Recent changes to support-requests

Boost Asio Compilation issue on RAD Studio XE5.

Nilesh — Fri, 30 May 2014 12:15:21 -0000

Hi,

I want to use SSL in my project which is using RAD Studio XE5(Borland C++ Builder). I want to use SSL TCP socket in my existing project which is currently running on plain socket. As Boost is header only lib, I have added following path in include directories list. Already compiled and installed OpenSSL at C:\OpenSSL folder using Visual C++.

C:\Program Files (x86)\Embarcadero\RAD Studio\12.0\include\boost_1_50

Added following include paths in my code file. No new code added, only include headers.

include "boost/bind.hpp"
include "boost/asio.hpp"
include "boost/asio/ssl.hpp"

When I compiled my code in RAD Studio(Borland C++ builder), I received following errors.

[bcc32 Error] buffer.hpp(1788): E2335 Overloaded 'unsigned int buffer_copy(const mutable_buffers_1 &,const mutable_buffers_1 &)' ambiguous in this context

[bcc32 Error] socket_ops.ipp(1725): E2034 Cannot convert 'system::error_code' to 'error::basic_errors'

[bcc32 Error] not.hpp(28): E2396 Template argument must be a constant expression

[bcc32 Error] not.hpp(28): E2402 Illegal base class type: formal type 'bool_<(bool)(C_==0)>' resolves to 'bool_<(bool)(C_==0)>'

Do you have any idea why these errors are coming. As I haven't added any code in my project. Just header files included. Is there any conditional defines I have to specify?

Thanks & Regards
Nilesh

Documentation error: async_write() "always returns immediately" [false?]

sfuser3 — Thu, 03 Apr 2014 19:37:37 -0000

The program shown below was compiled using GNU g++ v4.4.3:

$ g++ -o main main.cc -lboost_system  # Boost 1-55-0

The program prints the string
@The quick brown fox jumps over the lazy dog.
one character at a time and, in doing so, it clearly demonstrates that both:

a call to the CompletionCheck functor occurs, and
the output of the first character [i.e. @] occurs

before the call to async_write() returns. The evidence can be found on the 1st and 2nd lines of the program's output:

$ ./main
 - CompletionCheck::operator()(error=system:0, bytes transferred=0)
@ - async_write() has returned
The quick brown fox jumps over the lazy dog.
handler() - completion handler called

which shows:

1st line: The functor output [e.g. "bytes_transferred=0"]
2nd line: The string's first character, the "@" symbol, followed by
2nd line: The text: " - async_write() has returned".

The rest of the string is printed only after invoking the io_service's run() method.

So: Is the async_write() documentation incorrect when it states that the call "always returns immediately" ?

I would have expected nothing to happen until calling the run() method.

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <vector>
#include <iostream>
#include <boost/asio.hpp>
#include <boost/bind.hpp>

static void handler(const boost::system::error_code& error, std::size_t bytes_transferred)
{
    std::cerr << "handler() - completion handler called" << std::endl;
}

class CompletionCheck
{
public:
    CompletionCheck(std::vector<boost::asio::const_buffer>& buffers)
    :   count_(boost::asio::buffer_size(buffers))
    {
    }

    size_t operator()(const boost::system::error_code& error, std::size_t bytes_transferred)
    {
        if (bytes_transferred == 0)
        {
            std::cerr << " - CompletionCheck::operator()(error=" << error
                      << ", bytes transferred=" << bytes_transferred << ")" << std::endl;
        }

        if (count_)
        {
            --count_;
            return 1;
        }
        return 0;
    }

private:
    size_t  count_;
};

int main(int argc, char * argv[])
{
    boost::asio::io_service iosvc;

    std::vector<boost::asio::const_buffer> vec;
    vec.push_back(boost::asio::buffer("@The"));
    vec.push_back(boost::asio::buffer(" quick"));
    vec.push_back(boost::asio::buffer(" brown"));
    vec.push_back(boost::asio::buffer(" fox"));
    vec.push_back(boost::asio::buffer(" jumps"));
    vec.push_back(boost::asio::buffer(" over"));
    vec.push_back(boost::asio::buffer(" the"));
    vec.push_back(boost::asio::buffer(" lazy"));
    vec.push_back(boost::asio::buffer(" dog.\n"));

    boost::asio::posix::stream_descriptor ios(iosvc);
    ios.assign(::open("/dev/tty", O_WRONLY|O_ASYNC));
    CompletionCheck check(vec);

    boost::asio::async_write(ios, vec, check, boost::bind(&handler, _1, _2));
    std::cerr << " - async_write() has returned" << std::endl;

    iosvc.run();

    return 0;
}

Find local IP address

Anonymous — Tue, 19 Feb 2008 01:44:52 -0000

How do you find your own IP address using Asio?

Find local IP address

Anonymous — Tue, 19 Feb 2008 01:24:01 -0000

How do you find your own IP address using Asio?

boost::system lib ?

mamelouk — Thu, 19 Apr 2007 14:56:32 -0000

Hi,

I'm trying to compile the client tutorial example, and I get one error at link time.

I didn't found any info about it on the web, it's undefined reference to boost::system::error_code::(a lot of functions).

Do you know which lib I need to link to ?
I'm working under linux ubuntu

Cheers