Boost Program Options link error - c++

I am having trouble with linking -lboost_program_options. I cannot even compile the minimum example first.cpp.
Here is the cpp:
// Copyright Vladimir Prus 2002-2004.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)
/* The simplest usage of the library.
*/
#include <boost/program_options.hpp>
namespace po = boost::program_options;
#include <iostream>
#include <iterator>
using namespace std;
int main(int ac, char* av[])
{
try {
po::options_description desc("Allowed options");
desc.add_options()
("help", "produce help message")
("compression", po::value<double>(), "set compression level")
;
po::variables_map vm;
po::store(po::parse_command_line(ac, av, desc), vm);
po::notify(vm);
if (vm.count("help")) {
cout << desc << "\n";
return 0;
}
if (vm.count("compression")) {
cout << "Compression level was set to "
<< vm["compression"].as<double>() << ".\n";
} else {
cout << "Compression level was not set.\n";
}
}
catch(exception& e) {
cerr << "error: " << e.what() << "\n";
return 1;
}
catch(...) {
cerr << "Exception of unknown type!\n";
}
return 0;
}
Here is my output:
g++ -o first first.cpp -lboost_program_options
/tmp/ccNDtU66.o: In function `main':
first.cpp:(.text+0x6f): undefined reference to `boost::program_options::options_description::options_description(std::string const&, unsigned int, unsigned int)'
/tmp/ccNDtU66.o: In function `boost::program_options::validation_error::validation_error(boost::program_options::validation_error::kind_t, std::string const&, std::string const&, int)':
first.cpp:(.text._ZN5boost15program_options16validation_errorC2ENS1_6kind_tERKSsS4_i[_ZN5boost15program_options16validation_errorC5ENS1_6kind_tERKSsS4_i]+0x2e): undefined reference to `boost::program_options::validation_error::get_template(boost::program_options::validation_error::kind_t)'
first.cpp:(.text._ZN5boost15program_options16validation_errorC2ENS1_6kind_tERKSsS4_i[_ZN5boost15program_options16validation_errorC5ENS1_6kind_tERKSsS4_i]+0x4c): undefined reference to `boost::program_options::error_with_option_name::error_with_option_name(std::string const&, std::string const&, std::string const&, int)'
/tmp/ccNDtU66.o: In function `boost::program_options::variables_map::operator[](std::string const&) const':
first.cpp:(.text._ZNK5boost15program_options13variables_mapixERKSs[_ZNK5boost15program_options13variables_mapixERKSs]+0x1f): undefined reference to `boost::program_options::abstract_variables_map::operator[](std::string const&) const'
/tmp/ccNDtU66.o: In function `boost::program_options::basic_command_line_parser<char>::basic_command_line_parser(int, char const* const*)':
first.cpp:(.text._ZN5boost15program_options25basic_command_line_parserIcEC2EiPKPKc[_ZN5boost15program_options25basic_command_line_parserIcEC5EiPKPKc]+0x76): undefined reference to `boost::program_options::detail::cmdline::cmdline(std::vector<std::string, std::allocator<std::string> > const&)'
/tmp/ccNDtU66.o: In function `boost::program_options::basic_command_line_parser<char>::extra_parser(boost::function1<std::pair<std::string, std::string>, std::string const&>)':
first.cpp:(.text._ZN5boost15program_options25basic_command_line_parserIcE12extra_parserENS_9function1ISt4pairISsSsERKSsEE[_ZN5boost15program_options25basic_command_line_parserIcE12extra_parserENS_9function1ISt4pairISsSsERKSsEE]+0x33): undefined reference to `boost::program_options::detail::cmdline::set_additional_parser(boost::function1<std::pair<std::string, std::string>, std::string const&>)'
/tmp/ccNDtU66.o: In function `std::vector<std::string, std::allocator<std::string> > boost::program_options::to_internal<std::string>(std::vector<std::string, std::allocator<std::string> > const&)':
first.cpp:(.text._ZN5boost15program_options11to_internalISsEESt6vectorISsSaISsEERKS2_IT_SaIS5_EE[_ZN5boost15program_options11to_internalISsEESt6vectorISsSaISsEERKS2_IT_SaIS5_EE]+0x46): undefined reference to `boost::program_options::to_internal(std::string const&)'
/tmp/ccNDtU66.o:(.rodata._ZTVN5boost15program_options11typed_valueIdcEE[_ZTVN5boost15program_options11typed_valueIdcEE]+0x38): undefined reference to `boost::program_options::value_semantic_codecvt_helper<char>::parse(boost::any&, std::vector<std::string, std::allocator<std::string> > const&, bool) const'
/tmp/ccNDtU66.o:(.rodata._ZTVN5boost15program_options20invalid_option_valueE[_ZTVN5boost15program_options20invalid_option_valueE]+0x30): undefined reference to `boost::program_options::error_with_option_name::substitute_placeholders(std::string const&) const'
/tmp/ccNDtU66.o:(.rodata._ZTVN5boost15program_options16validation_errorE[_ZTVN5boost15program_options16validation_errorE]+0x30): undefined reference to `boost::program_options::error_with_option_name::substitute_placeholders(std::string const&) const'
/tmp/ccNDtU66.o: In function `boost::program_options::typed_value<double, char>::name() const':
first.cpp:(.text._ZNK5boost15program_options11typed_valueIdcE4nameEv[_ZNK5boost15program_options11typed_valueIdcE4nameEv]+0x26): undefined reference to `boost::program_options::arg'
/tmp/ccNDtU66.o: In function `void boost::program_options::validate<double, char>(boost::any&, std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&, double*, long)':
first.cpp:(.text._ZN5boost15program_options8validateIdcEEvRNS_3anyERKSt6vectorISbIT0_St11char_traitsIS5_ESaIS5_EESaIS9_EEPT_l[_ZN5boost15program_options8validateIdcEEvRNS_3anyERKSt6vectorISbIT0_St11char_traitsIS5_ESaIS5_EESaIS9_EEPT_l]+0x128): undefined reference to `boost::program_options::invalid_option_value::invalid_option_value(std::string const&)'
/tmp/ccNDtU66.o:(.rodata._ZTVN5boost16exception_detail10clone_implINS0_19error_info_injectorINS_15program_options16validation_errorEEEEE[_ZTVN5boost16exception_detail10clone_implINS0_19error_info_injectorINS_15program_options16validation_errorEEEEE]+0x38): undefined reference to `boost::program_options::error_with_option_name::substitute_placeholders(std::string const&) const'
/tmp/ccNDtU66.o:(.rodata._ZTVN5boost16exception_detail19error_info_injectorINS_15program_options16validation_errorEEE[_ZTVN5boost16exception_detail19error_info_injectorINS_15program_options16validation_errorEEE]+0x30): undefined reference to `boost::program_options::error_with_option_name::substitute_placeholders(std::string const&) const'
/tmp/ccNDtU66.o:(.rodata._ZTVN5boost16exception_detail10clone_implINS0_19error_info_injectorINS_15program_options20invalid_option_valueEEEEE[_ZTVN5boost16exception_detail10clone_implINS0_19error_info_injectorINS_15program_options20invalid_option_valueEEEEE]+0x38): undefined reference to `boost::program_options::error_with_option_name::substitute_placeholders(std::string const&) const'
/tmp/ccNDtU66.o:(.rodata._ZTVN5boost16exception_detail19error_info_injectorINS_15program_options20invalid_option_valueEEE[_ZTVN5boost16exception_detail19error_info_injectorINS_15program_options20invalid_option_valueEEE]+0x30): undefined reference to `boost::program_options::error_with_option_name::substitute_placeholders(std::string const&) const'
collect2: error: ld returned 1 exit status
Makefile:4: recipe for target 'first' failed
make: *** [first] Error 1
How do I fix this?
