Problems compiling Boost::Python - c++

I want to use c++ numerical recipes on my python script but I am having some issues compiling some stuff in the Boost Python Libraries. Specificly I want to expose the amoeba function to python. I use Make rather than BJam. This is what I get when I try to compile:
costantinoagnesi#costantino-HP-Pavilion-dv5-Notebook-PC:~/Desktop/Boost Python Test$ make
g++ -I/usr/include/python2.7 -I/usr/include -fPIC -c amoeba_py.C
In file included from /usr/local/include/boost/python/object/make_instance.hpp:10:0,
from /usr/local/include/boost/python/object/make_ptr_instance.hpp:8,
from /usr/local/include/boost/python/to_python_indirect.hpp:11,
from /usr/local/include/boost/python/converter/arg_to_python.hpp:10,
from /usr/local/include/boost/python/call.hpp:15,
from /usr/local/include/boost/python/object_core.hpp:14,
from /usr/local/include/boost/python/args.hpp:25,
from /usr/local/include/boost/python.hpp:11,
from amoeba_py.C:73:
/usr/local/include/boost/python/converter/registered.hpp: In function ‘const boost::python::converter::registration&
boost::python::converter::detail::registry_lookup2(T& (*)()) [with T = double(const NRVec<double>&)]’:
/usr/local/include/boost/python/converter/registered.hpp:94:40: instantiated from ‘const >boost::python::converter::registration& boost::python::converter::detail::registry_lookup1(boost::type<T>) [with T = double (&)(const NRVec<double>&)]’
/usr/local/include/boost/python/converter/registered.hpp:105:23: instantiated from const boost::python::converter::registration& boost::python::converter::detail::registered_base<double (&)(const NRVec<double>&)>::converters’
/usr/local/include/boost/python/converter/arg_from_python.hpp:269:99: instantiated from ‘boost::python::converter::pointer_arg_from_python<T>::pointer_arg_from_python(PyObject*) [with T = double (*)(const NRVec<double>&), PyObject = _object]’
/usr/local/include/boost/python/arg_from_python.hpp:70:18: instantiated from ‘boost::python::arg_from_python<T>::arg_from_python(PyObject*) [with T = double (*)(const NRVec<double>&), PyObject = _object]’
/usr/local/include/boost/preprocessor/iteration/detail/local.hpp:43:1: instantiated from >‘PyObject* boost::python::detail::caller_arity<5u>::impl<F, Policies, Sig>::operator( (PyObject*, PyObject*) [with F = void (*)(NRMat<double>&, NRVec<double>&, double, double (*)(const NRVec<double>&), int&), Policies = boost::python::default_call_policies, Sig = boost::mpl::vector6<void, NRMat<double>&, NRVec<double>&, double, double (*)(const NRVec<double>&), int&>, PyObject = _object]’
/usr/local/include/boost/python/object/py_function.hpp:38:33: instantiated from ‘PyObject* boost::python::objects::caller_py_function_impl<Caller>::operator()(PyObject*, PyObject*) [with Caller = boost::python::detail::caller<void (*)(NRMat<double>&, NRVec<double>&, double, double (*)(const NRVec<double>&), int&), boost::python::default_call_policies, boost::mpl::vector6<void, NRMat<double>&, NRVec<double>&, double, double (*)(const NRVec<double>&), int&> >, PyObject = _object]’ amoeba_py.C:79:1: instantiated from here
/usr/local/include/boost/python/converter/registered.hpp:86:7: error: no matching function >for call to ‘register_shared_ptr1(double (*)(const NRVec<double>&))’
/usr/local/include/boost/python/converter/registered.hpp:86:7: note: candidate is:
/usr/local/include/boost/python/converter/registered.hpp:77:3: note: template<class T> void boost::python::converter::detail::register_shared_ptr1(const volatile T*)
make: *** [amoeba_py.o] Error 1
Can someone help me decipher what this error means and perhaps give me some helpful tip to finish my project. It's worth noting that the classic Boost Python example compiles just fine.
Thank you!
Here's the offending text: (lines 73-79)
#include <boost/python.hpp>
using namespace boost::python;
BOOST_PYTHON_MODULE(amoeba)
{
def("amoeba", NR::amoeba);
}

I suspect you're having a similar problem to the guy who asked this question. Are you passing a function pointer as an argument in your C++ code? If so, you can't do that in Python -- see the answer as to why.

