add iteration interface to config

solanaceae/util/config_model.hpp

@@ -2,6 +2,8 @@
 
 #include "./config_model.inl"
 
+#include <memory> // Q.Q
+
 // TODO: events?
 struct ConfigModelI {
 	~ConfigModelI(void) {}
@@ -35,6 +37,53 @@ struct ConfigModelI {
 	virtual CM_InternalOptional<int64_t> get_int(CM_ISV module, CM_ISV category) = 0;
 	virtual CM_InternalOptional<double> get_double(CM_ISV module, CM_ISV category) = 0;
 	virtual CM_InternalOptional<CM_ISV> get_string(CM_ISV module, CM_ISV category) = 0;
+
+	// iteration
+	// actual range cant be virtual
+	template<typename Type>
+	struct ConstEntryProxy {
+		struct ConstEntryIteratorI {
+			virtual ~ConstEntryIteratorI(void) {}
+			virtual std::unique_ptr<ConstEntryIteratorI> clone(void) = 0;
+			virtual bool equal(const ConstEntryIteratorI& other) const = 0;
+			virtual void incrementOne(void) = 0;
+			//virtual const Type& getValue(void) const = 0;
+			virtual Type getValue(void) const = 0;
+		};
+
+		// actual iterator cant be virtual
+		struct ConstEntryIterator {
+			std::unique_ptr<ConstEntryIteratorI> _value;
+
+			// conversion
+			//ConstEntryIterator(const std::unique_ptr<ConstEntryIteratorI>& other) { _value = other._value->clone(); }
+			ConstEntryIterator(std::unique_ptr<ConstEntryIteratorI>&& value) { _value = std::move(value); }
+
+			// copy
+			ConstEntryIterator(const ConstEntryIterator& other) { _value = other._value->clone(); }
+			ConstEntryIterator& operator=(const ConstEntryIterator& other) { _value = other._value->clone(); return *this; }
+
+			// move
+			ConstEntryIterator(ConstEntryIterator&& other) { _value = std::move(other._value); }
+
+			bool operator==(const ConstEntryIterator& other) const { return _value->equal(*other._value); }
+			bool operator!=(const ConstEntryIterator& other) const { return !operator==(other); }
+			ConstEntryIterator& operator++(void) { _value->incrementOne(); return *this; }
+			Type operator*(void) const { return _value->getValue(); }
+		};
+
+		ConstEntryIterator _begin;
+		ConstEntryIterator _end;
+
+		const ConstEntryIterator& begin(void) const { return _begin; }
+		const ConstEntryIterator& end(void) const { return _end; }
+	};
+
+	// level 3
+	virtual ConstEntryProxy<bool> entries_bool(CM_ISV module, CM_ISV category) const = 0;
+	virtual ConstEntryProxy<int64_t> entries_int(CM_ISV module, CM_ISV category) const = 0;
+	virtual ConstEntryProxy<double> entries_double(CM_ISV module, CM_ISV category) const = 0;
+	virtual ConstEntryProxy<CM_ISV> entries_string(CM_ISV module, CM_ISV category) const = 0;
 };