I am using Ubuntu 16.04, Intel(R) Core(TM) i5-6400 CPU # 2.70GHz

I noticed I used g++-4.8 and it seems that my version of boost (1.54.0) requires higher version. After I switched to g++-5 it compiles normally.

Related

cannot compile standalone asio with exceptions turned off

I'm trying to build project which uses standalone asio as dependency. Problem is that with exceptions turned off (-fno-exceptions), I have to define throw_exception function (link to boost documentation), but no matter how I define that function, linker throws undefined reference.
This is how I've tried to define throw_exception:
#define ASIO_NO_EXCEPTIONS
#include <asio/detail/throw_exception.hpp>
template <class E>
void asio::detail::throw_exception(E const& e) {
// do something
}
I receive these linking errors:
/usr/bin/ld: libsioclient.a(sio_socket.cpp.o): in function `asio::detail::do_throw_error(std::error_code const&, char const*) [clone .isra.0]':
sio_socket.cpp:(.text+0x333): undefined reference to `void asio::detail::throw_exception<std::system_error>(std::system_error const&)'
/usr/bin/ld: _libsioclient.a(sio_socket.cpp.o): in function `void asio::execution::detail::any_executor_base::query_fn<void, asio::execution::prefer_only<asio::execution::detail::outstanding_work::tracked_t<0> > >(void*, void const*, void const*)':
sio_socket.cpp:(.text._ZN4asio9execution6detail17any_executor_base8query_fnIvNS0_11prefer_onlyINS1_16outstanding_work9tracked_tILi0EEEEEEEvPvPKvSB_[_ZN4asio9execution6detail17any_executor_base8query_fnIvNS0_11prefer_onlyINS1_16outstanding_work9tracked_tILi0EEEEEEEvPvPKvSB_]+0x28): undefined reference to `void asio::detail::throw_exception<asio::execution::bad_executor>(asio::execution::bad_executor const&)'
/usr/bin/ld: libsioclient.a(sio_socket.cpp.o): in function `void asio::execution::detail::any_executor_base::query_fn<void, asio::execution::prefer_only<asio::execution::detail::outstanding_work::untracked_t<0> > >(void*, void const*, void const*)':
sio_socket.cpp:(.text._ZN4asio9execution6detail17any_executor_base8query_fnIvNS0_11prefer_onlyINS1_16outstanding_work11untracked_tILi0EEEEEEEvPvPKvSB_[_ZN4asio9execution6detail17any_executor_base8query_fnIvNS0_11prefer_onlyINS1_16outstanding_work11untracked_tILi0EEEEEEEvPvPKvSB_]+0x28): undefined reference to `void asio::detail::throw_exception<asio::execution::bad_executor>(asio::execution::bad_executor const&)'
/usr/bin/ld: libsioclient.a(sio_socket.cpp.o): in function `void asio::execution::detail::any_executor_base::query_fn<void, asio::execution::prefer_only<asio::execution::detail::relationship::fork_t<0> > >(void*, void const*, void const*)':
sio_socket.cpp:(.text._ZN4asio9execution6detail17any_executor_base8query_fnIvNS0_11prefer_onlyINS1_12relationship6fork_tILi0EEEEEEEvPvPKvSB_[_ZN4asio9execution6detail17any_executor_base8query_fnIvNS0_11prefer_onlyINS1_12relationship6fork_tILi0EEEEEEEvPvPKvSB_]+0x28): undefined reference to `void asio::detail::throw_exception<asio::execution::bad_executor>(asio::execution::bad_executor const&)'
/usr/bin/ld: libsioclient.a(sio_socket.cpp.o): in function `void asio::execution::detail::any_executor_base::query_fn<void, asio::execution::prefer_only<asio::execution::detail::relationship::continuation_t<0> > >(void*, void const*, void const*)':
sio_socket.cpp:(.text._ZN4asio9execution6detail17any_executor_base8query_fnIvNS0_11prefer_onlyINS1_12relationship14continuation_tILi0EEEEEEEvPvPKvSB_[_ZN4asio9execution6detail17any_executor_base8query_fnIvNS0_11prefer_onlyINS1_12relationship14continuation_tILi0EEEEEEEvPvPKvSB_]+0x28): undefined reference to `void asio::detail::throw_exception<asio::execution::bad_executor>(asio::execution::bad_executor const&)'
/usr/bin/ld: libsioclient.a(sio_socket.cpp.o): in function `void asio::execution::detail::any_executor_base::query_fn<void, asio::execution::context_as_t<asio::execution_context&> >(void*, void const*, void const*)':
sio_socket.cpp:(.text._ZN4asio9execution6detail17any_executor_base8query_fnIvNS0_12context_as_tIRNS_17execution_contextEEEEEvPvPKvSA_[_ZN4asio9execution6detail17any_executor_base8query_fnIvNS0_12context_as_tIRNS_17execution_contextEEEEEvPvPKvSA_]+0x28): undefined reference to `void asio::detail::throw_exception<asio::execution::bad_executor>(asio::execution::bad_executor const&)'
/usr/bin/ld: libsioclient.a(sio_socket.cpp.o):sio_socket.cpp:(.text._ZN4asio9execution6detail17any_executor_base10require_fnINS0_12any_executorIJNS0_12context_as_tIRNS_17execution_contextEEENS1_8blocking7never_tILi0EEENS0_11prefer_onlyINS9_10possibly_tILi0EEEEENSC_INS1_16outstanding_work9tracked_tILi0EEEEENSC_INSG_11untracked_tILi0EEEEENSC_INS1_12relationship6fork_tILi0EEEEENSC_INSN_14continuation_tILi0EEEEEEEEvS8_EET_PKvSX_[_ZN4asio9execution6detail17any_executor_base10require_fnINS0_12any_executorIJNS0_12context_as_tIRNS_17execution_contextEEENS1_8blocking7never_tILi0EEENS0_11prefer_onlyINS9_10possibly_tILi0EEEEENSC_INS1_16outstanding_work9tracked_tILi0EEEEENSC_INSG_11untracked_tILi0EEEEENSC_INS1_12relationship6fork_tILi0EEEEENSC_INSN_14continuation_tILi0EEEEEEEEvS8_EET_PKvSX_]+0x2d): more undefined references to `void asio::detail::throw_exception<asio::execution::bad_executor>(asio::execution::bad_executor const&)' follow
/usr/bin/ld: libsioclient.a(sio_socket.cpp.o): in function `asio::detail::scheduler::scheduler(asio::execution_context&, int, bool, asio::detail::scheduler_task* (*)(asio::execution_context&)) [clone .part.0]':
sio_socket.cpp:(.text._ZN4asio6detail9schedulerC2ERNS_17execution_contextEibPFPNS0_14scheduler_taskES3_E.part.0[_ZN4asio6detail9schedulerC5ERNS_17execution_contextEibPFPNS0_14scheduler_taskES3_E]+0x228): undefined reference to `void asio::detail::throw_exception<std::system_error>(std::system_error const&)'
/usr/bin/ld: libsioclient.a(sio_socket.cpp.o): in function `asio::detail::epoll_reactor::notify_fork(asio::execution_context::fork_event)':
sio_socket.cpp:(.text._ZN4asio6detail13epoll_reactor11notify_forkENS_17execution_context10fork_eventE[_ZN4asio6detail13epoll_reactor11notify_forkENS_17execution_context10fork_eventE]+0x375): undefined reference to `void asio::detail::throw_exception<std::system_error>(std::system_error const&)'
/usr/bin/ld: libsioclient.a(sio_socket.cpp.o): in function `asio::detail::scheduler::scheduler(asio::execution_context&, int, bool, asio::detail::scheduler_task* (*)(asio::execution_context&))':
