Is it possible to create a cross-platform desktop application in Visual Studio 2017 that will run in both Windows 10 and Linux environments (how is it done)?  
I don't see any "New Project" options that stand out, nor much information on the web.

Thanks

I have following version of eclipse IDE installed in my computer:
Eclipse IDE for C/C++ Developers
Version: 2018-09 (4.9.0)

I created a workspace.  There are number of Templates for New C / C++ Project.
I need to import very large 'C' source code files into my project.  I won't be compiling code in eclipse.  I'll just be navigating source code.
Which Project template should I select?  Is there a way to create project without selecting a project template?

Hey!

I am developing an application using JetBrains CLion 2018.2.4 with cmake 3.12.2 and Visual Studio 2017 compiler.
Let me set up things first.

Here is the base class:

class Header
{
public:
   enum MessageType
   {
      Message = 100,
      Command = 101,
      InvalidMessage = 102
   };

   Header();
   Header(Header::MessageType messageType);
   virtual ~Header() = default;

   Header::MessageType GetMessageType() const;
private:
   Header::MessageType m_messageType;
};

Header::Header() :
   m_messageType(Header::MessageType::InvalidMessage)
{
}

Header::Header(Header::MessageType messageType) :
   m_messageType(messageType)
{
}

Header::MessageType Header::GetMessageType() const
{
   return m_messageType;
}

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Here is the derived class:

class Message : public Header
{
public:
   Message();
   ~Message() = default;

   void SetMessage(std::string message);
   std::string GetMessage() const&;

private:
   std::string m_message;
};

Message::Message() :
   Header(Header::MessageType::Message),
   m_message("")
{
}

void Message::SetMessage(std::string message)
{
   m_message = message;
}

std::string Message::GetMessage() const&
{
   return m_message;
}

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Here is how I'm acessing the function GetMessage();

int main()
{
   Reader reader;

   auto basePtr = reader.ReadAll(message);
   auto derivedPtr = std::dynamic_pointer_cast<communication::Message>(basePtr);
   std::cout << "read: " << derivedPtr->GetMessageType() << ";" << derivedPtr->GetMessage();
}

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When I try to execute GetMessage() like up above, I get the error below:

Server.cpp.obj : error LNK2019: unresolved external symbol "public: class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __thiscall communication::Message::GetMessageA(void)const & " (?GetMessageA@Message@communication@@QGBE?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@XZ) referenced in function _main
Server.exe : fatal error LNK1120: 1 unresolved externals

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It has to do with the function GetMessage() but I'm failing to see what is wrong. If I remove that call, everything compile fine.
Also, I do the exact same call in other class and it is working fine.
Help is needed!!!

I'm trying to understand the structure of the open file table. During this search I'm reading things that look like (for me) they are in contrast with each other.

In a system there is a:

File descriptor table:
This table is located in user space and is associated with a certain process (per-process).

Open file table:
This table is located in kernel space and is associated with all processes (process-wide).

Entries in the file descriptor table point to the open file table. This all is clear. Now let's go to the structure of these tables. For example, see: https://elixir.bootlin.com/linux/v3.18/source/include/linux/fdtable.h#L24

struct fdtable {
        [...]
};

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And:

/*
 * Open file table structure
 */
struct files_struct {
        [...]
};

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Also this is clear. But now see for example: http://www.andrew.cmu.edu/user/gkesden/ucsd/classes/sp17/cse291-a/applications/ln/lecture5.html

Per Process File Information

struct files_struct { /* kept within task_struct (PCB) */
        [...]
};

Here they are talking about files_struct when it's about "per process file information". I don't understand this, because the open file table is process-wide. This is for example what they are saying:

The count variable tracks the number of files the process has open

But imagine ... two different processes point to the same entry in the open file table. I think …

Question is related to C++ STL list::sort(Compare) where Compare is now a template.

I am looking for the correct syntax to override the list::sort(Compare) definition to work with list<pair<int, T> > definition.

//-The Compare Function

template<typename W>
bool weightsort(const pair<int, W> &node1, const pair<int, W> &node2)
{
    return (node1.second <= node2.second);
}


//- Abbreviated class definition containing  STL list definition and call to sort

template<typename T>
class Graph {
    ...
    vector<T> shortest_reach(int startId, T sigWeight) {
        ...
        list<pair<int, T> >                                       frontier;   //-Nodes currently on the Queue to be Explored.
        typename list<pair<int, T> >::iterator      fit;
        ...
            frontier.sort(weightsort);
        ...
    }
    ....
};


$ c++ program.cpp

error: no matching member function for call to 'sort'
            frontier.sort(weightsort);
            ~~~~~~~~~^~~~

usr/include/c++/v1/list:1059:14: note: candidate template ignored:
      couldn't infer template argument '_Comp'
        void sort(_Comp __comp);
             ^
/usr/include/c++/v1/list:1056:10: note: candidate function not viable:
      requires 0 arguments, but 1 was provided
    void sort();
         ^

I want to create a server(OS: CentOS) which will be acting as an interface to an Android app(client) and the database.

I am not much experienced in programming and I just want a little bit of guidance right now to get started.
I have decided that I want to program the server in C++(though it's not an easy language but I believe there's much more to learn while programming in C++)

The basic functionality I want from my server:
1. It will interact with the app via https.
2. The server and client(app) will communicate via REST APIs.

