I have ported some code from an old application that I wrote years ago to receive IP4 multicast data on a local area network using Indy 9.

The same code using Indy 10 on C++ builder XE10.1 Berlin doesn't work. No data is received in the OnIPMCastRead event handler (the event handler isn't triggered).
I have confirmed with wireshark that the network traffic is there on 244.0.0.166 port 60 as per the attached wireshark trace.
My code is as follows and the configuration of the Indy 10 IdIPMCastClient component is shown in the attached image file.
Can anyone explain why it isn't working please ?

#ifndef Unit1H
#define Unit1H
//---------------------------------------------------------------------------
#include <System.Classes.hpp>
#include <Vcl.Controls.hpp>
#include <Vcl.StdCtrls.hpp>
#include <Vcl.Forms.hpp>
#include <IdBaseComponent.hpp>
#include <IdComponent.hpp>
#include <IdGlobal.hpp>
#include <IdIPMCastBase.hpp>[embed=file 1332006][embed=file 1332007]
#include <IdIPMCastClient.hpp>
#include <IdSocketHandle.hpp>
#include <IdUDPBase.hpp>
#include <IdUDPServer.hpp>
//---------------------------------------------------------------------------
class TForm1 : public TForm
{
__published:	// IDE-managed Components
	TIdIPMCastClient *IdIPMCastClient1;
	TButton *Button1;
	void __fastcall IdIPMCastClient1IPMCastRead(TObject *Sender, const TIdBytes AData,
          TIdSocketHandle *ABinding);
	void __fastcall Button1Click(TObject *Sender);
private:	// User declarations

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…

I need some assistance in writing a TCP Server in Embarcadero C++ builder XE 10.1 using  an Indy 10 TCP server VCL control.
How do I accept a connection from a client when using an Indy 10 VCL control TIdTCPServer ?
I imagine that I need to write some code in the OnConnect Event handler although logically one might expect a "BeforeConnect"  event handler .I haven't found any methods anywhere in the AContext or its members called Accept() ?
Also, my understanding is that  when a connection is established, the Execute event is invoked which supplies an AContext parameter which equates to a thread. Can I let the Execute event handler terminate and have a separate thread that manipulates the saved value of the AContext parameter in a list. the separate thread would poll round each AContext in the list  to independently send/receive data to/from the remote clients ?

how to get the SwapTotal for solaris in C or C++?

Hello

I run into this problem with C++ code when on WIndows only.
Severity      Code      Description      Project      File      Line      Source      Suppression State
Error      C2664      'DWORD GetFileAttributesW(LPCWSTR)': cannot convert argument 1 from 'const char *' to 'LPCWSTR'      

This is when reading a string path , converting to char and calling the GetFileAttributes function. I am on windows 10 and compiling for a 32 bit arch (x86)
myfunc(const std::string & path){
DWORD  fileAttr=
GetFileAttributes(path.c_str()); //error list above!
}

Is there a elegant way to handle this? I donot want to be caught up in too much windows specific tailoring too much since my code is supposed to cross compile and run on linux and osx.

I understand the general problem = it is looking for a LPCWSTR long ptr to a 2 byte char. But how can i get it to work inside a #ifdef _WIN32 tag ,so that it stops complaining?

I have the following variadic macro code in a file named main.cc

#define DEBUG_PRINTF(fmt, ...) \
    do { if (verbose_flag) {\
        time_t t;\
        struct tm *t_info;\
        char buff[80];\
        time(&t);\
        t_info = localtime(&t);\
        strftime(buff, sizeof(buff), "%I:%M:%S", t_info);\
        std::string str(buff);\
        std::cout << str << " S" << my_server_instance << " ";\
        printf(fmt,__VA_ARGS__);}} while (0)

when I use g++ version 2.95.3-5 in CYGWIN like g++ -std=c++11 main.cc -c -o main.o to compile it, I get the compile error badly punctuated parameter list in #define and the error line is at printf(fmt,__VA_ARGS__);}} while (0). I have tried to fix it but I have not succeeded. How can this problem be fixed. I would like your directions on this.

pc to usb development, using c++ as the back ground code. i  am just starting so i need to be pointed towards a good cheapish usb development board, not sure what software and how this operates,
also some good reading materials, have down loaded a few books on the subject but not sure were to start.
at the moment all i need to do is to send some code to a board and turn some leds on and off just to get the code started
any help would be appreciated

Using C++11:

I am trying to determine how to handle domain and range errors using the g++ compiler (Mingw64). I have provided some sample code below which is the approach that I use for g++ on Linux systems. When I compile I get the following messages:

warning: ignoring #pragma STDC FENV_ACCESS [-Wunknown-pragmas] #pragma STDC FENV_ACCESS ON
error: 'math_errhandling' was not declared in this scope
error: 'MATH_ERRNO' was not declared in this scope
error: 'MATH_ERREXCEPT' was not declared in this scope

I have looked for these symbols in the normal include headers but I don't see them.  Any help is greatly appreciated. I must note that  math_errhandling, MATH_ERRNO,  MATH_ERREXCEPT and the pragma  STDC FENV_ACCESS are part of the c++(2011) standard.

#include <cmath>
#include <fenv>
#include <cerrno>


#pragma STDC FENV_ACCESS ON
if (math_errhandling & MATH_ERREXCEPT) {
feclearexcept(FE_ALL_EXCEPT);
}
errno = 0;
result = pow(x, y);

if ((math_errhandling & MATH_ERRNO) && errno != 0) {
  /* Handle range error */
}
else if ((math_errhandling & MATH_ERREXCEPT) &&
           fetestexcept(FE_INVALID | FE_DIVBYZERO |
                        FE_OVERFLOW | FE_UNDERFLOW) != 0) {
  /* Handle range error */
}
}
/ Use result... /
}

Hi,
Is there a C/C++ equivalent function for rounding half-even? I need identical function to Java's BigDecimal.setScale(int scale, BigDecimal.ROUND_HALF_EVEN);
So 20.225 = 20.22
20.235 = 20.24
Thanks.