sio_socket.cpp:(.text._ZN4asio6detail9schedulerC2ERNS_17execution_contextEibPFPNS0_14scheduler_taskES3_E[_ZN4asio6detail9schedulerC5ERNS_17execution_contextEibPFPNS0_14scheduler_taskES3_E]+0x24a): undefined reference to `void asio::detail::throw_exception<std::system_error>(std::system_error const&)'
/usr/bin/ld: sio_socket.cpp:(.text._ZN4asio6detail9schedulerC2ERNS_17execution_contextEibPFPNS0_14scheduler_taskES3_E[_ZN4asio6detail9schedulerC5ERNS_17execution_contextEibPFPNS0_14scheduler_taskES3_E]+0x4f7): undefined reference to `void asio::detail::throw_exception<std::system_error>(std::system_error const&)'
/usr/bin/ld: libsioclient.a(sio_socket.cpp.o): in function `asio::execution_context::service* asio::detail::service_registry::create<asio::detail::epoll_reactor, asio::execution_context>(void*)':
sio_socket.cpp:(.text._ZN4asio6detail16service_registry6createINS0_13epoll_reactorENS_17execution_contextEEEPNS4_7serviceEPv[_ZN4asio6detail16service_registry6createINS0_13epoll_reactorENS_17execution_contextEEEPNS4_7serviceEPv]+0x5d6): undefined reference to `void asio::detail::throw_exception<std::system_error>(std::system_error const&)'
/usr/bin/ld: libsioclient.a(sio_client_impl.cpp.o): in function `std::_Function_handler<void (bool, std::shared_ptr<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const> const&), sio::client_impl::on_ping()::{lambda(bool, std::shared_ptr<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const>)#1}>::_M_invoke(std::_Any_data const&, bool&&, std::shared_ptr<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const> const&)':
sio_client_impl.cpp:(.text+0x3c40): undefined reference to `websocketpp::endpoint<websocketpp::connection<websocketpp::config::asio_client>, websocketpp::config::asio_client>::send(std::weak_ptr<void>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, websocketpp::frame::opcode::value)'
/usr/bin/ld: libsioclient.a(sio_client_impl.cpp.o): in function `sio::client_impl::connect_impl(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
sio_client_impl.cpp:(.text+0x988c): undefined reference to `websocketpp::connection<websocketpp::config::asio_client>::replace_header(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
How to properly define throw_exception function or if I'm missing something, how can these errors be solved?
You can try this, log() is the imaginary function you already use for logging ...
// somechere in a cpp file, preferably.
#include <boost/asio.hpp>
// ...
namespace boost::asio::detail {
template<>
void throw_exception(const asio::execution::bad_executor& e)
{
// throw e; // this is what the original function does
LOG("asio::execution::bad_executor thrown\n"); // etc...
exit(3); // That's all you can do at this point.
}
template<>
void throw_exception(const std::system_error& e)
{
LOG("std::system_error thrown\n"); // etc...
exit(3); // That's all you can do at this point.
}
}
You may need to declare more specializations as you go along.
I find solution. Problem was that compiler threw implementation of throw_exception from code while compiling, and when linker tried to find that function, there simply was no throw_exception. I made it like this:
namespace asio::detail {
template <typename Exception> void throw_exception(const Exception& e) {
std::cerr << "Something went wrong..." << std::endl;
std::terminate();
}
}; // namespace asio::detail
If I call this function somewhere, I don't receive linking errors. Probably, I have to implement some kind of error handling instead of that and find a solution to make this function properly compiled and linked, but, at least, I've found a reason of that strange behaviour.

Running the Examples from WebRTC C++ source code

I am trying to run the examples in C++ from the WebRTC source code, using the native API(not building)
My Cmakelist is:
cmake_minimum_required(VERSION 3.5)
project(WebRTC)
include_directories("D:/Clion_Projects/src/api")
include_directories("D:/abseil-cpp")
include_directories("D:/CLion_Projects/src/")
add_executable(main examples/peerconnection/server/main.cc)
And the code is:
/*
* Copyright 2011 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#if defined(WEBRTC_POSIX)
#include <sys/select.h>
#endif
#include <time.h>
#include <string>
#include <vector>
#include "absl/flags/flag.h"
#include "absl/flags/parse.h"
#include "absl/flags/usage.h"
#include "examples/peerconnection/server/data_socket.h"
#include "examples/peerconnection/server/peer_channel.h"
#include "system_wrappers/include/field_trial.h"
#include "test/field_trial.h"
ABSL_FLAG(
std::string,
force_fieldtrials,
"",
"Field trials control experimental features. This flag specifies the field "
"trials in effect. E.g. running with "
"--force_fieldtrials=WebRTC-FooFeature/Enabled/ "
"will assign the group Enabled to field trial WebRTC-FooFeature. Multiple "
"trials are separated by \"/\"");
ABSL_FLAG(int, port, 8888, "default: 8888");
static const size_t kMaxConnections = (FD_SETSIZE - 2);
void HandleBrowserRequest(DataSocket *ds, bool *quit) {
assert(ds && ds->valid());
assert(quit);
const std::string &path = ds->request_path();
*quit = (path.compare("/quit") == 0);
if (*quit) {
ds->Send("200 OK", true, "text/html", "",
"<html><body>Quitting...</body></html>");
} else if (ds->method() == DataSocket::OPTIONS) {
// We'll get this when a browsers do cross-resource-sharing requests.
// The headers to allow cross-origin script support will be set inside
// Send.
ds->Send("200 OK", true, "", "", "");
} else {
// Here we could write some useful output back to the browser depending on
// the path.
printf("Received an invalid request: %s\n", ds->request_path().c_str());
ds->Send("500 Sorry", true, "text/html", "",
"<html><body>Sorry, not yet implemented</body></html>");
}
}
int main(int argc, char *argv[]) {
absl::SetProgramUsageMessage(
"Example usage: ./peerconnection_server --port=8888\n");
absl::ParseCommandLine(argc, argv);
// InitFieldTrialsFromString stores the char*, so the char array must outlive
// the application.
const std::string force_field_trials = absl::GetFlag(FLAGS_force_fieldtrials);
webrtc::field_trial::InitFieldTrialsFromString(force_field_trials.c_str());
int port = absl::GetFlag(FLAGS_port);
// Abort if the user specifies a port that is outside the allowed
// range [1, 65535].