You forgot reference operator. Thus the def is getting parameter type double (*)(const NRVec<double>&) instead of const volatile T* it expects.
Your code ought to look like this:
BOOST_PYTHON_MODULE(amoeba)
{
def("amoeba", &NR::amoeba);
}

Related

declaring / compiling 2d vector of vectors

A colleague has provided me with a package of c++ code based on some Celestrak satellite code https://celestrak.org/software/vallado/cpp.zip.
In several places the code, i.e coordfk5.cpp declares vectors of vectors like
std::vector< std::vector<double> > prec, nut(3,3), st, stdot, pm, pmp
The nut(3,3) and similar declarations won't compile on my system yet does for the colleague on his and presumably others who have downloaded the original package.
stl_vector.h: In instantiation of 'void std::vector<_Tp, _Alloc>::_M_initialize_dispatch(_Integer, _Integer, std::__true_type) [with _Integer = int; _Tp = std::vector; _Alloc = std::allocatorstd::vector<double >]':
stl_vector.h:404:55: required from 'std::vector<_Tp, _Alloc>::vector(_InputIterator, _InputIterator, const allocator_type&) [with _InputIterator = int; _Tp = std::vector; _Alloc = std::allocatorstd::vector<double >; std::vector<_Tp, _Alloc>::allocator_type = std::allocatorstd::vector<double >]'
stl_vector.h:1166:59: error: no matching function for call to 'std::vectorstd::vector<double >::_M_fill_initialize(std::vectorstd::vector<double >::size_type, int&)'
_M_fill_initialize(static_cast<size_type>(__n), __value);
I'm on gcc version 4.8.1, the colleague is on 4.6.3. I've tried adding -std=c++98 etc options to no avail.
I can get the code to compile by changing to eg
nut(3,std::vector<double>(3))
but not sure if this is right as the code then seg faults.
So two questions,
Is it possible with some options/switches to compile the code as is?
If not any idea how these vectors should be declared and set-up?
The nut(3,3) attempts to use 3 as initializer for the inner std::vector<int>.
However, std::vector has an explicit constructor which is why it doesn't compile. As you have found, explicit constructors have to have the type explicitly written, with nut(3, std::vector<int>(3)).
Some older compilers came with a vector that didn't mark the constructor as explicit which would explain your colleagues' observations.

what is the reason behind vector's push_back error

I have a simple c++ std::vector and inside it, i am storing threads as shown below. Can you please explain why the line with comment "does not compile" shows error during compilation? And why the line with comment "compiles" work?
#include<thread>
#include<vector>
using namespace std;
void abc() {}
int main()
{
vector<thread> workers;
workers.push_back(thread(abc)); // compiles
thread t(abc);
workers.push_back(t); // does not compile
return 0;
}
UPDATE: i am using g++ 4.4.6 on linux. Below is the error
[jim#cola c++]$ g++ -std=c++0x -pthread -g -Wall t.cpp -o t
In file included from /usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/x86_64-redhat-linux/bits/c++allocator.h:34,
from /usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/bits/allocator.h:48,
from /usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/string:43,
from /usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/bits/locale_classes.h:42,
from /usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/bits/ios_base.h:43,
from /usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/ios:43,
from /usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/ostream:40,
from /usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/iostream:40,
from t.cpp:1:
/usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/thread: In member function ‘void __gnu_cxx::new_allocator<_Tp>::construct(_Tp*, const _Tp&) [with _Tp = std::thread]’:
/usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/bits/stl_vector.h:737: instantiated from ‘void std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = std::thread, _Alloc = std::allocator<std::thread>]’
t.cpp:29: instantiated from here
/usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/thread:122: error: deleted function ‘std::thread::thread(const std::thread&)’
/usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/ext/new_allocator.h:105: error: used here
In file included from /usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/vector:69,
from t.cpp:4:
/usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/thread: In member function ‘void std::vector<_Tp, _Alloc>::_M_insert_aux(__gnu_cxx::__normal_iterator<typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::pointer, std::vector<_Tp, _Alloc> >, _Args&& ...) [with _Args = const std::thread&, _Tp = std::thread, _Alloc = std::allocator<std::thread>]’:
/usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/bits/stl_vector.h:741: instantiated from ‘void std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = std::thread, _Alloc = std::allocator<std::thread>]’
t.cpp:29: instantiated from here
/usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/thread:122: error: deleted function ‘std::thread::thread(const std::thread&)’
/usr/lib/gcc/x86_64-redhat-linux/4.4.6/../../../../include/c++/4.4.6/bits/vector.tcc:314: error: used here
You're getting the error because std::thread is noncopyable, and you're trying to insert a copy of t into the vector.
The only way you could make this work would be to do:
workers.push_back(std::move(t));
However, this would mean that after you do that, t no longer represents a thread (the thread it represented was moved into the vector).
The reason is that std::thread has a move constructor, but doesn't have a copy constructor.
Here is a cleaner and faster solution that requires neither copying nor moving:
workers.emplace_back(abc);
Because std::thread is not copyable, you could move it to vector though:
thread t(abc);
workers.push_back(std::move(t));
Better solution is to store smart pointer in vector:
std::vector<std::shared_ptr<std::thread>> workers;
Because when work with lambda, there is no way to capture a move only type, a workaround is to store a move-only type in std::shared_ptr<std::thread>.

