问题
I'm trying to make sure serializing works for matrices i.e. Armadillo and I'm getting some errors.
I made a simple example of a random matrix and am trying to save the content using boost in a binary file, then load it using boost:
#include <iostream>
#include <fstream>
#include <boost/archive/tmpdir.hpp>
#include <boost/archive/binary_oarchive.hpp>
#include <boost/archive/binary_iarchive.hpp>
#include <armadillo>
int main() {
arma::mat A = arma::randu<arma::mat>(4,5);
std::ofstream outputStream;
outputStream.open("bin.dat");
std::ostringstream oss;
boost::archive::binary_oarchive oa(outputStream);
oa & A;
outputStream.close(); getting error
arma::mat B;
std::ifstream inputStream;
inputStream.open("bin.dat", std::ifstream::in);
boost::archive::binary_iarchive ia(inputStream);
ia & B;
return 0;
}
I'm getting the following errors (when running the command: g++ -std=c++11 arma_boost.cpp -larmadillo -lboost_serialization
):
In file included from /usr/include/boost/serialization/split_member.hpp:23:0,
from /usr/include/boost/serialization/nvp.hpp:33,
from /usr/include/boost/serialization/array.hpp:19,
from /usr/include/boost/archive/basic_binary_oprimitive.hpp:50,
from /usr/include/boost/archive/binary_oarchive_impl.hpp:22,
from /usr/include/boost/archive/binary_oarchive.hpp:21,
from arma_boost.cpp:4:
/usr/include/boost/serialization/access.hpp: In instantiation of ‘static void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::binary_oarchive; T = arma::Mat<double>]’:
/usr/include/boost/serialization/serialization.hpp:69:69: required from ‘void boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::binary_oarchive; T = arma::Mat<double>]’
/usr/include/boost/serialization/serialization.hpp:128:27: required from ‘void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::archive::binary_oarchive; T = arma::Mat<double>]’
/usr/include/boost/archive/detail/oserializer.hpp:152:5: required from ‘void boost::archive::detail::oserializer<Archive, T>::save_object_data(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::archive::binary_oarchive; T = arma::Mat<double>]’
/usr/include/boost/archive/detail/oserializer.hpp:101:1: required from ‘class boost::archive::detail::oserializer<boost::archive::binary_oarchive, arma::Mat<double> >’
/usr/include/boost/archive/detail/oserializer.hpp:253:13: required from ‘static void boost::archive::detail::save_non_pointer_type<Archive>::save_standard::invoke(Archive&, const T&) [with T = arma::Mat<double>; Archive = boost::archive::binary_oarchive]’
/usr/include/boost/archive/detail/oserializer.hpp:308:28: [ skipping 2 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/boost/archive/detail/common_oarchive.hpp:69:40: required from ‘void boost::archive::detail::common_oarchive<Archive>::save_override(T&, int) [with T = const arma::Mat<double>; Archive = boost::archive::binary_oarchive]’
/usr/include/boost/archive/basic_binary_oarchive.hpp:75:7: required from ‘void boost::archive::basic_binary_oarchive<Archive>::save_override(const T&, int) [with T = arma::Mat<double>; Archive = boost::archive::binary_oarchive]’
/usr/include/boost/archive/binary_oarchive_impl.hpp:51:9: required from ‘void boost::archive::binary_oarchive_impl<Archive, Elem, Tr>::save_override(T&, int) [with T = const arma::Mat<double>; Archive = boost::archive::binary_oarchive; Elem = char; Tr = std::char_traits<char>]’
/usr/include/boost/archive/detail/interface_oarchive.hpp:63:9: required from ‘Archive& boost::archive::detail::interface_oarchive<Archive>::operator<<(T&) [with T = const arma::Mat<double>; Archive = boost::archive::binary_oarchive]’
/usr/include/boost/archive/detail/interface_oarchive.hpp:71:35: required from ‘Archive& boost::archive::detail::interface_oarchive<Archive>::operator&(T&) [with T = arma::Mat<double>; Archive = boost::archive::binary_oarchive]’
arma_boost.cpp:19:6: required from here
/usr/include/boost/serialization/access.hpp:118:9: error: ‘class arma::Mat<double>’ has no member named ‘serialize’
t.serialize(ar, file_version);
^
/usr/include/boost/serialization/access.hpp: In instantiation of ‘static void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::binary_iarchive; T = arma::Mat<double>]’:
/usr/include/boost/serialization/serialization.hpp:69:69: required from ‘void boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::binary_iarchive; T = arma::Mat<double>]’