if ((port < 1) || (port > 65535)) {
printf("Error: %i is not a valid port.\n", port);
return -1;
}
ListeningSocket listener;
if (!listener.Create()) {
printf("Failed to create server socket\n");
return -1;
} else if (!listener.Listen(port)) {
printf("Failed to listen on server socket\n");
return -1;
}
printf("Server listening on port %i\n", port);
PeerChannel clients;
typedef std::vector<DataSocket *> SocketArray;
SocketArray sockets;
bool quit = false;
while (!quit) {
fd_set socket_set;
FD_ZERO(&socket_set);
if (listener.valid())
FD_SET(listener.socket(), &socket_set);
for (SocketArray::iterator i = sockets.begin(); i != sockets.end(); ++i)
FD_SET((*i)->socket(), &socket_set);
struct timeval timeout = {10, 0};
if (select(FD_SETSIZE, &socket_set, NULL, NULL, &timeout) == SOCKET_ERROR) {
printf("select failed\n");
break;
}
for (SocketArray::iterator i = sockets.begin(); i != sockets.end(); ++i) {
DataSocket *s = *i;
bool socket_done = true;
if (FD_ISSET(s->socket(), &socket_set)) {
if (s->OnDataAvailable(&socket_done) && s->request_received()) {
ChannelMember *member = clients.Lookup(s);
if (member || PeerChannel::IsPeerConnection(s)) {
if (!member) {
if (s->PathEquals("/sign_in")) {
clients.AddMember(s);
} else {
printf("No member found for: %s\n", s->request_path().c_str());
s->Send("500 Error", true, "text/plain", "",
"Peer most likely gone.");
}
} else if (member->is_wait_request(s)) {
// no need to do anything.
socket_done = false;
} else {
ChannelMember *target = clients.IsTargetedRequest(s);
if (target) {
member->ForwardRequestToPeer(s, target);
} else if (s->PathEquals("/sign_out")) {
s->Send("200 OK", true, "text/plain", "", "");
} else {
printf("Couldn't find target for request: %s\n",
s->request_path().c_str());
s->Send("500 Error", true, "text/plain", "",
"Peer most likely gone.");
}
}
} else {
HandleBrowserRequest(s, &quit);
if (quit) {
printf("Quitting...\n");
FD_CLR(listener.socket(), &socket_set);
listener.Close();
clients.CloseAll();
}
}
}
} else {
socket_done = false;
}
if (socket_done) {
printf("Disconnecting socket\n");
clients.OnClosing(s);
assert(s->valid()); // Close must not have been called yet.
FD_CLR(s->socket(), &socket_set);
delete (*i);
i = sockets.erase(i);
if (i == sockets.end())
break;
}
}
clients.CheckForTimeout();
if (FD_ISSET(listener.socket(), &socket_set)) {
DataSocket *s = listener.Accept();
if (sockets.size() >= kMaxConnections) {
delete s; // sorry, that's all we can take.
printf("Connection limit reached\n");
} else {
sockets.push_back(s);
printf("New connection...\n");
}
}
}
for (SocketArray::iterator i = sockets.begin(); i != sockets.end(); ++i)
delete (*i);
sockets.clear();
return 0;
}
But even after configuring the CmakeList I run into these errors:
Scanning dependencies of target main
[ 50%] Building CXX object CMakeFiles/main.dir/examples/peerconnection/server/main.cc.obj
[100%] Linking CXX executable main.exe
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `HandleBrowserRequest(DataSocket*, bool*)':
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:55: undefined reference to `DataSocket::Send(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:61: undefined reference to `DataSocket::Send(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:66: undefined reference to `DataSocket::Send(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `main':
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:72: undefined reference to `absl::SetProgramUsageMessage(absl::string_view)'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:74: undefined reference to `absl::ParseCommandLine(int, char**)'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:79: undefined reference to `webrtc::field_trial::InitFieldTrialsFromString(char const*)'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:91: undefined reference to `SocketBase::Create()'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:94: undefined reference to `ListeningSocket::Listen(unsigned short)'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:115: undefined reference to `__imp_select'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:123: undefined reference to `__WSAFDIsSet'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:124: undefined reference to `DataSocket::OnDataAvailable(bool*)'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:125: undefined reference to `PeerChannel::Lookup(DataSocket*) const'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:126: undefined reference to `PeerChannel::IsPeerConnection(DataSocket const*)'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:128: undefined reference to `DataSocket::PathEquals(char const*) const'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:129: undefined reference to `PeerChannel::AddMember(DataSocket*)'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:132: undefined reference to `DataSocket::Send(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:135: undefined reference to `ChannelMember::is_wait_request(DataSocket*) const'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:139: undefined reference to `PeerChannel::IsTargetedRequest(DataSocket const*) const'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:141: undefined reference to `ChannelMember::ForwardRequestToPeer(DataSocket*, ChannelMember*)'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:142: undefined reference to `DataSocket::PathEquals(char const*) const'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:143: undefined reference to `DataSocket::Send(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:147: undefined reference to `DataSocket::Send(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:156: undefined reference to `SocketBase::Close()'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:157: undefined reference to `PeerChannel::CloseAll()'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:167: undefined reference to `PeerChannel::OnClosing(DataSocket*)'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:177: undefined reference to `PeerChannel::CheckForTimeout()'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:179: undefined reference to `__WSAFDIsSet'
D:/CLion_Projects/src/examples/peerconnection/server/main.cc:180: undefined reference to `ListeningSocket::Accept() const'
CMakeFiles\main.dir/objects.a(main.cc.obj):main.cc:(.data+0x0): undefined reference to `vtable for absl::flags_internal::FlagImpl'
CMakeFiles\main.dir/objects.a(main.cc.obj):D:/CLion_Projects/src/examples/peerconnection/server/main.cc:42: undefined reference to `vtable for absl::flags_internal::FlagImpl'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `SocketBase::~SocketBase()':
D:/CLion_Projects/src/examples/peerconnection/server/data_socket.h:40: undefined reference to `SocketBase::Close()'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `PeerChannel::~PeerChannel()':
D:/CLion_Projects/src/examples/peerconnection/server/peer_channel.h:75: undefined reference to `PeerChannel::DeleteAll()'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `absl::flags_internal::FlagRegistrar<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, true>::FlagRegistrar(absl::flags_internal::Flag<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >&, char const*)':
D:/abseil-cpp/absl/flags/internal/flag.h:726: undefined reference to `absl::flags_internal::RegisterCommandLineFlag(absl::CommandLineFlag&, char const*)'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `absl::flags_internal::FlagRegistrar<int, true>::FlagRegistrar(absl::flags_internal::Flag<int>&, char const*)':
D:/abseil-cpp/absl/flags/internal/flag.h:726: undefined reference to `absl::flags_internal::RegisterCommandLineFlag(absl::CommandLineFlag&, char const*)'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > absl::UnparseFlag<int>(int const&)':
D:/abseil-cpp/absl/flags/marshalling.h:251: undefined reference to `absl::flags_internal::Unparse[abi:cxx11](int)'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `bool absl::flags_internal::InvokeParseFlag<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >(absl::string_view, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*)':
D:/abseil-cpp/absl/flags/marshalling.h:195: undefined reference to `absl::flags_internal::AbslParseFlag(absl::string_view, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*)'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > absl::flags_internal::Unparse<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
D:/abseil-cpp/absl/flags/marshalling.h:208: undefined reference to `absl::flags_internal::AbslUnparseFlag[abi:cxx11](absl::string_view)'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `bool absl::flags_internal::InvokeParseFlag<int>(absl::string_view, int*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*)':
D:/abseil-cpp/absl/flags/marshalling.h:195: undefined reference to `absl::flags_internal::AbslParseFlag(absl::string_view, int*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*)'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `absl::flags_internal::Flag<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::Get() const':
D:/abseil-cpp/absl/flags/internal/flag.h:618: undefined reference to `absl::flags_internal::FlagImpl::AssertValidType(void const*, std::type_info const* (*)()) const'
D:/abseil-cpp/absl/flags/internal/flag.h:622: undefined reference to `absl::flags_internal::FlagImpl::Read(void*) const'
CMakeFiles\main.dir/objects.a(main.cc.obj): In function `absl::flags_internal::Flag<int>::Get() const':
D:/abseil-cpp/absl/flags/internal/flag.h:618: undefined reference to `absl::flags_internal::FlagImpl::AssertValidType(void const*, std::type_info const* (*)()) const'
D:/abseil-cpp/absl/flags/internal/flag.h:622: undefined reference to `absl::flags_internal::FlagImpl::Read(void*) const'
collect2.exe: error: ld returned 1 exit status
mingw32-make.exe[3]: *** [CMakeFiles\main.dir\build.make:106: main.exe] Error 1
mingw32-make.exe[2]: *** [CMakeFiles\Makefile2:95: CMakeFiles/main.dir/all] Error 2
mingw32-make.exe[1]: *** [CMakeFiles\Makefile2:102: CMakeFiles/main.dir/rule] Error 2
mingw32-make.exe: *** [Makefile:137: main] Error 2
I don't understand why I am getting these errors, since I am running the example as is from the repo.
