I am having some issues using the unordered map below:
unordered_map<string, vector<string>> FriendHash;
When I compile my code I get the following errors:
usr/lib/c++/v1/type_traits:922:38: Implicit instantiation of undefined template 'std::__1::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >'
usr/lib/c++/v1/unordered_map:360:71: No member named 'value' in 'std::__1::is_empty<std::__1::hash<std::__1::basic_string<char> > >'
Hoping someone can point me in the right direction.
Whatever you use needs to be defined. You need to include string here possibly along with other dependencies.
#include <string>
Related
I'm using templates while implementing AVL trees on Ubuntu.
The file will not compile when I write template class AVLTree<std::list<int> >;, it tells me:
undefined reference to `AVLTree < std::__cxx11::list < 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> > > > >::insert(std::__cxx11::basic_string < char, std::char_traits < char>, std::allocator < char> >)'
And I don't get what it doesn't have the reference to.
But it compiles just fine when I write template class AVLTree<std::list<string> >;
I need to let AVLTree store linked lists that store string values.
Why does one compile and the other doesn't? How to solve my problem?
PS: I've included <list>, <string>, and <iostream>, along with my own header file.
Examining the error message closely shows that linker cannot find the AVLTree::insert(string) method.
Based on the sparse information that you posted, my best hypothesis is that you changed the template parameter in the following line from list<string> to list<int>:
template class AVLTree<std::list<string>>;
This line of code explicitly tells the compiler to instantiate a version of the AVLTree template using list<string> as the template parameter. Thus, when you try to compile the code after the change it gives you the error message that it cannot find the AVLTree::insert(string) function because the compiler is now generating the code for list<int> instead.
Your program contains other code that is referencing AVLTree<list<string>>. At a minimum you will have to update that code to use list<int> as well.
Plus, if you simplify the problem down to something you can post the code for on this site, then you will either find the issue during that process or at least have a change of getting a good answer.
I had a problem when using Eclipse CDT with detecting stl information. I got in-editor errors like "symbol vector could not be resolved". I have solved this using the solution described here:
https://stackoverflow.com/a/13524483/613173
However, it seems that stl::map still has problems. For example, the line
std::map<int,int> a;
Gets the "invalid template arguments" error. Also,
a.begin();
Gives "method 'begin' could not be resolved" error.
However, with default parameters given explicitly:
std::map<int, int, std::less<int>, std::allocator<std::pair<const int, int> > > b;
I got none of those errors. This does not happen with other classes such as std::vector whose template also has more than one argument but I get no complaints over
std::vector<int> a;
Another problem regards iterators. Even if the map was defined with all parameters given explicitly, the "first" and "second" fields give an error:
std::map<int, int, std::less<int>, std::allocator<std::pair<const int, int> > >::iterator i_b = b.begin();
i_b->first;
This gives "Field 'first' could not be resolved".
Compilation works without problems, obviously, but I still want to be able to use Eclipse's static error detection and auto completion.
Eclipse 4.4.2, CDT 8.6.
I have a C++ program that uses the CGAL 4.5.2_0 library, installed using macports. Recently, I have been getting compile-time warnings that the CGAL/AABB_polyhedron_triangle_primitive.h header is deprecated and that I now should start using CGAL/AABB_face_graph_triangle_primitive.h, so I naively switched the header name and also added the CGAL/boost/graph/graph_traits_Polyhedron_3.h header file which now seems to be necessary to interface with the Boost Graph Library. I noticed also from examples in the CGAL documentation that one of my typedefs needed to be updated from
typedef CGAL::AABB_polyhedron_triangle_primitive<K,Polyhedron> Primitive;
to
typedef CGAL::AABB_face_graph_triangle_primitive<Polyhedron> Primitive;
And so far, that is the extent of what I have done. But now I am getting two new errors at compile time:
In file included from ./Particle.h:44:
/opt/local/include/CGAL/AABB_tree.h:810:27: error: no matching conversion for functional-style cast from 'CGAL::internal::In_place_list_iterator<CGAL::HalfedgeDS_in_place_list_face<CGAL::I_Polyhedron_facet<My_facet<CGAL::HalfedgeDS_list_types<CGAL::Epick, CGAL::I_Polyhedron_derived_items_3<My_items>, std::__1::allocator<int> >, CGAL::Boolean_tag<true>, CGAL::Vector_3<CGAL::Epick> > > >, std::__1::allocator<CGAL::HalfedgeDS_in_place_list_face<CGAL::I_Polyhedron_facet<My_facet<CGAL::HalfedgeDS_list_types<CGAL::Epick, CGAL::I_Polyhedron_derived_items_3<My_items>, std::__1::allocator<int> >, CGAL::Boolean_tag<true>, CGAL::Vector_3<CGAL::Epick> > > > > >' to 'Primitive' (aka 'CGAL::AABB_face_graph_triangle_primitive<CGAL::Polyhedron_3<CGAL::Epick, My_items, HalfedgeDS_default, std::__1::allocator<int> >, CGAL::Default, CGAL::Boolean_tag<true>, CGAL::Boolean_tag<false> >')
m_primitives.push_back(Primitive(first));
In file included from ./Particle.h:45:
/opt/local/include/CGAL/AABB_traits.h:63:33: error: no matching member function for call to 'construct_shared_data'
m_primitive_data=Primitive::construct_shared_data();
~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
/opt/local/include/CGAL/AABB_tree.h:268:15: note: in instantiation of member function 'CGAL::internal::AABB_tree::AABB_traits_base<CGAL::AABB_face_graph_triangle_primitive<CGAL::Polyhedron_3<CGAL::Epick, My_items, HalfedgeDS_default, std::__1::allocator<int> >, CGAL::Default, CGAL::Boolean_tag<true>, CGAL::Boolean_tag<false> >, true>::set_shared_data' requested here
{m_traits.set_shared_data();}
^
If anyone has experience switching from the deprecated header file to the new one, I will be grateful for any advice you might have about how I should proceed.