/usr/include/boost/serialization/serialization.hpp:128:27: required from ‘void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::archive::binary_iarchive; T = arma::Mat<double>]’
/usr/include/boost/archive/detail/iserializer.hpp:192:5: required from ‘void boost::archive::detail::iserializer<Archive, T>::load_object_data(boost::archive::detail::basic_iarchive&, void*, unsigned int) const [with Archive = boost::archive::binary_iarchive; T = arma::Mat<double>]’
/usr/include/boost/archive/detail/iserializer.hpp:120:1: required from ‘class boost::archive::detail::iserializer<boost::archive::binary_iarchive, arma::Mat<double> >’
/usr/include/boost/archive/detail/iserializer.hpp:387:13: required from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::load_standard::invoke(Archive&, const T&) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/detail/iserializer.hpp:439:28: [ skipping 2 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/boost/archive/detail/common_iarchive.hpp:66:40: required from ‘void boost::archive::detail::common_iarchive<Archive>::load_override(T&, int) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/basic_binary_iarchive.hpp:70:7: required from ‘void boost::archive::basic_binary_iarchive<Archive>::load_override(T&, int) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/binary_iarchive_impl.hpp:50:9: required from ‘void boost::archive::binary_iarchive_impl<Archive, Elem, Tr>::load_override(T&, int) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive; Elem = char; Tr = std::char_traits<char>]’
/usr/include/boost/archive/detail/interface_iarchive.hpp:60:9: required from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/detail/interface_iarchive.hpp:67:32: required from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator&(T&) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
arma_boost.cpp:26:6: required from here
/usr/include/boost/serialization/access.hpp:118:9: error: ‘class arma::Mat<double>’ has no member named ‘serialize’
EDIT:
#include <iostream>
#include <fstream>
#include <boost/archive/tmpdir.hpp>
#include <boost/archive/binary_oarchive.hpp>
#include <boost/archive/binary_iarchive.hpp>
#include <armadillo>
namespace boost {
namespace serialization {
template<class Archive>
void serialize(Archive & ar, arma::mat &m, const unsigned int version)
{
ar & m.n_cols;
ar & m.n_rows;
ar & m.n_elem;
}
}
}
int main() {
arma::mat A = arma::randu<arma::mat>(4,5);
std::ofstream outputStream;
outputStream.open("bin.dat");
std::ostringstream oss;
boost::archive::binary_oarchive oa(outputStream);
oa & A;
outputStream.close();
arma::mat b; //tried also arma::mat b(4,5);
std::ifstream inputStream;
inputStream.open("bin.dat", std::ifstream::in);
boost::archive::binary_iarchive ia(inputStream);
ia & b;
return 0;
}
These are the errors I am receiving:
In file included from /usr/include/boost/archive/basic_text_oprimitive.hpp:34:0,
from /usr/include/boost/archive/text_oarchive.hpp:30,
from arma_boost.cpp:3:
/usr/include/boost/archive/detail/check.hpp: In instantiation of ‘void boost::archive::detail::check_const_loading() [with T = const unsigned int]’:
/usr/include/boost/archive/detail/iserializer.hpp:577:38: required from ‘void boost::archive::load(Archive&, T&) [with Archive = boost::archive::binary_iarchive; T = const unsigned int]’
/usr/include/boost/archive/detail/common_iarchive.hpp:66:40: required from ‘void boost::archive::detail::common_iarchive<Archive>::load_override(T&, int) [with T = const unsigned int; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/basic_binary_iarchive.hpp:70:7: required from ‘void boost::archive::basic_binary_iarchive<Archive>::load_override(T&, int) [with T = const unsigned int; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/binary_iarchive_impl.hpp:50:9: required from ‘void boost::archive::binary_iarchive_impl<Archive, Elem, Tr>::load_override(T&, int) [with T = const unsigned int; Archive = boost::archive::binary_iarchive; Elem = char; Tr = std::char_traits<char>]’