Any help would be greatly appreciated!

OpenABE C++ Library: Undefined Reference Error

I have successfully installed the OpenABE Library - https://github.com/zeutro/openabe
But when I try to compile my own program or run the example - https://github.com/zeutro/openabe/blob/master/examples/test_cp.cpp
g++ test.cpp
I get the Error:
/tmp/ccAcWSoq.o: In function main':
test.cpp:(.text+0x29): undefined reference tooabe::InitializeOpenABE()'
test.cpp:(.text+0x6a): undefined reference to oabe::OpenABECryptoContext::OpenABECryptoContext(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool)'
test.cpp:(.text+0xea): undefined reference tooabe::OpenABECryptoContext::generateParams()'
test.cpp:(.text+0x1bf): undefined reference to oabe::OpenABECryptoContext::keygen(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
test.cpp:(.text+0x27b): undefined reference tooabe::OpenABECryptoContext::encrypt(std::__cxx11::basic_string, std::allocator >, std::__cxx11::basic_string, std::allocator > const&, std::__cxx11::basic_string, std::allocator >&)'
test.cpp:(.text+0x2dd): undefined reference to oabe::OpenABECryptoContext::decrypt(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)'
test.cpp:(.text+0x385): undefined reference tooabe::ShutdownOpenABE()'
/tmp/ccAcWSoq.o: In function oabe::OpenABECryptoContext::~OpenABECryptoContext()':
test.cpp:(.text._ZN4oabe20OpenABECryptoContextD2Ev[_ZN4oabe20OpenABECryptoContextD5Ev]+0xf): undefined reference tovtable for oabe::OpenABECryptoContext'
collect2: error: ld returned 1 exit status
Here is the code - test.cpp
#include <iostream>
#include <string>
#include <cassert>
#include <openabe/openabe.h>
#include <openabe/zsymcrypto.h>
using namespace std;
using namespace oabe;
using namespace oabe::crypto;
int main(int argc, char **argv){
InitializeOpenABE();
OpenABECryptoContext cpabe("CP-ABE");
string ct, pt1 = "plaintext", pt2;
cpabe.generateParams();
cpabe.keygen("|attr1|attr2","key0");
cpabe.encrypt("attr1 and attr2",pt1,ct);
bool result = cpabe.decrypt("key0",ct,pt2);
assert(result && pt1 == pt2);
cout << "Message: " << pt2 << endl;
ShutdownOpenABE();
return 0;
}
Am I even compiling the file correctly?
Or is there any other issue that I cannot seem to identify?

C++ OpenCV 3.1.0 linking error (ubuntu)

I am a C++ newbie trying to compile some OpenCV tutorial code.
I'm running Ubuntu 16.04, and I installed OpenCV 3.1.0 with this script: https://github.com/milq/scripts-ubuntu-debian/blob/master/install-opencv.sh
The source file I'm trying to compile is here:
https://github.com/opencv/opencv/blob/master/samples/cpp/tutorial_code/calib3d/camera_calibration/camera_calibration.cpp
I wrote this makefile:
CC=g++
CFLAGS = `pkg-config --cflags opencv` -c -g
LIBS = `pkg-config --libs opencv`
all: camcalib
camcalib: camera_calibration.o
$(CC) camera_calibration.o -o camcalib
camera_calibration.o: camera_calibration.cpp
$(CC) $(CFLAGS) $(LIBS) camera_calibration.cpp
clean:
rm *o camcalib
When I "make", the camera_calibration.o object file is generated, but I get the following error during linking:
make
g++ `pkg-config --cflags opencv` -c -g `pkg-config --libs opencv` camera_calibration.cpp
g++ camera_calibration.o -o camcalib
camera_calibration.o: In function `cv::read(cv::FileNode const&, bool&, bool)':
/usr/local/include/opencv2/core/persistence.hpp:996: undefined reference to `cv::read(cv::FileNode const&, int&, int)'
camera_calibration.o: In function `cv::operator<<(cv::FileStorage&, char const*)':
/usr/local/include/opencv2/core/persistence.hpp:1076: undefined reference to `cv::operator<<(cv::FileStorage&, cv::String const&)'
camera_calibration.o: In function `cv::operator<<(cv::FileStorage&, char*)':
/usr/local/include/opencv2/core/persistence.hpp:1084: undefined reference to `cv::operator<<(cv::FileStorage&, cv::String const&)'
camera_calibration.o: In function `void cv::operator>><std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >(cv::FileNode const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)':
/usr/local/include/opencv2/core/cvstd.inl.hpp:155: undefined reference to `cv::read(cv::FileNode const&, cv::String&, cv::String const&)'
camera_calibration.o: In function `main':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:239: undefined reference to `cv::FileStorage::FileStorage(cv::String const&, int, cv::String const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:240: undefined reference to `cv::FileStorage::isOpened() const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:245: undefined reference to `cv::FileStorage::operator[](char const*) const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:246: undefined reference to `cv::FileStorage::release()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:292: undefined reference to `cv::flip(cv::_InputArray const&, cv::_OutputArray const&, int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:309: undefined reference to `cv::findChessboardCorners(cv::_InputArray const&, cv::Size_<int>, cv::_OutputArray const&, int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:312: undefined reference to `cv::SimpleBlobDetector::Params::Params()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:312: undefined reference to `cv::SimpleBlobDetector::create(cv::SimpleBlobDetector::Params const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:312: undefined reference to `cv::findCirclesGrid(cv::_InputArray const&, cv::Size_<int>, cv::_OutputArray const&, int, cv::Ptr<cv::Feature2D> const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:315: undefined reference to `cv::SimpleBlobDetector::Params::Params()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:315: undefined reference to `cv::SimpleBlobDetector::create(cv::SimpleBlobDetector::Params const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:315: undefined reference to `cv::findCirclesGrid(cv::_InputArray const&, cv::Size_<int>, cv::_OutputArray const&, int, cv::Ptr<cv::Feature2D> const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:329: undefined reference to `cv::cvtColor(cv::_InputArray const&, cv::_OutputArray const&, int, int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:331: undefined reference to `cv::cornerSubPix(cv::_InputArray const&, cv::_InputOutputArray const&, cv::Size_<int>, cv::Size_<int>, cv::TermCriteria)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:335: undefined reference to `cv::VideoCapture::isOpened() const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:339: undefined reference to `cv::VideoCapture::isOpened() const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:343: undefined reference to `cv::drawChessboardCorners(cv::_InputOutputArray const&, cv::Size_<int>, cv::_InputArray const&, bool)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:351: undefined reference to `cv::getTextSize(cv::String const&, int, double, int, int*)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:357: undefined reference to `cv::format(char const*, ...)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:359: undefined reference to `cv::format(char const*, ...)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:362: undefined reference to `cv::putText(cv::_InputOutputArray const&, cv::String const&, cv::Point_<int>, int, double, cv::Scalar_<double>, int, int, bool)'
camera_calibration.o: In function `main':
/usr/local/include/opencv2/core.hpp:1257: undefined reference to `cv::noArray()'
camera_calibration.o: In function `main':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:365: undefined reference to `cv::bitwise_not(cv::_InputArray const&, cv::_OutputArray const&, cv::_InputArray const&)'
camera_calibration.o: In function `main':
/usr/local/include/opencv2/imgproc.hpp:2609: undefined reference to `cv::noArray()'
