typededuction.h

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/*
creg - Code compoment registration system
Copyright 2005 Jelmer Cnossen 

Type matching using class templates (only class template support partial specialization)
*/

// Undefined types return 0
template<typename T>
struct DeduceType {
	IType* Get () { return IType::CreateObjInstanceType(T::StaticClass()); }
};

template<typename T>
struct IsBasicType {
	enum {Yes=0, No=1};
};

// Support for a number of fundamental types
#define CREG_SUPPORT_BASIC_TYPE(T, typeID)			\
	template <>	 struct DeduceType <T> {		\
		IType* Get () { return IType::CreateBasicType (typeID); }	\
	};																\
	template <> struct IsBasicType <T> {							\
		enum {Yes=1, No=0 };										\
	};

CREG_SUPPORT_BASIC_TYPE(int, crInt)
CREG_SUPPORT_BASIC_TYPE(unsigned int, crUInt)
CREG_SUPPORT_BASIC_TYPE(short, crShort)
CREG_SUPPORT_BASIC_TYPE(unsigned short, crUShort)
CREG_SUPPORT_BASIC_TYPE(char, crChar)
CREG_SUPPORT_BASIC_TYPE(unsigned char, crUChar)
CREG_SUPPORT_BASIC_TYPE(long, crInt) // Long is assumed to be an int (4 bytes)
CREG_SUPPORT_BASIC_TYPE(unsigned long, crUInt)
CREG_SUPPORT_BASIC_TYPE(float, crFloat)
CREG_SUPPORT_BASIC_TYPE(double, crDouble)
CREG_SUPPORT_BASIC_TYPE(bool, crBool)

#if defined(SYNCDEBUG) || defined(SYNCCHECK)
CREG_SUPPORT_BASIC_TYPE(SyncedSint,   crSyncedSint)
CREG_SUPPORT_BASIC_TYPE(SyncedUint,   crSyncedUint)
CREG_SUPPORT_BASIC_TYPE(SyncedSshort, crSyncedSshort)
CREG_SUPPORT_BASIC_TYPE(SyncedUshort, crSyncedUshort)
CREG_SUPPORT_BASIC_TYPE(SyncedSchar,  crSyncedSchar)
CREG_SUPPORT_BASIC_TYPE(SyncedUchar,  crSyncedUchar)
CREG_SUPPORT_BASIC_TYPE(SyncedSlong,  crSyncedSint) // Long is assumed to be an int (4 bytes)
CREG_SUPPORT_BASIC_TYPE(SyncedUlong,  crSyncedUint)
CREG_SUPPORT_BASIC_TYPE(SyncedFloat,  crSyncedFloat)
CREG_SUPPORT_BASIC_TYPE(SyncedDouble, crSyncedDouble)
CREG_SUPPORT_BASIC_TYPE(SyncedBool,   crSyncedBool)
#endif


template<typename T>
class ObjectPointerType : public IType
{
public:
	ObjectPointerType() { objectClass = T::StaticClass(); }
	void Serialize (ISerializer *s, void *instance) {
		void **ptr = (void**)instance;
		if (s->IsWriting())
			s->SerializeObjectPtr (ptr, *ptr ? ((T*)*ptr)->GetClass () : 0);
		else s->SerializeObjectPtr (ptr, objectClass);
	}
	std::string GetName() { return objectClass->name + "*"; }
	Class* objectClass;
};

// Pointer type
template<typename T>
struct DeduceType <T *> {
	IType* Get () { return new ObjectPointerType <T>(); }
};

// Reference type, handled as a pointer
template<typename T>
struct DeduceType <T&> {
	IType* Get () { return new ObjectPointerType <T>(); }
};

// Static array type
template<typename T, size_t ArraySize>
struct DeduceType <T[ArraySize]> {
	IType* Get () { 
		DeduceType<T> subtype;
		return new StaticArrayType <T, ArraySize> (subtype.Get());
	}
};

// Vector type (vector<T>)
template<typename T>
struct DeduceType < std::vector <T> > {
	IType* Get () { 
		DeduceType<T> elemtype;
		return new DynamicArrayType < std::vector<T> > (elemtype.Get());
	}
};

// String type
template<> struct DeduceType < std::string > {
	IType* Get () { return IType::CreateStringType (); }
};

// GetType allows to use parameter type deduction to get the template argument for DeduceType
template<typename T>
IType* GetType (T& var) {
	DeduceType<T> deduce;
	return deduce.Get();
}