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[Boost.Test] BOOST_CHECK_THROW behaviour
by Ghyslain Leclerc 23 Jun '14

23 Jun '14

Hello, Sorry for the long post! I have a simple class, which I am posting a fraction of here for discussion sake: ------------------------------------------------------ class AsciiTableRow { public: void setCol( std::size_t colIdx, std::string const& newContent ); void setCol( std::size_t colIdx, const char* newContent ); private: void checkIdxBound_( std::size_t colIdx, std::string const& msg ); std::vector< std::string > data_; bool maxColWidthIsValid_; } inline void AsciiTableRow::setCol( std::size_t colIdx, std::string const& newVal ) { checkIdxBound_( colIdx, "setCol" ); maxColWidthIsValid_ = false; data_[colIdx] = newVal; } inline void AsciiTableRow::setCol( std::size_t colIdx, const char* newContent ) { setCol( colIdx, std::string( newContent ) ); } inline void AsciiTableRow::checkIdxBound_( std::size_t colIdx, std::string const& msg ) { if( colIdx > data_.size() ) { throw std::out_of_range( "AsciiTableRow::" + msg + " : colIdx out of range" ); } } ------------------------------------------------------ The code above should be sufficient for the discussion and I don’t think any other code is relevant. Should you need to see my constructor and destructor, nothing is virtual so I just copy every value and set some defaults. Nothing fancy, but I will gladly post the code if need be. What I do then is try and devise a test to see if the exception is indeed thrown and if it is the correct one. Here is the code I use: AsciiTableRow testRow; // empty, so any index will throw BOOST_CHECK_THROW( testRow.setCol( 30, 12 ), std::out_of_range ); BOOST_CHECK_THROW( testRow.setCol( 30, 12l ), std::out_of_range ); This works fine. Then, I had the idea to check what the behaviour would be if the wrong exception is thrown. I simply changed the first call like this : BOOST_CHECK_THROW( testRow.setCol( 30, 12 ), std::runtime_error ); BOOST_CHECK_THROW( testRow.setCol( 30, 12l ), std::out_of_range ); I was under the impression (and I might be wrong here, sorry :-( ) that the Boost.Test library would (the numbers are not to mean that order, simply there for enumeration): 1- output a message saying the test has failed, that an exception was indeed thrown, but it was not a runtime_error 2- continue the rest of the test (single test currently) 3- terminate but I actually never get the message of step 1, the execution of the rest of the test seems never occur (the second BOOST_CHECK_THROW) and the program terminate because of my exception and not very gracefully. I guess my questions to the other users here are: - Was my understanding of what BOOST_CHECK_THROW does flawed ? - Is the behaviour normal ? - Is there an obvious problem I am missing with the design of my simple class ? In case it is useful, I am on OSX 10.9. I have compiled boost myself (sources of version 1.55 downloaded from the Boost site). I compile my work with C++11 enabled. I am using GCC 4.7 installed via Macports. Anyhow, any insight will be appreciated. As everyone is busy, thanks in advance to anybody for any time spent on this. Ghyslain

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[asio] Closing async client socket after writing last message
by Nicholas Yue 23 Jun '14

23 Jun '14

Hi, I have adapted the chat tutorial example to send messages to a similar (chat tutorial based) server. It is currently working fine however due to the async_write(), I can't close the socket until after all the pending data has been processed on the server end. I have google and found discussion and mentioned about async_write() completion handler calling socket.close() however, I was not able to find specific detail as to how that is done. I want to avoid closing the connection prematurely as it is asynchronous writing. My current do_write() looks like this void DisplayChatClient::do_write(DisplayChatMessage msg) { DLOG(INFO) << "DisplayChatClient::do_write()"; bool write_in_progress = !write_msgs_.empty(); write_msgs_.push_back(msg); if (!write_in_progress) { boost::asio::async_write(socket_, boost::asio::buffer(write_msgs_.front().data(), write_msgs_.front().length()), boost::bind(&DisplayChatClient::handle_write, this, boost::asio::placeholders::error)); } } void DisplayChatClient::handle_write(const boost::system::error_code& error) { DLOG(INFO) << "DisplayChatClient::handle_write()"; if (!error) { write_msgs_.pop_front(); if (!write_msgs_.empty()) { boost::asio::async_write(socket_, boost::asio::buffer(write_msgs_.front().data(), write_msgs_.front().length()), boost::bind(&DisplayChatClient::handle_write, this, boost::asio::placeholders::error)); } } else { do_close(); } } Cheers -- Nicholas Yue Graphics - Arnold, Alembic, RenderMan, OpenGL, HDF5 Custom Dev - C++ porting, OSX, Linux, Windows http://au.linkedin.com/in/nicholasyue https://vimeo.com/channels/naiadtools

