diff --git a/Collection/SortComparer.mqh b/Collection/SortComparer.mqh
new file mode 100644
index 0000000..4b4283f
--- /dev/null
+++ b/Collection/SortComparer.mqh
@@ -0,0 +1,49 @@
+//+------------------------------------------------------------------+
+//| Module: Collection/SortComparer.mqh                              |
+//| This file is part of the mql4-lib project:                       |
+//|     https://github.com/dingmaotu/mql4-lib                        |
+//|                                                                  |
+//| Copyright 2017 Li Ding <dingmaotu@126.com>                       |
+//| Copyright 2017 Yerden Zhumabekov <yerden.zhumabekov@gmail.com>   |
+//|                                                                  |
+//| Licensed under the Apache License, Version 2.0 (the "License");  |
+//| you may not use this file except in compliance with the License. |
+//| You may obtain a copy of the License at                          |
+//|                                                                  |
+//|     http://www.apache.org/licenses/LICENSE-2.0                   |
+//|                                                                  |
+//| Unless required by applicable law or agreed to in writing,       |
+//| software distributed under the License is distributed on an      |
+//| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,     |
+//| either express or implied.                                       |
+//| See the License for the specific language governing permissions  |
+//| and limitations under the License.                               |
+//+------------------------------------------------------------------+
+#include "../Lang/Hash.mqh"
+#include "EqualityComparer.mqh"
+#property strict
+//+------------------------------------------------------------------+
+//| Sort comparer is useful for sorted sets, arrays etc.       |
+//+------------------------------------------------------------------+
+template<typename T>
+class SortComparer: public EqualityComparer<T>
+  {
+   // Sort comparison:
+   //    >0 if left>right
+   //    <0 if left<right
+   //   ==0 if left==right
+public:
+   virtual int       compare(const T left,const T right) const=0;
+   virtual bool      equals(const T left,const T right) const override {return compare(left,right)==0;}
+  };
+//+------------------------------------------------------------------+
+//| Generic sort comparer for conventional comparable types          |
+//+------------------------------------------------------------------+
+template<typename T>
+class GenericSortComparer: public SortComparer<T>
+  {
+public:
+   virtual int       compare(const T left,const T right) const override {return left<right?-1:left>right;}
+   virtual int       hash(const T value) const override {return Hash(value);}
+  };
+//+------------------------------------------------------------------+
diff --git a/Collection/SortedArray.mqh b/Collection/SortedArray.mqh
new file mode 100644
index 0000000..07ef5b2
--- /dev/null
+++ b/Collection/SortedArray.mqh
@@ -0,0 +1,170 @@
+//+------------------------------------------------------------------+
+//| Module: Collection/SortedArray.mqh                               |
+//| This file is part of the mql4-lib project:                       |
+//|     https://github.com/dingmaotu/mql4-lib                        |
+//|                                                                  |
+//| Copyright 2015-2016 Li Ding <dingmaotu@126.com>                  |
+//| Copyright 2018 Yerden Zhumabekov <yerden.zhumabekov@gmail.com    |
+//|                                                                  |
+//| Licensed under the Apache License, Version 2.0 (the "License");  |
+//| you may not use this file except in compliance with the License. |
+//| You may obtain a copy of the License at                          |
+//|                                                                  |
+//|     http://www.apache.org/licenses/LICENSE-2.0                   |
+//|                                                                  |
+//| Unless required by applicable law or agreed to in writing,       |
+//| software distributed under the License is distributed on an      |
+//| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,     |
+//| either express or implied.                                       |
+//| See the License for the specific language governing permissions  |
+//| and limitations under the License.                               |
+//+------------------------------------------------------------------+
+#property strict
+
+#include "../Lang/Array.mqh"
+#include "SortComparer.mqh"
+#include "Collection.mqh"
+//+------------------------------------------------------------------+
+//| Simple Array-based implementation of sorted sets                 |
+//+------------------------------------------------------------------+
+template<typename T>
+class SortedArray: public Collection<T>
+  {
+private:
+   SortComparer<T>*m_sorter;
+   Array<T>m_array;
+   bool              m_unique;
+   bool              bsearch(const T value,int &id) const;
+public:
+   // owned: flag restricts destructor to delete array elements
+   // unique: flag allows add()-ing of identical elements
+   // sorter: array sorting implementation
+                     SortedArray(bool owned=true,bool unique=true,SortComparer<T>*sorter=NULL):
+                                                              Collection(owned,sorter),
+   m_unique(unique),
+   m_sorter(sorter==NULL?new GenericSortComparer<T>():sorter){}
+                    ~SortedArray() {SafeDelete(m_sorter);}
+
+   // ConstIterator interface
+   ConstIterator<T>*constIterator() const {return new ConstSortedArrayIterator<T>(GetPointer(this));}
