Сделал симуляцию указателей на функцию. Sort.mqh:
#property strict class SORT { private: template <typename T> static void Swap( T &Array[], const int i, const int j ) { const T Temp = Array[i]; Array[i] = Array[j]; Array[j] = Temp; return; } template<typename T1, typename T2> static int Partition( T1 &Array[], const T2 &Compare, const int Start, const int End ) { int Marker = Start; for (int i = Start; i <= End; i++) if (Compare.Compare(Array[i], Array[End]) <= 0) { Swap(Array, i, Marker); Marker++; } return(Marker - 1); } template<typename T1, typename T2> static void QuickSort( T1 &Array[], const T2 &Compare, const int Start, const int End ) { if (Start < End) { const int Pivot = Partition(Array, Compare, Start, End); QuickSort(Array, Compare, Start, Pivot - 1); QuickSort(Array, Compare, Pivot + 1, End); } return; } public: /* синтаксис почти соответствует MQL-штатной ArraySort: void& array[] // массив для сортировки void& Compare // условие сортировки (с направлением) int count = WHOLE_ARRAY, // количество элементов int start = 0, // начальный индекс */ template<typename T1, typename T2> static void Sort( T1 &Array[], const T2 Compare, int Count = WHOLE_ARRAY, const int Start = 0 ) { if (Count == WHOLE_ARRAY) Count = ArraySize(Array); if (CheckPointer(Compare) != POINTER_INVALID) QuickSort(Array, Compare, Start, Start + Count - 1); if (CheckPointer(Compare) == POINTER_DYNAMIC) delete Compare; return; } }; class COMPARE { private: const int Mode; protected: template <typename T> T SetMode( T Value ) const { if (Mode != MODE_ASCEND) Value = -Value; return(Value); } public: COMPARE( const int iMode = MODE_ASCEND ): Mode(iMode) { } template<typename T> T Compare( const T First, const T Second ) const { return(SetMode(First - Second)); } };
Вот так теперь можно делать кастомную сортировку массивов из любых объектов:
#property strict #include <Sort.mqh> template <typename T> void PrintArray( const T &Array[] ) { const int Size = ArraySize(Array); string Str = ""; for (int i = 0; i < Size; i++) Str = Str + " " + (string)Array[i]; Print(Str); } class CompareByAbs : public COMPARE { public: template<typename T> T Compare( const T First, const T Second ) const { return(SetMode( MathAbs(First) - MathAbs(Second) // условие сортировки )); } CompareByAbs( const int iMode = MODE_ASCEND ) : COMPARE(iMode) // можно не прописывать (для возможности обратной сортировки) { } }; void OnStart( void ) { int Array[] = {2, -45, 1, -5, 7, 9}; SORT::Sort(Array, new COMPARE); PrintArray(Array); // -45 -5 1 2 7 9 SORT::Sort(Array, new CompareByAbs(MODE_DESCEND)); PrintArray(Array); // -45 9 7 -5 2 1 return; }
aforexpert:
It's said in MQL4 Reference that "Function templates can also be used for class methods". Then I tried th folwing code:
Compiler says: template functions overloading is not supported yet...
Does anybody successfully do template functions in a class?
You have to duplicate the template statement :
class CTest { private: public: CTest(); ~CTest(); template<typename T> void Func(T &data); }; CTest::CTest() { } CTest::~CTest() { } //+------------------------------------------------------------------+ template<typename T> CTest::Func(T &data) { } //+------------------------------------------------------------------+
angevoyageur:
Thank you very much! I duplicate the template statement and it works! ;)
You have to duplicate the template statement :
Sergey Dzyublik:
Thank you!
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It's said in MQL4 Reference that "Function templates can also be used for class methods". Then I tried th folwing code:
Compiler says: template functions overloading is not supported yet...
Does anybody successfully do template functions in a class?