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Boost Filesystem fails with FreeBSD 10, clang, and boost
by Ricky Huang 21 Jun '14

21 Jun '14

Hello all, I am currently migrating to a FreeBSD 10 system which comes default with clang language. I was able to compile Boost just fine. But when I include filesysstem.hpp to it, I get the following error message: > Linking CXX executable boost_clang_test > /usr/bin/ld: : invalid DSO for symbol `_ZN5boost6system15system_categoryEv' definition > /usr/local/lib/libboost_system.so.1.55.0: could not read symbols: Bad value > CC: error: linker command failed with exit code 1 (use -v to see invocation) > *** Error code 1 > > Stop. I am using cmake as my build system, could it be possible that I need to adjust my cmake variables? I am not sure if I've came to correct forum or should this be on FreeBSD, clang, CMake forum(s)? Please let me know if I am at the wrong place… The minimum amount of code to induce the problem are the following 2 files: CMakeLists.txt: cmake_minimum_required(VERSION 2.8) # Find and include Boost libraries find_package(Boost 1.55 COMPONENTS filesystem REQUIRED) include_directories(${Boost_INCLUDE_DIR}) set(LIBS ${LIBS} ${Boost_LIBRARIES}) set(BOOST_CLANG_TEST_SOURCES ${SOURCES} main.cpp) add_executable(boost_clang_test ${BOOST_CLANG_TEST_SOURCES}) target_link_libraries(boost_clang_test ${LIBS}) main.cpp: #include <stdio.h> #include <iostream> #include <sstream> #include <string> #include <boost/filesystem.hpp> using namespace std; using namespace boost::filesystem; const char *progname; int main(int argc, char **argv){ return 0; } Thanks in advance.

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[graph] kamada_kawai_spring_layout warnings
by Michael Olea 21 Jun '14

21 Jun '14

Hi. I'm getting compiler warnings for subscripts out of range from kamada_kawai_spring_layout.hpp. I'm using boost_55_0, compiled with clang: Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn) Target: x86_64-apple-darwin13.2.0 Thread model: posix ../../../../../include/boost/graph/kamada_kawai_spring_layout.hpp:110:49: warning: array index 2 is past the end of the array (which contains 2 elements) [-Warray-bounds] double denom = mat[0][0] * (mat[1][1] * mat[2][2] - mat[2][1] * mat[1][2]) The offending code is: template <> struct linear_solver<3> { template <typename Vec> static Vec solve(double mat[2][2], Vec rhs) { double denom = mat[0][0] * (mat[1][1] * mat[2][2] - mat[2][1] * mat[1][2]) - mat[1][0] * (mat[0][1] * mat[2][2] - mat[2][1] * mat[0][2]) + mat[2][0] * (mat[0][1] * mat[1][2] - mat[1][1] * mat[0][2]); double x_num = rhs[0] * (mat[1][1] * mat[2][2] - mat[2][1] * mat[1][2]) - rhs[1] * (mat[0][1] * mat[2][2] - mat[2][1] * mat[0][2]) + rhs[2] * (mat[0][1] * mat[1][2] - mat[1][1] * mat[0][2]); double y_num = mat[0][0] * (rhs[1] * mat[2][2] - rhs[2] * mat[1][2]) - mat[1][0] * (rhs[0] * mat[2][2] - rhs[2] * mat[0][2]) + mat[2][0] * (rhs[0] * mat[1][2] - rhs[1] * mat[0][2]); double z_num = mat[0][0] * (mat[1][1] * rhs[2] - mat[2][1] * rhs[1] ) - mat[1][0] * (mat[0][1] * rhs[2] - mat[2][1] * rhs[0] ) + mat[2][0] * (mat[0][1] * rhs[1] - mat[1][1] * rhs[0] ); Vec result; result[0] = x_num / denom; result[1] = y_num / denom; result[2] = z_num / denom; return result; } }; Looks like it should be: static Vec solve(double mat[3][3], Vec rhs) ... No?

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stack unwinding with boost::fcontext
by David Frank 20 Jun '14

20 Jun '14

Context - 1.53.0 beta1 Context - 1.53.0 beta1 Context Struct fcontext_t and related functions Each instance of fcontext_t represents a context (CPU registers and stack space). View on www.boost.org Preview by Yahoo I'm wondering if there is any example showing how to do stack unwinding as described at the bottom of the above link as quoted below: " Stack unwinding Sometimes it is necessary to unwind the stack of an unfinished context to destroy local stack variables so they can release allocated resources (RAII pattern). The user is responsible for this task. " Thanks, Frank

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[coroutine] await_emu example
by bbxiong 20 Jun '14