+   // Iterator interface
+   Iterator<T>*iterator() {return new SortedArrayIterator<T>(GetPointer(this),m_owned);}
+
+   // Collection interface
+   void              clear() {m_array.clear();}
+   bool              add(T value);
+   bool              remove(const T value);
+   int               size() const {return m_array.size();}
+   bool              contains(const T value) const {return index(value)>=0;}
+
+   // SortedArray specific
+   T                 operator[](const int index) const {return m_array[index];}
+   // return index of a matched element, or <0 if not contained
+   int               index(const T value) const {int id=0;return bsearch(value,id)?id:-1;}
+   int               removeIndices(const int &removed[])
+     {
+      if(m_owned)
+         for(int i=0; i<ArraySize(removed); i++)
+            SafeDelete(m_array[removed[i]]);
+      return m_array.removeBatch(removed);
+     }
+  };
+//+------------------------------------------------------------------+
+//| Find value in set. Return true if found.                         |
+//| Set &id to element index if found or the appropriate             |
+//| position for insertion.                                          |
+//+------------------------------------------------------------------+
+template<typename T>
+bool SortedArray::bsearch(const T value,int &id) const
+  {
+   int cmp=1,l=0,u=m_array.size();
+
+   while(l<u)
+     {
+      int idx=l+(u-l)/2;
+      cmp=m_sorter.compare(value,m_array[idx]);
+      if(cmp<0) u=idx;
+      else if(cmp>0) l=idx+1;
+      else u=l=idx;
+     }
+
+   id=u;
+   return cmp==0;
+  }
+//+------------------------------------------------------------------+
+//| Add value to sorted array                                        |
+//+------------------------------------------------------------------+
+template<typename T>
+bool SortedArray::add(T value)
+  {
+   int id;
+   bool res=!bsearch(value,id);
+   res=res || !m_unique;
+   if(res) m_array.insertAt(id,value);
+   return res;
+  }
+//+------------------------------------------------------------------+
+//| Remove value from sorted array                                   |
+//+------------------------------------------------------------------+
+template<typename T>
+bool SortedArray::remove(const T value)
+  {
+   int id;
+   if(!bsearch(value,id))
+      return false;
+   T ovalue=m_array[id];
+   m_array.removeAt(id);
+   if(m_owned) SafeDelete(ovalue);
+   return true;
+  }
+//+------------------------------------------------------------------+
+//| ConstIterator implementation for SortedArray                     |
+//+------------------------------------------------------------------+
+template<typename T>
+class ConstSortedArrayIterator: public ConstIterator<T>
+  {
+private:
+   int               m_index;
+   const int         m_size;
+   const             SortedArray<T>*m_sortedarray;
+public:
+                     ConstSortedArrayIterator(const SortedArray<T>*v):m_index(0),m_size(v.size()),m_sortedarray(v) {}
+   bool              end() const {return m_index>=m_size;}
+   void              next() {if(!end()){m_index++;}}
+   T                 current() const {return m_sortedarray[m_index];}
+  };
+//+------------------------------------------------------------------+
+//| Iterator implementation for SortedArray                          |
+//+------------------------------------------------------------------+
+template<typename T>
+class SortedArrayIterator: public Iterator<T>
+  {
+private:
+   int               m_index;
+   const int         m_size;
+   SortedArray<T>*m_sortedarray;
+   int               m_removed[];
+protected:
+   bool              removed() const
+     {
+      int s=ArraySize(m_removed);
+      return (s>0 && m_removed[s-1]==m_index);
+     }
+public:
+                     SortedArrayIterator(SortedArray<T>*v,bool owned):m_index(0),m_size(v.size()),m_sortedarray(v){}
+                    ~SortedArrayIterator() {if(ArraySize(m_removed)>0) m_sortedarray.removeIndices(m_removed);}
+   bool              end() const {return m_index>=m_size;}
+   void              next() {if(!end()){m_index++;}}
+   T                 current() const {if(removed()) return NULL; else return m_sortedarray[m_index];}
+
+   bool              set(T value) {return false;} // unapplicable
+   bool              remove()
+     {
+      if(end()||removed()) return false;
+      int s=ArraySize(m_removed);
+      ArrayResize(m_removed,s+1,5);
+      m_removed[s]=m_index;
+      return true;
+     }
+  };
+//+------------------------------------------------------------------+
diff --git a/Lang/Array.mqh b/Lang/Array.mqh
index 762b679..ab6b6d5 100644
--- a/Lang/Array.mqh
+++ b/Lang/Array.mqh
@@ -21,6 +21,9 @@
 #property strict
 //+------------------------------------------------------------------+
 //| Generic array insert                                             |
+//| Inserts value at index into array.                               |
+//| Array expands to contain new element but only in case no holes   |
+//| appear in new array.                                             |
 //+------------------------------------------------------------------+
 template<typename T>
 void ArrayInsert(T &array[],int index,T value,int extraBuffer=10)
@@ -200,6 +203,7 @@ public:
    void              insertAt(int index,T value) {ArrayInsert(m_array,index,value,m_extraBuffer);}
    void              removeAt(int index) {ArrayDelete(m_array,index);}
    int               removeAll(const T value) {return ArrayDeleteAll(m_array,value);}
+   int               removeBatch(const int &removed[]) {return ArrayBatchRemove(m_array,removed);}
 
    int               index(const T value) const;
   };