/usr/include/boost/archive/detail/interface_iarchive.hpp:60:9: required from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = const unsigned int; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/detail/interface_iarchive.hpp:67:32: [ skipping 8 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/boost/archive/detail/common_iarchive.hpp:66:40: required from ‘void boost::archive::detail::common_iarchive<Archive>::load_override(T&, int) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/basic_binary_iarchive.hpp:70:7: required from ‘void boost::archive::basic_binary_iarchive<Archive>::load_override(T&, int) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/binary_iarchive_impl.hpp:50:9: required from ‘void boost::archive::binary_iarchive_impl<Archive, Elem, Tr>::load_override(T&, int) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive; Elem = char; Tr = std::char_traits<char>]’
/usr/include/boost/archive/detail/interface_iarchive.hpp:60:9: required from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/detail/interface_iarchive.hpp:67:32: required from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator&(T&) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
arma_boost.cpp:54:8: required from here
/usr/include/boost/archive/detail/check.hpp:162:5: error: static assertion failed: typex::value
BOOST_STATIC_ASSERT(typex::value);
^
In file included from /usr/include/boost/archive/binary_iarchive_impl.hpp:21:0,
from /usr/include/boost/archive/binary_iarchive.hpp:20,
from arma_boost.cpp:11:
/usr/include/boost/archive/basic_binary_iprimitive.hpp: In instantiation of ‘void boost::archive::basic_binary_iprimitive<Archive, Elem, Tr>::load(T&) [with T = const unsigned int; Archive = boost::archive::binary_iarchive; Elem = char; Tr = std::char_traits<char>]’:
/usr/include/boost/archive/detail/iserializer.hpp:107:9: required from ‘static void boost::archive::load_access::load_primitive(Archive&, T&) [with Archive = boost::archive::binary_iarchive; T = const unsigned int]’
/usr/include/boost/archive/detail/iserializer.hpp:362:46: required from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::load_primitive::invoke(Archive&, T&) [with T = const unsigned int; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/detail/iserializer.hpp:439:28: required from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::invoke(Archive&, T&) [with T = const unsigned int; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/detail/iserializer.hpp:592:24: required from ‘void boost::archive::load(Archive&, T&) [with Archive = boost::archive::binary_iarchive; T = const unsigned int]’
/usr/include/boost/archive/detail/common_iarchive.hpp:66:40: required from ‘void boost::archive::detail::common_iarchive<Archive>::load_override(T&, int) [with T = const unsigned int; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/basic_binary_iarchive.hpp:70:7: [ skipping 11 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/boost/archive/detail/common_iarchive.hpp:66:40: required from ‘void boost::archive::detail::common_iarchive<Archive>::load_override(T&, int) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/basic_binary_iarchive.hpp:70:7: required from ‘void boost::archive::basic_binary_iarchive<Archive>::load_override(T&, int) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/binary_iarchive_impl.hpp:50:9: required from ‘void boost::archive::binary_iarchive_impl<Archive, Elem, Tr>::load_override(T&, int) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive; Elem = char; Tr = std::char_traits<char>]’
/usr/include/boost/archive/detail/interface_iarchive.hpp:60:9: required from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
/usr/include/boost/archive/detail/interface_iarchive.hpp:67:32: required from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator&(T&) [with T = arma::Mat<double>; Archive = boost::archive::binary_iarchive]’
arma_boost.cpp:54:8: required from here
/usr/include/boost/archive/basic_binary_iprimitive.hpp:88:35: error: invalid conversion from ‘const void*’ to ‘void*’ [-fpermissive]
load_binary(& t, sizeof(T));
^
/usr/include/boost/archive/basic_binary_iprimitive.hpp:149:1: note: initializing argument 1 of ‘void boost::archive::basic_binary_iprimitive<Archive, Elem, Tr>::load_binary(void*, std::size_t) [with Archive = boost::archive::binary_iarchive; Elem = char; Tr = std::char_traits<char>; std::size_t = long unsigned int]’
basic_binary_iprimitive<Archive, Elem, Tr>::load_binary(
^
回答1:
Armadillo provides a way to save its type to an HDF5 file that works well and might be enough for you.
