I'm new to boost. It seems that the coding of boost library is not very clean as it makes the debug code aborted by generating a runtime error like this: "error: attempt to copy-construct an iterator from a singular iterator.".

Here are the steps to reproduce the fault:

I downloaded the source and install the things to /usr/local/include as well as /usr/local/lib.

I test the code by creating a "C++ Tool" project in XCode.

1. Create a new C++ Tool project.

2. Add the header search path /usr/local/include/boost-1_39 and library search path /usr/local/lib into the project.

3. Add "Other Linker Flags" "-lboost_system-xgcc40-mt" in the project setting.

4. Edit the main.cpp as below:

#include <iostream>

#include<boost/asio.hpp>

int main (int argc, char * const argv[])

{

boost::asio::io_service io_service;

boost::asio::ip::tcp::acceptor acceptor(io_service);

std::cout<<"acceptor instantiated."<<std::endl;

return 0;

}

5. Build and run. Check out the result from the Console window as captured below:

[Session started at 2009-07-28 16:00:10 +0800.]

/Developer/SDKs/MacOSX10.5.sdk/usr/include/c++/4.0.0/debug/safe_iterator.h:127:

error: attempt to copy-construct an iterator from a singular iterator.

Objects involved in the operation:

iterator "this" @ 0x0x100480 {

type = N11__gnu_debug14_Safe_iteratorIN10__gnu_norm14_List_iteratorISt4pairIiPN5boost4asio6detail16reactor_op_queueIiE7op_baseEEEEN15__gnu_debug_def4listISB_SaISB_EEEEE (mutable iterator);

state = singular;

}

iterator "other" @ 0x0xbffff364 {

type = N11__gnu_debug14_Safe_iteratorIN10__gnu_norm14_List_iteratorISt4pairIiPN5boost4asio6detail16reactor_op_queueIiE7op_baseEEEEN15__gnu_debug_def4listISB_SaISB_EEEEE (mutable iterator);

state = singular;

}

[Session started at 2009-07-28 16:00:10 +0800.]

GNU gdb 6.3.50-20050815 (Apple version gdb-966) (Tue Mar 10 02:43:13 UTC 2009)

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It generates a runtime error "error: attempt to copy-construct an iterator from a singular iterator.".

However, if I compile the code in terminal:

g++ -o test -g -Wall main.cpp -lboost_system-xgcc40-mt

It runs okay without any runtime error.

Regards,

Victor Tsang