camera_calibration.o: In function `main':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:372: undefined reference to `cv::undistort(cv::_InputArray const&, cv::_OutputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:377: undefined reference to `cv::imshow(cv::String const&, cv::_InputArray const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:378: undefined reference to `cv::VideoCapture::isOpened() const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:378: undefined reference to `cv::waitKey(int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:386: undefined reference to `cv::VideoCapture::isOpened() const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:404: undefined reference to `cv::fisheye::estimateNewCameraMatrixForUndistortRectify(cv::_InputArray const&, cv::_InputArray const&, cv::Size_<int> const&, cv::_InputArray const&, cv::_OutputArray const&, double, cv::Size_<int> const&, double)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:406: undefined reference to `cv::fisheye::initUndistortRectifyMap(cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::Size_<int> const&, int, cv::_OutputArray const&, cv::_OutputArray const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:412: undefined reference to `cv::getOptimalNewCameraMatrix(cv::_InputArray const&, cv::_InputArray const&, cv::Size_<int>, double, cv::Size_<int>, cv::Rect_<int>*, bool)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:413: undefined reference to `cv::initUndistortRectifyMap(cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::Size_<int>, int, cv::_OutputArray const&, cv::_OutputArray const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:418: undefined reference to `cv::imread(cv::String const&, int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:421: undefined reference to `cv::remap(cv::_InputArray const&, cv::_OutputArray const&, cv::_InputArray const&, cv::_InputArray const&, int, int, cv::Scalar_<double> const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:422: undefined reference to `cv::imshow(cv::String const&, cv::_InputArray const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:423: undefined reference to `cv::waitKey(int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:239: undefined reference to `cv::FileStorage::~FileStorage()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:431: undefined reference to `cv::FileStorage::~FileStorage()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:431: undefined reference to `cv::FileStorage::~FileStorage()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:239: undefined reference to `cv::FileStorage::~FileStorage()'
camera_calibration.o: In function `computeReprojectionErrors(std::vector<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > >, std::allocator<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > > > > const&, std::vector<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > >, std::allocator<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > > > > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, cv::Mat const&, cv::Mat const&, std::vector<float, std::allocator<float> >&, bool)':
/usr/local/include/opencv2/calib3d.hpp:1795: undefined reference to `cv::noArray()'
camera_calibration.o: In function `computeReprojectionErrors(std::vector<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > >, std::allocator<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > > > > const&, std::vector<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > >, std::allocator<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > > > > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, cv::Mat const&, cv::Mat const&, std::vector<float, std::allocator<float> >&, bool)':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:450: undefined reference to `cv::fisheye::projectPoints(cv::_InputArray const&, cv::_OutputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, double, cv::_OutputArray const&)'
camera_calibration.o: In function `computeReprojectionErrors(std::vector<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > >, std::allocator<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > > > > const&, std::vector<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > >, std::allocator<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > > > > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, cv::Mat const&, cv::Mat const&, std::vector<float, std::allocator<float> >&, bool)':
/usr/local/include/opencv2/calib3d.hpp:513: undefined reference to `cv::noArray()'
camera_calibration.o: In function `computeReprojectionErrors(std::vector<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > >, std::allocator<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > > > > const&, std::vector<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > >, std::allocator<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > > > > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, cv::Mat const&, cv::Mat const&, std::vector<float, std::allocator<float> >&, bool)':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:454: undefined reference to `cv::projectPoints(cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_OutputArray const&, cv::_OutputArray const&, double)'
camera_calibration.o: In function `computeReprojectionErrors(std::vector<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > >, std::allocator<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > > > > const&, std::vector<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > >, std::allocator<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > > > > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, cv::Mat const&, cv::Mat const&, std::vector<float, std::allocator<float> >&, bool)':
/usr/local/include/opencv2/core.hpp:668: undefined reference to `cv::noArray()'
camera_calibration.o: In function `computeReprojectionErrors(std::vector<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > >, std::allocator<std::vector<cv::Point3_<float>, std::allocator<cv::Point3_<float> > > > > const&, std::vector<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > >, std::allocator<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > > > > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, cv::Mat const&, cv::Mat const&, std::vector<float, std::allocator<float> >&, bool)':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:456: undefined reference to `cv::norm(cv::_InputArray const&, cv::_InputArray const&, int, cv::_InputArray const&)'
camera_calibration.o: In function `runCalibration(Settings&, cv::Size_<int>&, cv::Mat&, cv::Mat&, std::vector<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > >, std::allocator<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > > > >, std::vector<cv::Mat, std::allocator<cv::Mat> >&, std::vector<cv::Mat, std::allocator<cv::Mat> >&, std::vector<float, std::allocator<float> >&, double&)':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:497: undefined reference to `cv::Mat::eye(int, int, int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:502: undefined reference to `cv::Mat::zeros(int, int, int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:504: undefined reference to `cv::Mat::zeros(int, int, int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:518: undefined reference to `cv::fisheye::calibrate(cv::_InputArray const&, cv::_InputArray const&, cv::Size_<int> const&, cv::_InputOutputArray const&, cv::_InputOutputArray const&, cv::_OutputArray const&, cv::_OutputArray const&, int, cv::TermCriteria)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:528: undefined reference to `cv::calibrateCamera(cv::_InputArray const&, cv::_InputArray const&, cv::Size_<int>, cv::_InputOutputArray const&, cv::_InputOutputArray const&, cv::_OutputArray const&, cv::_OutputArray const&, int, cv::TermCriteria)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:533: undefined reference to `cv::checkRange(cv::_InputArray const&, bool, cv::Point_<int>*, double, double)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:533: undefined reference to `cv::checkRange(cv::_InputArray const&, bool, cv::Point_<int>*, double, double)'
