C ++のプロパティC ++の（プリプロセッサを使用せずに）

C ++のプロパティに触発

5分間の思考で、プリプロセッサディレクティブなしで行う方法、何かが現れました...

この「何か」が役立つか、怠inessを理解できるか。 多くの欠点があり、名前によるアクセスはありませんが、マクロはありません）

up ：getter-setter-クラスメソッドによって作成

#include <string> #include <map> #include <iostream> using namespace std; template<class B,class T> class DefineProperty { T value; B *that; typedef void (B::*SetterPtr)(const T&); typedef T (B::*GetterPtr)(const T&) const; void (B::*setter)( const T &val ); T (B::*getter)( const T &val ) const; public: DefineProperty() { setter = NULL; getter = NULL; that = NULL; } DefineProperty(B *self, GetterPtr get, SetterPtr set) { that = self; setter = set; getter = get; } DefineProperty(B *self, SetterPtr set, GetterPtr get) { that = self; setter = set; getter = get; } DefineProperty(B *self, GetterPtr get) { that = self; setter = NULL; getter = get; } DefineProperty(B *self, SetterPtr set) { that = self; setter = set; getter = NULL; } void operator = ( const T &val ) { set( val ); } void set( const T &val ) { value = val; if( setter ) (that->*setter)( val ); } operator T () const { return get(); } T get() const { if( getter ) return (that->*getter)(value); return value; } T field_get() const { return value; } void field_set( const T &val ) { value = val; } }; template<class T,class B> std::ostream& operator<<(std::ostream &out, const DefineProperty<T,B> &val) { out << (val.get()); return out; } class ClassWithProps { public: DefineProperty<ClassWithProps,int> Integer; DefineProperty<ClassWithProps,int> PlainInteger; DefineProperty<ClassWithProps,int> FakedInteger; DefineProperty<ClassWithProps,string> String; // Disable warning 4355 - use this pointer in ctor // There is no violation in this particular case #pragma warning( push ) #pragma warning( disable: 4355 ) ClassWithProps() // Getter-Setter declaration : Integer(this, &ClassWithProps::IntegerSetter), FakedInteger(this, &ClassWithProps::IntegerGetter), String(this, &ClassWithProps::StringGetter, &ClassWithProps::StringSetter) { } #pragma warning( pop ) private: void IntegerSetter( const int &value ) { cout << "Set(" << value << ")" << endl; Integer.field_set(value+1); } int IntegerGetter( const int &value ) const { return value * 2; } string StringGetter( const string &value ) const { return "I love " + value; } void StringSetter( const string &value ) { } }; int main(int argc, char* argv[]) { ClassWithProps props; // not getter/setter props.PlainInteger = 1; int plain = props.PlainInteger; // only setter props.Integer = 100; int real = props.Integer; // only getter props.FakedInteger = 100; int faked = props.FakedInteger; // getter and setter props.String = "habr"; string str = props.String; // allow to use ostream cout << "Faked integer = " << props.FakedInteger << endl; cout << props.String << endl; return 0; }