I want guidance in terms of the most stable and well documented external C++ libraries that I should use to program the above server(I've looked at zmq, libcurl, netlib-cpp but due to my lack of experience I don't even know if these are really related to my problem statement). Thanks in advance. Please feel free to attach any blog/article/video which might be relevant.

I have an issue using an ADOQuery component with C++ builder.
If I execute a simple query "select * from Frames where FrameID = 1934411" the result is no record returned when Frames is a view.
However, if I copy the entire view contents into a table and then run the query against the table then the Record is found ?
The database is a Microsoft SQL Server version 12.0.5207.0

If I run the query on the view or the table using Microsoft SQL Server Management Studio then in both cases the record is returned.

Can this be fixed to use the view ?

Hello , i've the following routine :

int Asio_Send_Pck(int iSendt,int Lsocket,char * Lbuff,int Len)

{

    LSession* iTempLSession = reinterpret_cast<LSession*>(Lsocket);

    boost::asio::async_write(iTempLSession->socket() ,

                              boost::asio::buffer(Lbuff, Len),

                              boost::bind(&LSession::handle_write, 

                              iTempLSession,

                              boost::asio::placeholders::error,

                              iTempLSession->data,

                              iSendt

                              ));

    return 0;

};

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But i always get an Invalid Arguments .

Here's my Lsession class :

class LSession
{
public:
  int readlen;
  int userdata;
  int deadtime;
  enum { max_length = 1024};
  char data_[max_length];
  
   LSession(boost::asio::io_service& io_service)
        : deadtime(0), socket_(io_service)
    {
        readlen = 0;
        userdata = 0;
    }

  ~LSession()
  {
	  socket_.close();
  }

  tcp::socket& socket()
  {
    return socket_;
  }

  void start()
  {	  
    socket_.async_read_some(boost::asio::buffer(data_, max_length),
        boost::bind(&LSession::handle_read, this,
          boost::asio::placeholders::error,
          boost::asio::placeholders::bytes_transferred));
  }

  void handle_read(const boost::system::error_code& error,
      size_t bytes_transferred)
  { 
    if (!error)
    {
	
	  try
	  {
	  if(Callback_readdata!= NULL)
	  

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…

I have a problem whit the LRESULT CALLBACK WndProc,
When i add LPARAM wp the wc give's me a error message, for get the callback functionality when selecting a drop menu item.



main.cpp: In function 'int WinMain(HINSTANCE, HINSTANCE, LPSTR, int)':
main.cpp:56:24: error: invalid conversion from 'LRESULT (__attribute__((__stdcall__)) *)(HWND, UINT, WPARAM, LPARAM, LPARAM) {aka long int (__attribute__((__stdcall__)) *)(HWND__*, unsigned int, unsigned int, long int, long int)}' to 'WNDPROC {aka long int (__attribute__((__stdcall__)) *)(HWND__*, unsigned int, unsigned int, long int)}' [-fpermissive]
     wc.lpfnWndProc   = WndProc;

#include <windows.h>

void AddMenus(HWND);
HMENU hMenu;

int ID_Save;
int wp;

const char g_szClassName[] = "myWindowClass";

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam, LPARAM wp)
{
    
    
    switch(msg)
    {
        case WM_COMMAND:
        
        switch(wp)

        {
            case 1:
            MessageBeep(MB_OK);
            break;

        }


        case WM_ACTIVATE:
            AddMenus(hwnd);
            break;
        case WM_CLOSE:
            DestroyWindow(hwnd);
        break;
        case WM_DESTROY:
            PostQuitMessage(0);
        break;
        default:
        return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    
return 0;
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,  LPSTR lpCmdLine, int nCmdShow)
{
    WNDCLASSEX wc;
    HWND hwnd;
    

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…

C++ add menu,
it seems ther is no problem but when the window is created the menu don't show on the screen.
do i need to add a redraw option ?

When i go the a other active window the menu is created. strains.

#include <windows.h>

void AddMenus(HWND);
HMENU hMenu;

int ID_Save;


const char g_szClassName[] = "myWindowClass";

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    {
        
        case WM_CREATE:
            AddMenus(hwnd);
            break;
        case WM_CLOSE:
            DestroyWindow(hwnd);
        break;
        case WM_DESTROY:
            PostQuitMessage(0);
        break;
        default:
        return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    
    
    return 0;
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,  LPSTR lpCmdLine, int nCmdShow)
{
    WNDCLASSEX wc;
    HWND hwnd;
    MSG Msg;
   
    wc.cbSize        = sizeof(WNDCLASSEX);
    wc.style         = 0;
    wc.lpfnWndProc   = WndProc;
    wc.cbClsExtra    = 0;
    wc.cbWndExtra    = 0;
    wc.hInstance     = hInstance;
    wc.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
    wc.lpszMenuName  = NULL;
    wc.lpszClassName = g_szClassName;
    wc.hIconSm       = LoadIcon(NULL, IDI_APPLICATION);

    
    if(!RegisterClassEx(&wc))
    {
        MessageBox(NULL, "Window Registration Failed!", 

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…