Hi I am seeing "address 0x1 out of bounds segmentation fault" while  accessing the iterater address
typedef eastl::map< EA::TDF::TdfString, eastl::vector<Blaze::Stats::StatDescSummary*> > StatsListByCategoryMap;
```StatsListByCategoryMap::const_iterator itr = mStatsListByCategoryMap.begin();
    for (; itr != mStatsListByCategoryMap.end(); itr++)
    {
        eastl::vector<StatDescSummary*>::const_iterator itrStatDesc = itr->second.begin();
        for (; itrStatDesc != itr->second.end(); itrStatDesc++)
        {

            if ((*itrStatDesc) && (*itrStatDesc)->getName())
            {
                                          statsMap[(*itrStatDesc)->getName()] = getRandomVal(100);
            }```

Acessing value *itrStatDesc->getName()

I have to modify a Qt Creator project on Windows 7. The compiler/linker uses Visual Studio 2010 Pro SP1. (The debugger works on VS, but not on Qt.)
I debug by adding print statements. I want to be able to debug using a debugger.

I found this page which also leads to subsequent links.
http://doc.qt.io/qtcreator/creator-debugger-engines.html

The IT department (one person) is overworked, and this debugger task is considered low priority. Furthermore, the admin has no idea how to get the debugger to work. The lead said that if I can come up with a step-by-step written list of things to do, then he would raise the priority of getting the debugger to work. Statements like "add <...> to Qt screen <...>" doesn't help since IT won't know what to do. Need detailed steps.

Maybe someone has already done this and can provide these detailed steps (supported by links so I can review and ask questions, to help clarify the steps - I get one shot to get this to work). General comments and links without the detailed steps probably won't help the IT guy.

A year ago, I think I saw that we needed a version of SDK (maybe SDK 7.1?) to get the Qt Debugger to work. This SDK is not installed on my Windows 7 workstation, but I am told that we are allowed to install it. In general, we have a list of items we are allowed to install, and anything not on the list is not permitted.

My environment:
Windows 7
Qt Creator 2.6.0 based on Qt 4.8.2
Qt Compiler/linker used is hooked to Visual …

If I start a task with a cancellation token, and I later set the cancellation token to "Cancel", can I then immediately dispose of the cancellation token, or do I need to wait for the task to get the "Cancel" message first?

It's appearing as if I don't need to wait for the task to get the "Cancel" message. It seems to get it anyway:

CancellationTokenSource cts = new CancellationTokenSource();
CancellationToken token = cts.Token;
mytask = Task.Run(async () => await MyEndlessTaskLoop(token), token);

...
// Then later in a button click event:
cts.Cancel();
cts.Dispose();

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Do I need to insert a wait between the "Cancel()" and "Dispose()"?

cts.Cancel();

try {
    mytask.Wait();
}
catch (AggregateException e) {
   // Expect e.InnerException to be "OperationCanceledException"
}

cts.Dispose();

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Also do I need to insert an await in front of Task.Run(...)?

mytask = await Task.Run(async () => await MyEndlessTaskLoop(token), token);

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And, is there a difference between passing the cancellation token as a parameter as opposed to just using it as a captured variable? As in:

private async Task MyEndlessTaskLoop()
{
    while(True)
    {
        ...
        this.token.ThrowIfCancellationRequested;
    }
}

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vs.:

private async Task MyEndlessTaskLoop(CancellationToken token)
{
    while(True)
    {
        ...
        token.ThrowIfCancellationRequested;
    }
}

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Is one preferred over the other?

I have been using VS 2008, and have installed VS 2015 side by side on the same computer. I have projects compiled in VS 20015 from another computer that compile just fine. But when I open those projects and try to compile them in the new VS 2015 on this computer they will not compile. In fact, even creating the simplest "Hello world" application will not compile.

I get errors on standard VS header files. For example, it throws errors and warnings on Windows.h like:

Warning      C4067      unexpected tokens following preprocessor directive - expected a newline      windows.h            

Error      C2061      syntax error: identifier 'LPCSTR'      
Error      C2061      syntax error: identifier 'BYTE'      

I can't figure out why this is happening. Anyone have an idea?

I am a newbie in the data structure, I have read the implementation of stack using a simple array, the algorithm for this implementation is below:-

 Stack Operations using Array

A stack can be implemented using array as follows...

Before implementing actual operations, first follow the below steps to create an empty stack.

Step 1: Include all the header files which are used in the program and define a constant 'SIZE' with specific value.

Step 2: Declare all the functions used in stack implementation.

Step 3: Create a one dimensional array with fixed size (int stack[SIZE])

Step 4: Define a integer variable 'top' and initialize with '-1'. (int top = -1)

Step 5: In main method display menu with list of operations and make suitable function calls to perform operation selected by the user on the stack.

push(value) - Inserting value into the stack

In a stack, push() is a function used to insert an element into the stack. In a stack, the new element is always inserted at top position. Push function takes one integer value as parameter and inserts that value into the stack. We can use the following steps to push an element on to the stack...

Step 1: Check whether stack is FULL. (top == SIZE-1)

Step 2: If it is FULL, then display "Stack is FULL!!! Insertion is not possible!!!" and terminate the function.

Step 3: If it is NOT FULL, then increment top value by one (top++) and set stack[top] to value (stack[top] = value).

pop() -…