20 Jun '14

Hi, coroutine listers! The example is very awesome. but after reading though the source, i have a question: Is any limitation makes a push_coroutine must be caller and pull_coroutine must be the coro? This way, we have to yield out at the first line of coroutine function by calling caller(), just like the example showed: typedef coroutines::pull_coroutine<void> coro_pull; typedef coroutines::pull_coroutine<void> coro_push; auto asynchronous(F f) -> future<decltype(f())> { typedef promise<decltype(f())> CoroPromise; CoroPromise coro_promise; auto coro_future = coro_promise.get_future(); CurrentCoro current_coro = { make_shared<coro_pull>(std::bind([f](CoroPromise &coro_promise, coro_push &caller) { caller(); coro_stack.top().caller = &caller; coro_promise.set_value(f()); }, std::move(coro_promise), placeholders::_1); }; coro_stack.push(std::move(current_coro)); (*coro_stack.top().coro)(); coro_stack.pop(); return coro_future; } There is an extra call to caller() in coroutine function to jump out to prepare coro stack. Why not swap coro_pull and coro_push like this: auto asynchronous(F f) -> future<decltype(f())> { typedef promise<decltype(f())> CoroPromise; CoroPromise coro_promise; auto coro_future = coro_promise.get_future(); CurrentCoro current_coro = { make_shared<coro_push>(std::bind([f](CoroPromise &coro_promise, coro_pull &caller) { coro_stack.top().caller = &caller; coro_promise.set_value(f()); }, std::move(coro_promise), placeholders::_1); }; coro_stack.push(std::move(current_coro)); (*coro_stack.top().coro)(); coro_stack.pop(); return coro_future; } This still works on my machine, and has no extra "call to caller()", push_coroutine is not invoked until we explicitly run it (while pull_coroutine is invoked in constructor). So, my question is, s there any bad effects by using coroutines in this way? Thanks in advance!

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How to use vertex mapping parameter in copy_graph
by Christoph Czurda 19 Jun '14

19 Jun '14

Hello! I want to create a straight line drawing of a planar graph that is not maximal planar. So I want to follow the instructions in http://www.boost.org/doc/libs/1_55_0/libs/graph/doc/straight_line_drawing.h… : "If you want to draw a graph g, you can create a copy g' of g, store a mapping m of vertices in g' to vertices in g, triangulate g', and then send g' in as the input to chrobak_payne_straight_line_drawing. The drawing returned can then be applied to g using m to translate vertices from one graph to another." But I'm stuck at the point where I need to make a copy of the graph and store the vertex-to-vertex mapping between the two graphs. I'm not good enough at C++ to understand from the documentation at http://www.boost.org/doc/libs/1_55_0/libs/graph/doc/copy_graph.html how to provide or access the last parameter orig_to_copy(Orig2CopyMap c) If someone could fill in the missing code in this function, I would be most thankful! void doSomething(MyGraph_t& g){ MyGraph_t g_copy; copy_graph(g, g_copy, [...???...]); // here I would like to access the Orig2CopyMap which stores the mapping }

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Prominent Booster makes a big splash
by Robert Ramey 19 Jun '14

19 Jun '14

Notice that our own Matthias Troyer - important boost contributor made a big splash. http://www.theverge.com/2014/6/19/5824336/google-s-quantum-computer-just-fl… Robert Ramey -- View this message in context: http://boost.2283326.n4.nabble.com/Prominent-Booster-makes-a-big-splash-tp4… Sent from the Boost - Users mailing list archive at Nabble.com.

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[archive] binary archive to memory stream
by Michael Powell 19 Jun '14

19 Jun '14

Hello, I am wrapping my head around archive, specifically binary archive. I'd like to serialize a vector of objects in such a way, I need to capture intermediate vector buffers (literally, to vector of uint8_t) so that I can determine their sizes. After which point the parent object(s) can serialize to file using more conventional, built-in file streams and such. It seems that binary_oarchive is helpful, but still requires there be an ostream or streambuf in the mix. Which, as an adapter layer, while helpful, it still leaves the question of extending streambuf to work with ostream to vector<uint8_t> open. I've read some docs on vectors and streambuf, but they all seem to be geared towards a known-size vector, istream and such. I am interested in a vector that can be streamed to, will grow in size, etc. Some clues seem to hint at underflow, overflow type issues? Any helpful pointers how to go about doing this? Thanks... Best regards, Michael Powell

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[Python]compiling python library
by Miklós Tóth 19 Jun '14

19 Jun '14

Hi All, I want to embed python in my c++ code using boost.python library. As far as I understand I need python headers and libs. So my python27.lib is "incompatible". I want to compile it from code but I failed with mingw32. Could you give me some advice, or links to achieve my goal? I'm using gcc4.6.3 and qt 4.8.2 and boost 1.49 on windows 7. Thanks, Miklós

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