filesystem::path constructor call fails

This code does not compile, using Boost 1.48 and GCC:
// const char* left, const char* right
boost::filesystem::path p = boost::filesystem::absolute(
boost::filesystem::path(right, boost::filesystem::native), // line 314
boost::filesystem::path(left, boost::filesystem::native) ); // line 315
Error messages:
LoggerImplementation.cpp|314|error: invalid conversion from ‘bool (*)(const std::string&)’ to ‘void*’
LoggerImplementation.cpp|314|error: initializing argument 2 of ‘boost::filesystem3::path::path(const Source&, typename boost::enable_if<boost::filesystem3::path_traits::is_pathable<typename boost::decay<Source>::type>, void>::type*) [with Source = const char*]’
LoggerImplementation.cpp|315|error: invalid conversion from ‘bool (*)(const std::string&)’ to ‘void*’
LoggerImplementation.cpp|315|error: initializing argument 2 of ‘boost::filesystem3::path::path(const Source&, typename boost::enable_if<boost::filesystem3::path_traits::is_pathable<typename boost::decay<Source>::type>, void>::type*) [with Source = const char*]’
Under MSVC it compiles. How can I fix this?
Your second argument (boost::filesystem::native) is wrong. boost::filesystem::path simply doesn’t have a constructor which takes this argument – leave it off and the code compiles.
In fact, boost::filesystem::native is a function, and using it in the manner you tried makes no sense. Furthermore, if MSVC compiles this code, that’s a definitive bug (it is using an implicit conversion from a function pointer to void*, which doesn’t exist according to the standard).

Boost serialization and namespace

I'm new using Boost serialization. I'm using xml serialization and the non intrusive version. I followed the tutorial (from Boost website) step by step and my code works fine.
The problem arise when I put my class (the code is divided in .h and .cpp plus a main.cpp file) in a namespace (ns_mytests). In this case the compiler (g++) complains and I have the following errors:
g++ -c -g test.o.d -o build/Debug/GNU-Linux-x86/sources/test.o sources/test.cpp
/opt/local/include/boost/serialization/split_free.hpp: In static member function 'static void boost::serialization::free_saver<Archive, T>::invoke(Archive&, const T&, unsigned int) [with Archive = boost::archive::xml_oarchive, T = ns_mytests::Test]':
/opt/local/include/boost/serialization/split_free.hpp:74: instantiated from 'void boost::serialization::split_free(Archive&, T&, unsigned int) [with Archive = boost::archive::xml_oarchive, T = ns_mytests::Test]'
sources/test.h:117: instantiated from 'void boost::serialization::serialize(Archive&, ns_mytests::Test&, unsigned int) [with Archive = boost::archive::xml_oarchive]'
/opt/local/include/boost/serialization/serialization.hpp:128: instantiated from 'void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::archive::xml_oarchive, T = ns_mytests::Test]'
/opt/local/include/boost/archive/detail/oserializer.hpp:148: instantiated from 'void boost::archive::detail::oserializer<Archive, T>::save_object_data(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::archive::xml_oarchive, T = ns_mytests::Test]'
sources/test.cpp:146: instantiated from here
/opt/local/include/boost/serialization/split_free.hpp:45: error: no matching function for call to 'save(boost::archive::xml_oarchive&, const ns_mytests::Test&, const boost::serialization::version_type&)'
make[2]: *** [build/Debug/GNU-Linux-x86/sources/test.o] Error 1
make[1]: *** [.build-conf] Error 2
make: *** [.build-impl] Error 2
It's sure that I'm doing wrong something, but I could't find my error.
Any help is appreciated.
Thanks,
westfork
Define the non-intrusive save in the namespace where the type to be serialized is defined.

