MFC Collection Utilities

This is a small library that enables developers to use MFC containers (arrays, lists, maps) with range-based for loops. The library consists of a single header that you include in your MFC projects.

How to use it

To be able to use the MFC containers in range-based for loops include the mfciterators.h header.

The following sample shows how to iterate over a CStringArray using range-based for loops.

#include "mfciterators.h"

void func(CStringArray const & arr)
{
   for(auto const & str : arr)
   {
      // do something with str
   }
}

For maps you get access to the content through a key-value pair that has two fields: key and value.

The following example shows how to iterate through a CMap<int, CString>.

#include "mfciterators.h"

CMap<int, CString> map;
map.SetAt(1, "one");
map.SetAt(2, "two");
map.SetAt(3, "three");
for(auto const & kvp : map)
{
   // do something with the key-value pair
   TRACE("%d-%s\n", kvp.key, kvp.value);
}

Motivation

C++11 added support for range-based for loops. They allow iterating over the elements of a range without an index.

std::vector<int> v = {1, 2, 3, 4, 5};
for(auto& e : v)
  e *= 2;

However, if you try the above with MFC containers you get some errors because the compiler is looking for a begin() and end() function that provides access to the first and last element of the range:

1>error C3312: no callable 'begin' function found for type 'CStringArray'
1>error C3312: no callable 'end' function found for type 'CStringArray'

MFC does not define such functions for its containers. The MFC Collections Utilities libraries provides this for all MFC containers.

Supported containers

Template collections

Arrays	Lists	Maps
CArray	CList	CMap
CTypedPtrArray	CTypedPtrList	CTypedPtrMap

Non-template collections

Arrays	Lists	Maps
CObArray	CObList	CMapPtrToWord
CByteArray	CPtrList	CMapPtrToPtr
CDWordArray	CStringList	CMapStringToOb
CPtrArray		CMapStringToPtr
CStringArray		CMapStringToString
CWordArray		CMapWordToOb
CUIntArray		CMapWordToPtr

Compiler support

The library requires Visual Studio 2012 or a newer version.

More examples

Arrays

CStringArray arr;
arr.Add("this");
arr.Add("is");
arr.Add("a");
arr.Add("sample");

for(auto & s : arr)
{
   s.MakeUpper();
}

CArray<int> arr;
arr.Add(1);
arr.Add(2);
arr.Add(3);
arr.Add(4);

for(auto const n : arr)
{
   std::cout << n << std::endl;
}

Lists

class CFoo
{
public:
   int value;

   CFoo(int const v): value(v) {}
};

CTypedPtrList<CPtrList, CFoo*> ptrlist;
ptrlist.AddTail(new CFoo(1));
ptrlist.AddTail(new CFoo(2));
ptrlist.AddTail(new CFoo(3));

for(auto & o : ptrlist)
   o->value *= 2;

CList<int> list;
list.AddTail(1);
list.AddTail(2);
list.AddTail(3);

auto const & clist = list;
for(auto const n : clist)
{
   std::cout << n << std::endl;
}

Maps

CMap<int, int, CString, CString> map;

map.SetAt(1, "one");
map.SetAt(2, "two");
map.SetAt(3, "three");

for(auto & kvp : map)
{
   kvp.value.MakeUpper();
}

for(auto const & kvp : map)
{
   CString temp;
   temp.Format("key=%d, value=%s", kvp.key, kvp.value);
}

CTypedPtrMap<CMapWordToPtr, WORD, CFoo*> map;

map.SetAt(1, new CFoo(1));
map.SetAt(2, new CFoo(2));
map.SetAt(3, new CFoo(3));

// do something with map

for(auto & kvp : map)
{
   delete kvp.value;
}