Armadillo has no support to boost serialization. From boost serialization tutorial we can see that a class must have a serialize method to be serializable with boost. Armadillo has no such method and that is the error you get.
Alternatively, boost also allows a non-intrusive way to make a class work with it, which involves implementing a serialize free function. Since all you need is the elements in a matrix and its dimension that should be easy to implement following the boost serialization tutorial.
Edit after the question was edited.
The error you are getting is indeed hard to pinpoint the reason at first, but if you comment the line with the loading part (last line before the return) you will see that it compiles just fine. If you ran the executable the binary file will be created and thus the serialization part is working (but remember the serialize function in your question is not serializing the elements yet).
Now let's go back to the error
/usr/include/boost/archive/basic_binary_iprimitive.hpp:88:35: error: invalid conversion from ‘const void*’ to ‘void*’ [-fpermissive]
load_binary(& t, sizeof(T));
There is some const type (erased by boost and thus you get void *) that should not be const. If we have another look into the serialize template function and the tutorial we can see that it is used for both serialization and loading, although in each case Archive type is different. That means that in the code below
ar & m.n_cols;
ar & m.n_rows;
ar & m.n_elem;
during the serialization, the values are read from m (OK). However, during the loading the values are written to m, which is not OK since these are constant attributes. That is the problem. In order to fix this you need to split the save and load into separate functions. Then, in the load implementation, you can use one of the armadillo constructors to create a new matrix from the loaded data. The easiest way to do this is to remove the template and create two overloads for the serialize function
// This is the saving part
void serialize(boost::archive::binary_oarchive &ar, arma::mat &m,
const unsigned int version) {
ar &m.n_cols;
ar &m.n_rows;
ar &m.n_elem; // You don't really need this one
// Note: You must also serialize the elements, which is currently missing
}
// This is the loading part
void serialize(boost::archive::binary_iarchive &ar, arma::mat &m,
const unsigned int version) {
// use one of the suitable constructors here
m = arma::mat( ... )
}
A possible full implementation of both serialize overloads is shown below (I have tested them by printing both A and B matrices and they are the same). The most important thing to remember is that you must read the values in the same order you save them.
void serialize(boost::archive::binary_oarchive &ar, arma::mat &m,
const unsigned int version) {
// Since this is used only for reading I prefer the "<<" symbol instead of
// "&", but "&" would work just fine
ar << m.n_cols;
ar << m.n_rows;
// Loop to save each element in order
for (unsigned i = 0; i < m.n_elem; i++) {
// memptr gives us a pointer to the raw memory used to store the elements
ar << m.memptr()[i];
}
}
void serialize(boost::archive::binary_iarchive &ar, arma::mat &m,
const unsigned int version) {
arma::uword n_cols;
arma::uword n_rows;
ar >> n_cols;
ar >> n_rows;
m = arma::mat(n_rows, n_cols);
// Loop to read each element in order
for (unsigned i = 0; i < m.n_elem; i++) {
ar >> m.memptr()[i];
}
}
Disclaimer: I actually had never used boost serialization before and thus there might be a better way to do this.
来源：https://stackoverflow.com/questions/60633451/boost-serializing-armadillo-matrices