType { };
+struct TypeInfo<std::string, false>: StringType { };
+
+template<typename T>
+struct TypeInfo<const T, false>: TypeInfo<T> { };
+
+template<typename T>
+struct TypeInfo<T &, false>: TypeInfo<T> { };
 
 template<typename T>
-struct TypeInfo<const T>: TypeInfo<T> { };
+struct TypeInfo<T, true>: TypeInfo<typename T::LoadType>
+{ typedef typename T::LoadType Load; };
 
 template<typename T>
-struct TypeInfo<T &>: TypeInfo<T> { };
+struct TypeInfo<T, false>: SymbolType
+{ typedef T Load; };
 
 } // namespace DataFile
 } // namespace Msp
diff --git a/source/value.h b/source/value.h
index 78ec54a..e2b9fb1 100644
--- a/source/value.h
+++ b/source/value.h
@@ -25,7 +25,7 @@ public:
 	Value(Symbol d): sig(TypeInfo<Symbol>::signature), data(d) { }
 
 	template<typename T>
-	typename RemoveReference<T>::Type get() const
+	typename TypeInfo<T>::Load get() const
 	{ return get_<typename TypeInfo<T>::Store>(); }
 
 	char get_signature() const { return sig; }