// convert_from_bstr_t.cpp
// compile with /clr /link comsuppw.lib

#include <iostream>
#include <stdlib.h>
#include <string>

#include "atlbase.h"
#include "atlstr.h"
#include "comutil.h"

using namespace std;
using namespace System;

//===========================================================================
int main()
//===========================================================================
{

 _bstr_t   orig("Hello, World!");
 wcout << orig << " (_bstr_t)" << endl;

 // Convert to a char*
 const size_t newsize = 100;
 char   nstring[newsize];
 strcpy_s(nstring, (char *)orig);
 strcat_s(nstring, " (char *)");
 cout << nstring << endl;

 // Convert to a wchar_t*
 wchar_t   wcstring[newsize];
 wcscpy_s(wcstring, (wchar_t *)orig);
 wcscat_s(wcstring, L" (wchar_t *)");
 wcout << wcstring << endl;

 // Convert to a CComBSTR
 CComBSTR  ccombstr((char *)orig);
 if (ccombstr.Append(L" (CComBSTR)") == S_OK)
 {
  CW2A  printstr(ccombstr);
  cout << printstr << endl;
 }

 // Convert to a CString
 CString   cstring((char *)orig);
 cstring += " (CString)";
 cout << cstring << endl;

 // Convert to a basic_string
 string   basicstring((char *)orig);
 basicstring += " (basic_string)";
 cout << basicstring << endl;

 // Convert to a System::String
 String ^systemstring = gcnew String((char *)orig);
 systemstring += " (System::String)";
 Console::WriteLine("{0}", systemstring);
 delete systemstring;
}

출력
Hello, World! (_bstr_t)
Hello, World! (char *)
Hello, World! (wchar_t *)
Hello, World! (CComBSTR)
Hello, World! (CString)
Hello, World! (basic_string)
Hello, World! (System::String)