camera_calibration.o: In function `saveCameraParams(Settings&, cv::Size_<int>&, cv::Mat&, cv::Mat&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, std::vector<cv::Mat, std::allocator<cv::Mat> > const&, std::vector<float, std::allocator<float> > const&, std::vector<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > >, std::allocator<std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > > > > const&, double)':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:547: undefined reference to `cv::FileStorage::FileStorage(cv::String const&, int, cv::String const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:588: undefined reference to `cvWriteComment'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:604: undefined reference to `cv::error(int, cv::String const&, char const*, char const*, int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:611: undefined reference to `cv::error(int, cv::String const&, char const*, char const*, int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:612: undefined reference to `cv::error(int, cv::String const&, char const*, char const*, int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:614: undefined reference to `cv::Mat::t() const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:615: undefined reference to `cv::Mat::t() const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:626: undefined reference to `cv::Mat::reshape(int, int) const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:628: undefined reference to `cv::Mat::copyTo(cv::_OutputArray const&) const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:547: undefined reference to `cv::FileStorage::~FileStorage()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:632: undefined reference to `cv::FileStorage::~FileStorage()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:632: undefined reference to `cv::FileStorage::~FileStorage()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:547: undefined reference to `cv::FileStorage::~FileStorage()'
camera_calibration.o: In function `cv::FileStorage& cv::operator<< <int>(cv::FileStorage&, int const&)':
/usr/local/include/opencv2/core/persistence.hpp:1064: undefined reference to `cv::error(int, cv::String const&, char const*, char const*, int)'
/usr/local/include/opencv2/core/persistence.hpp:1065: undefined reference to `cv::write(cv::FileStorage&, cv::String const&, int)'
camera_calibration.o: In function `cv::FileStorage& cv::operator<< <float>(cv::FileStorage&, float const&)':
/usr/local/include/opencv2/core/persistence.hpp:1064: undefined reference to `cv::error(int, cv::String const&, char const*, char const*, int)'
/usr/local/include/opencv2/core/persistence.hpp:1065: undefined reference to `cv::write(cv::FileStorage&, cv::String const&, float)'
camera_calibration.o: In function `cv::FileStorage& cv::operator<< <bool>(cv::FileStorage&, bool const&)':
/usr/local/include/opencv2/core/persistence.hpp:1064: undefined reference to `cv::error(int, cv::String const&, char const*, char const*, int)'
/usr/local/include/opencv2/core/persistence.hpp:1065: undefined reference to `cv::write(cv::FileStorage&, cv::String const&, int)'
camera_calibration.o: In function `void cv::operator>><int>(cv::FileNode const&, int&)':
/usr/local/include/opencv2/core/persistence.hpp:1121: undefined reference to `cv::read(cv::FileNode const&, int&, int)'
camera_calibration.o: In function `void cv::operator>><float>(cv::FileNode const&, float&)':
/usr/local/include/opencv2/core/persistence.hpp:1121: undefined reference to `cv::read(cv::FileNode const&, float&, float)'
camera_calibration.o: In function `cv::FileStorage& cv::operator<< <cv::Mat>(cv::FileStorage&, cv::Mat const&)':
/usr/local/include/opencv2/core/persistence.hpp:1064: undefined reference to `cv::error(int, cv::String const&, char const*, char const*, int)'
/usr/local/include/opencv2/core/persistence.hpp:1065: undefined reference to `cv::write(cv::FileStorage&, cv::String const&, cv::Mat const&)'
camera_calibration.o: In function `cv::FileStorage& cv::operator<< <double>(cv::FileStorage&, double const&)':
/usr/local/include/opencv2/core/persistence.hpp:1064: undefined reference to `cv::error(int, cv::String const&, char const*, char const*, int)'
/usr/local/include/opencv2/core/persistence.hpp:1065: undefined reference to `cv::write(cv::FileStorage&, cv::String const&, double)'
camera_calibration.o: In function `cv::String::String(char const*)':
/usr/local/include/opencv2/core/cvstd.hpp:625: undefined reference to `cv::String::allocate(unsigned long)'
camera_calibration.o: In function `cv::String::~String()':
/usr/local/include/opencv2/core/cvstd.hpp:667: undefined reference to `cv::String::deallocate()'
camera_calibration.o: In function `cv::Mat::Mat(cv::Mat const&)':
/usr/local/include/opencv2/core/mat.inl.hpp:400: undefined reference to `cv::Mat::copySize(cv::Mat const&)'
camera_calibration.o: In function `cv::Mat::Mat(int, int, int, void*, unsigned long)':
/usr/local/include/opencv2/core/mat.inl.hpp:410: undefined reference to `cv::error(int, cv::String const&, char const*, char const*, int)'
/usr/local/include/opencv2/core/mat.inl.hpp:426: undefined reference to `cv::error(int, cv::String const&, char const*, char const*, int)'
camera_calibration.o: In function `cv::Mat::~Mat()':
/usr/local/include/opencv2/core/mat.inl.hpp:571: undefined reference to `cv::fastFree(void*)'
camera_calibration.o: In function `cv::Mat::operator=(cv::Mat const&)':
/usr/local/include/opencv2/core/mat.inl.hpp:592: undefined reference to `cv::Mat::copySize(cv::Mat const&)'
camera_calibration.o: In function `cv::Mat::row(int) const':
/usr/local/include/opencv2/core/mat.inl.hpp:606: undefined reference to `cv::Mat::Mat(cv::Mat const&, cv::Range const&, cv::Range const&)'
camera_calibration.o: In function `cv::Mat::clone() const':
/usr/local/include/opencv2/core/mat.inl.hpp:643: undefined reference to `cv::Mat::copyTo(cv::_OutputArray const&) const'
camera_calibration.o: In function `cv::Mat::create(int, int, int)':
/usr/local/include/opencv2/core/mat.inl.hpp:663: undefined reference to `cv::Mat::create(int, int const*, int)'
camera_calibration.o: In function `cv::Mat::release()':
/usr/local/include/opencv2/core/mat.inl.hpp:682: undefined reference to `cv::Mat::deallocate()'
camera_calibration.o: In function `cv::Mat::operator()(cv::Range, cv::Range) const':
/usr/local/include/opencv2/core/mat.inl.hpp:692: undefined reference to `cv::Mat::Mat(cv::Mat const&, cv::Range const&, cv::Range const&)'
camera_calibration.o: In function `cv::FileStorage::getFirstTopLevelNode() const':
/usr/local/include/opencv2/core/persistence.hpp:1167: undefined reference to `cv::FileStorage::root(int) const'
camera_calibration.o: In function `cv::FileNode::begin() const':
/usr/local/include/opencv2/core/persistence.hpp:1184: undefined reference to `cv::FileNodeIterator::FileNodeIterator(CvFileStorage const*, CvFileNode const*, unsigned long)'
camera_calibration.o: In function `cv::FileNode::end() const':
/usr/local/include/opencv2/core/persistence.hpp:1185: undefined reference to `cv::FileNode::size() const'
/usr/local/include/opencv2/core/persistence.hpp:1185: undefined reference to `cv::FileNodeIterator::FileNodeIterator(CvFileStorage const*, CvFileNode const*, unsigned long)'
camera_calibration.o: In function `cv::String::String(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
/usr/local/include/opencv2/core/cvstd.inl.hpp:81: undefined reference to `cv::String::allocate(unsigned long)'
camera_calibration.o: In function `cv::FileNode::operator std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >[abi:cxx11]() const':
/usr/local/include/opencv2/core/cvstd.inl.hpp:147: undefined reference to `cv::read(cv::FileNode const&, cv::String&, cv::String const&)'
camera_calibration.o: In function `Settings::Settings()':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:31: undefined reference to `cv::VideoCapture::VideoCapture()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:31: undefined reference to `cv::VideoCapture::~VideoCapture()'
