void Foo(CDataExchange* pDX, int ID, TCHAR string[MAX_PATH])
{
    CString cstr(string);
    DDX_Text(pDX, ID, cstr);
    _tcscpy(string, cstr.GetString());
}

void Foo(CDataExchange* pDX, int ID, TCHAR string[MAX_PATH])
{
    CString cstr(string);
    DDX_Text(pDX, ID, cstr);
    if (MAX_PATH > (cstr.GetLength() + 1))
    {
        _tcscpy_s(string, cstr.GetLength() + 1, cstr.GetString());
    }
}