make_shared create std::shared_ptr? gcc 4.6.2

i'm using gcc 4.6.2.
I'm trying to push_back in a vector shared_ptr's.
But gcc gives me everytime an error.
Here my codelines:
std::vector< std::tr1::shared_ptr<Process> > procs;
std::string line;
while (getline(file, line) && line.find(JobMask) != std::string::npos)
{
std::string procName = line.substr(line.find(JobMask) + JobMask.size());
std::vector<Instruction> procInstructions = extractProgram(file);
std::queue<int> procInputs = extractInputs(file);
if (!procInstructions.empty())
procs.push_back(std::make_shared<Process>(Process(procName, procInputs, procInstructions))); //line 51
}
return procs;
The Error my gcc is giving is:
Process.cpp: In static member function 'static std::vector<std::tr1::shared_ptr<RMMIX::Process> > RMMIX::Process::createProcesses(const string&)':
Process.cpp:51:95: error: no matching function for call to 'std::vector<std::tr1::shared_ptr<RMMIX::Process> >::push_back(std::shared_ptr<RMMIX::Process>)'
Process.cpp:51:95: note: candidates are:
/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.2/include/g++-v4/bits/stl_vector.h:826:7: note: void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = std::tr1::shared_ptr<RMMIX::Process>, _Alloc = std::allocator<std::tr1::shared_ptr<RMMIX::Process> >, std::vector<_Tp, _Alloc>::value_type = std::tr1::shared_ptr<RMMIX::Process>]
/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.2/include/g++-v4/bits/stl_vector.h:826:7: note: no known conversion for argument 1 from 'std::shared_ptr<RMMIX::Process>' to 'const value_type& {aka const std::tr1::shared_ptr<RMMIX::Process>&}'
/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.2/include/g++-v4/bits/stl_vector.h:839:7: note: void std::vector<_Tp, _Alloc>::push_back(std::vector<_Tp, _Alloc>::value_type&&) [with _Tp = std::tr1::shared_ptr<RMMIX::Process>, _Alloc = std::allocator<std::tr1::shared_ptr<RMMIX::Process> >, std::vector<_Tp, _Alloc>::value_type = std::tr1::shared_ptr<RMMIX::Process>]
/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.2/include/g++-v4/bits/stl_vector.h:839:7: note: no known conversion for argument 1 from 'std::shared_ptr<RMMIX::Process>' to 'std::vector<std::tr1::shared_ptr<RMMIX::Process> >::value_type&& {aka std::tr1::shared_ptr<RMMIX::Process>&&}'
In my eyes the error say's, that std::make_shared create a std::shared_ptr.
But in gcc shared_ptr is in the namespace std::tr1.
How could i fix it?
If I understand correctly, make_shared is new in C++11 and is in namespace std, but it is only available if you compile with -std=gnu++0x or similar. But if you do that, then shared_ptr is also in std.
The problem is that there is another version of shared_ptr in std::tr1, but in C++11 mode you should not use it: it should be considered deprecated.
Your solution is simply to remove every use of tr1 and use the full C++11 version of these classes.
C++ template error message can be a beast to read. But the answer is in the 2nd note.
no known conversion for argument 1 from 'std::shared_ptr<RMMIX::Process>' to 'const value_type& {aka const std::tr1::shared_ptr<RMMIX::Process>&}'
The problem is you're using std::make_shared (which creates a std::shared_ptr) and passing it into a vector of std::tr1::shared_ptr.
The simplest solution is drop the TR1. The stuff from the TR1 was some of first features implemented by compilers when adding C++11 support.
std::vector< std::shared_ptr<Process> > procs;
If you are unable to stop using std::tr1::shared_ptr. You'll have to forgo using make_shared as it was not part of the TR1.