camera_calibration.o: In function `Settings::read(cv::FileNode const&)':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:60: undefined reference to `cv::FileNode::operator[](char const*) const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:61: undefined reference to `cv::FileNode::operator[](char const*) const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:62: undefined reference to `cv::FileNode::operator[](char const*) const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:63: undefined reference to `cv::FileNode::operator[](char const*) const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:64: undefined reference to `cv::FileNode::operator[](char const*) const'
camera_calibration.o:/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:65: more undefined references to `cv::FileNode::operator[](char const*) const' follow
camera_calibration.o: In function `Settings::validate()':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:118: undefined reference to `cv::VideoCapture::open(int)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:120: undefined reference to `cv::VideoCapture::open(cv::String const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:121: undefined reference to `cv::VideoCapture::isOpened() const'
camera_calibration.o: In function `Settings::nextImage()':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:157: undefined reference to `cv::VideoCapture::isOpened() const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:160: undefined reference to `cv::VideoCapture::operator>>(cv::Mat&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:161: undefined reference to `cv::Mat::copyTo(cv::_OutputArray const&) const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:164: undefined reference to `cv::imread(cv::String const&, int)'
camera_calibration.o: In function `Settings::readStringList(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&)':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:172: undefined reference to `cv::FileStorage::FileStorage(cv::String const&, int, cv::String const&)'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:173: undefined reference to `cv::FileStorage::isOpened() const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:176: undefined reference to `cv::FileNode::type() const'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:179: undefined reference to `cv::FileNodeIterator::operator++()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:172: undefined reference to `cv::FileStorage::~FileStorage()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:182: undefined reference to `cv::FileStorage::~FileStorage()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:182: undefined reference to `cv::FileStorage::~FileStorage()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:172: undefined reference to `cv::FileStorage::~FileStorage()'
camera_calibration.o: In function `Settings::~Settings()':
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:28: undefined reference to `cv::VideoCapture::~VideoCapture()'
/home/paradisolab/Desktop/camera_calibration/camera_calibration.cpp:28: undefined reference to `cv::VideoCapture::~VideoCapture()'
camera_calibration.o: In function `cv::Mat::Mat<cv::Point_<float> >(std::vector<cv::Point_<float>, std::allocator<cv::Point_<float> > > const&, bool)':
/usr/local/include/opencv2/core/mat.inl.hpp:484: undefined reference to `cv::Mat::copyTo(cv::_OutputArray const&) const'
camera_calibration.o: In function `cv::Mat::Mat<float>(std::vector<float, std::allocator<float> > const&, bool)':
/usr/local/include/opencv2/core/mat.inl.hpp:484: undefined reference to `cv::Mat::copyTo(cv::_OutputArray const&) const'
collect2: error: ld returned 1 exit status
makefile:9: recipe for target 'camcalib' failed
make: *** [camcalib] Error 1
It seems OpenCV is installed, because when I type "pkg-config --libs --cflags opencv" in terminal, I get:
-I/usr/local/include/opencv -I/usr/local/include -L/usr/local/lib -lopencv_shape -lopencv_stitching -lopencv_objdetect -lopencv_superres -lopencv_videostab -lopencv_calib3d -lopencv_features2d -lopencv_highgui -lopencv_videoio -lopencv_imgcodecs -lopencv_video -lopencv_photo -lopencv_ml -lopencv_imgproc -lopencv_flann -lopencv_viz -lippicv -lopencv_core
I've been trying lots of things, but I'm stumped. If anyone has any advice, I would greatly appreciate it.

C++ - Compilation error with Error class that inherit from std::exception

Here is my Error class to handle errors with try & catch :
#include <stdexcept>
#include <string>
class Error : public std::exception
{
public:
Error(const std::string&) throw();
~Error() throw();
const char* what() const throw();
private:
std::string _msg;
};
And the cpp file :
#include "Error.hpp"
Error::Error(const std::string& msg) throw()
: _msg(msg)
{
}
Error::~Error() throw()
{
}
const char* Error::what() const throw()
{
return (_msg.c_str());
}
And I have this errors while compiling:
main.o:(.gcc_except_table+0x34): undefined reference to `typeinfo for Error'
MailBox.o: In function `MailBox::MailBox(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
MailBox.cpp:(.text+0x245): undefined reference to `Error::Error(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
MailBox.cpp:(.text+0x268): undefined reference to `Error::~Error()'
MailBox.cpp:(.text+0x270): undefined reference to `typeinfo for Error'
MailBox.cpp:(.text+0x2f0): undefined reference to `Error::Error(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
MailBox.cpp:(.text+0x313): undefined reference to `Error::~Error()'
MailBox.cpp:(.text+0x31b): undefined reference to `typeinfo for Error'
MailBox.cpp:(.text+0x3d6): undefined reference to `Error::Error(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
MailBox.cpp:(.text+0x3f9): undefined reference to `Error::~Error()'
MailBox.cpp:(.text+0x401): undefined reference to `typeinfo for Error'
MailBox.cpp:(.text+0x452): undefined reference to `Error::Error(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
MailBox.cpp:(.text+0x475): undefined reference to `Error::~Error()'
MailBox.cpp:(.text+0x47d): undefined reference to `typeinfo for Error'
MailBox.cpp:(.text+0x50a): undefined reference to `Error::Error(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
MailBox.cpp:(.text+0x52d): undefined reference to `Error::~Error()'
MailBox.cpp:(.text+0x535): undefined reference to `typeinfo for Error'
MailBox.cpp:(.text+0x6af): undefined reference to `Error::Error(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
MailBox.cpp:(.text+0x6d2): undefined reference to `Error::~Error()'
MailBox.cpp:(.text+0x6da): undefined reference to `typeinfo for Error'
MailBox.cpp:(.text+0x854): undefined reference to `Error::Error(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
MailBox.cpp:(.text+0x877): undefined reference to `Error::~Error()'
MailBox.cpp:(.text+0x87f): undefined reference to `typeinfo for Error'
MailBox.cpp:(.text+0x923): undefined reference to `Error::Error(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
MailBox.cpp:(.text+0x946): undefined reference to `Error::~Error()'
MailBox.cpp:(.text+0x94e): undefined reference to `typeinfo for Error'
MailBox.cpp:(.text+0x9b6): undefined reference to `Error::Error(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
MailBox.cpp:(.text+0x9d9): undefined reference to `Error::~Error()'
MailBox.cpp:(.text+0x9e1): undefined reference to `typeinfo for Error'
collect2: ld returned 1 exit status
I've already used this Error class for another project, and it worked well. I don't understand why here it doesn't work.
This is not a compilation error, this is a linker error. Basically, this error is informing you that a definition for some your functions is missing.
Reading from the linker's output, it is evident that those functions are the copy constructor and the destructor of class Error.
This is compatible with the fact that you are showing just a declaration of those function (in the class definition for Error). You should also provide a definition for them. For instance, you could simply inline those definitions:
class Error : public std::exception
{
public:
Error(const std::string& s) throw() : _msg(s) { }
~Error() throw() { };
const char* what() const throw() { return _msg.c_str(); };
private:
std::string _msg;
};