C / C++ / MFC

Can someone help me with the getting my ParseExact working? Though following guidance from MSDN site I am still incorrect with my syntax. The error I am receiving is the following:
Error C2665: 'System::DateTime::ParseExact' : none of the 3 overloads could convert all the argument types.
C2665- Error Description: 'function' : none of the number1 overloads can convert parameter number2 from type 'type'

#include <stdio.h>
#include <vcclr.h>
#include <windows.h>
#include <string>

#using <mscorlib.dll>

using namespace std;
using namespace System;
using namespace System::Globalization;
using namespace System::Collections;

void main()
	{
	//System::Collections::IEnumerator^ en = CultureInfo::GetCultures(CultureTypes::SpecificCultures)->GetEnumerator();
	//System::Globalization::CultureInfo^ MyCI = gcnew CultureInfo("en-US",false);
	//System::Globalization::DateTimeFormatInfo^ myDTFI = MyCI->DateTimeFormat;				
		
	std::string dateString = "MAY_03_2010";
	std::string format = "MMM_dd_yyyy";
	//	DateTime dt = DateTime::Now;	
	DateTime dateTime = DateTime::ParseExact(dateString,format,nullptr);
	//System::DateTime dateTimevalue = System::DateTime::ParseExact(dateString,"MMMddyyyy",CultureInfo.InvariantCulture); 

	system("pause");
}

class CTVItemDataMMap
    :public std::multimap<LONG, CTVItemData>
    ,public CLockableCS
{
public:
	CTVItemDataMMap(){}

CTVItemDataMMap(CTVItemDataMMap& rhs)
{
	insert(rhs.begin(), rhs.end()); // <-- Here I got error
}

~CTVItemDataMMap(){}

};

typedef std::multimap<LONG, CTVItemData>& TVITEMDATA_MMAP_REF;

TVItemDataMgr.cpp
d:\vc++\dlgbased\virtualtree\tvitemdata.h(105) : error C2664: 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,s
truct std::less<long>,class std::allocator<class CTVItemData> >::iterator __thiscall std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::insert(class std::_Tree<long,struct std::pair<long const ,cla
ss CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,class std::allocator<class CTVItemData> >::iterator,const struct std::pair<long const ,class CT
VItemData> &)' : cannot convert parameter 2 from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::le
ss<long>,class std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData> &'
        Reason: cannot convert from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,clas
s std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData>'
        No constructor could take the source type, or constructor overload resolution was ambiguous
TVItemDataMgrFolders.cpp
d:\vc++\dlgbased\virtualtree\tvitemdata.h(105) : error C2664: 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,s
truct std::less<long>,class std::allocator<class CTVItemData> >::iterator __thiscall std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::insert(class std::_Tree<long,struct std::pair<long const ,cla
ss CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,class std::allocator<class CTVItemData> >::iterator,const struct std::pair<long const ,class CT
VItemData> &)' : cannot convert parameter 2 from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::le
ss<long>,class std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData> &'
        Reason: cannot convert from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,clas
s std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData>'
        No constructor could take the source type, or constructor overload resolution was ambiguous
TVItemDataMgrPublic.cpp
d:\vc++\dlgbased\virtualtree\tvitemdata.h(105) : error C2664: 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,s
truct std::less<long>,class std::allocator<class CTVItemData> >::iterator __thiscall std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::insert(class std::_Tree<long,struct std::pair<long const ,cla
ss CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,class std::allocator<class CTVItemData> >::iterator,const struct std::pair<long const ,class CT
VItemData> &)' : cannot convert parameter 2 from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::le
ss<long>,class std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData> &'
        Reason: cannot convert from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,clas
s std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData>'
        No constructor could take the source type, or constructor overload resolution was ambiguous
TVItemDataMgrThreads.cpp
d:\vc++\dlgbased\virtualtree\tvitemdata.h(105) : error C2664: 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,s
truct std::less<long>,class std::allocator<class CTVItemData> >::iterator __thiscall std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::insert(class std::_Tree<long,struct std::pair<long const ,cla
ss CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,class std::allocator<class CTVItemData> >::iterator,const struct std::pair<long const ,class CT
VItemData> &)' : cannot convert parameter 2 from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::le
ss<long>,class std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData> &'
        Reason: cannot convert from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,clas
s std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData>'
        No constructor could take the source type, or constructor overload resolution was ambiguous
TVItemDataMgrTree.cpp
d:\vc++\dlgbased\virtualtree\tvitemdata.h(105) : error C2664: 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,s
truct std::less<long>,class std::allocator<class CTVItemData> >::iterator __thiscall std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::insert(class std::_Tree<long,struct std::pair<long const ,cla
ss CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,class std::allocator<class CTVItemData> >::iterator,const struct std::pair<long const ,class CT
VItemData> &)' : cannot convert parameter 2 from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::le
ss<long>,class std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData> &'
        Reason: cannot convert from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,clas
s std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData>'
        No constructor could take the source type, or constructor overload resolution was ambiguous
VirtualTree.cpp
d:\vc++\dlgbased\virtualtree\tvitemdata.h(105) : error C2664: 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,s
truct std::less<long>,class std::allocator<class CTVItemData> >::iterator __thiscall std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::insert(class std::_Tree<long,struct std::pair<long const ,cla
ss CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,class std::allocator<class CTVItemData> >::iterator,const struct std::pair<long const ,class CT
VItemData> &)' : cannot convert parameter 2 from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::le
ss<long>,class std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData> &'
        Reason: cannot convert from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,clas
s std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData>'
        No constructor could take the source type, or constructor overload resolution was ambiguous
VirtualTreeDlg.cpp
d:\vc++\dlgbased\virtualtree\tvitemdata.h(105) : error C2664: 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,s
truct std::less<long>,class std::allocator<class CTVItemData> >::iterator __thiscall std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::insert(class std::_Tree<long,struct std::pair<long const ,cla
ss CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,class std::allocator<class CTVItemData> >::iterator,const struct std::pair<long const ,class CT
VItemData> &)' : cannot convert parameter 2 from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::le
ss<long>,class std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData> &'
        Reason: cannot convert from 'class std::_Tree<long,struct std::pair<long const ,class CTVItemData>,struct std::multimap<long,class CTVItemData,struct std::less<long>,class std::allocator<class CTVItemData> >::_Kfn,struct std::less<long>,clas
s std::allocator<class CTVItemData> >::iterator' to 'const struct std::pair<long const ,class CTVItemData>'
        No constructor could take the source type, or constructor overload resolution was ambiguous