I can post the header file for the Particle class that seems to be the problem, but it is 3282 lines long and I'm not sure which part(s) I should post.
In response to comment, here is the code that is used to insert primitives in the tree:
// The next chunk creates the 3D polyhedron, storing it in surface_poly
Polyhedron surface_poly = getSurfacePolyhedronFromImage(fname,centroid,xBB,yBB,zBB);
// First translate its centroid to the origin
// CartesianVector is a typedef of CGAL's Vector_3
const CartesianVector translation_vector(-centroid[0],-centroid[1],-centroid[2]);
Aff_transformation_3 transl(CGAL::TRANSLATION, translation_vector);
transform(surface_poly.points_begin(),surface_poly.points_end(),
surface_poly.points_begin(),transl);
// Now the centroid is the origin
centroid.resize(3,0.0);
CartesianPoint origin(0.0,0.0,0.0);
// Construct the AABB tree for quick intersection queries
cout << "Creating AABB tree from polyhedron" << endl;
cout.flush();
Tree tree(surface_poly.facets_begin(),surface_poly.facets_end());
// Object intersection will hold the point of intersection with the surface
boost::optional<Object_and_primitive_id> intersection;
The syntax for the Tree constructor is incorrect for the Polyhedron_3 in the code above. The correct syntax should be
Tree tree(faces(surface_poly).first, faces(surface_poly).second, surface_poly);
Updating the syntax to the correct form fixes the compile-time errors.
I'm trying to compile the Statemachine example from boost-mpl (located in libs/mpl/examples/fsm/player2.cpp), but it fails with boost version 1.37 and g++ 4.8.2. With boost version 1.56 and the same compiler, the build succeeds. Unfortunately, due to some platform constraints, I cannot switch to version 1.56.
I'm not expecting anyone to look into the above mentioned lengthy example, therefore I identified a minimal code snippet which illustrates the problem:
#include <boost/mpl/fold.hpp>
#include <boost/mpl/vector.hpp>
#include <boost/mpl/placeholders.hpp>
namespace mpl = boost::mpl;
using namespace mpl::placeholders;
//Basic queue datatype
template< class CURRENT, class NEXT >
struct queue_element
{
typedef typename CURRENT::mytype mytype;
};
//type to be put at the end of the queue
struct default_queue_element
{
};
template <class TYPE>
struct wrapper{
typedef TYPE mytype;
};
typedef mpl::vector<wrapper<int>, wrapper<char> > myvector;
//the following fold expression should create this type:
typedef queue_element<wrapper<char>, queue_element<wrapper<int>,
default_queue_element> > this_type_should_be_created;
//This typedef fails to compile with boost Version 1.37,
//but works perfectly with version 1.56
typedef typename
mpl::fold<
myvector
,default_queue_element
,queue_element<_2,_1>
>::type
generate_queue;
With boost 1.37, g++ issues the following errors:
foldtest2.cpp: In instantiation of ‘struct queue_element<mpl_::arg<2>, mpl_::arg<1> >’:
../boost_1_37_0/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp:85:5: required from ‘const int boost::mpl::aux::template_arity_impl<queue_element<mpl_::arg<2>, mpl_::arg<1> >, 1>::value’
../boost_1_37_0/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp:93:5: required from ‘const int boost::mpl::aux::template_arity<queue_element<mpl_::arg<2>, mpl_::arg<1> > >::value’
../boost_1_37_0/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp:98:30: required from ‘struct boost::mpl::aux::template_arity<queue_element<mpl_::arg<2>, mpl_::arg<1> > >’
../boost_1_37_0/boost/mpl/aux_/preprocessed/gcc/apply.hpp:67:8: required from ‘struct boost::mpl::apply2<queue_element<mpl_::arg<2>, mpl_::arg<1> >, default_queue_element, wrapper<int> >’
../boost_1_37_0/boost/mpl/aux_/preprocessed/gcc/fold_impl.hpp:67:85: required from ‘struct boost::mpl::aux::fold_impl<2, boost::mpl::v_iter<boost::mpl::vector<wrapper<int>, wrapper<char> >, 0l>, boost::mpl::v_iter<boost::mpl::vector<wrapper<int>, wrapper<char> >, 2l>, default_queue_element, queue_element<mpl_::arg<2>, mpl_::arg<1> > >’
../boost_1_37_0/boost/mpl/fold.hpp:39:18: required from ‘struct boost::mpl::fold<boost::mpl::vector<wrapper<int>, wrapper<char> >, default_queue_element, queue_element<mpl_::arg<2>, mpl_::arg<1> > >’
foldtest2.cpp:39:6: required from here
foldtest2.cpp:15:38: error: no type named ‘mytype’ in ‘struct mpl_::arg<2>’
typedef typename CURRENT::mytype mytype;
Is there a work-around to make the code compile with boost 1.37? I have been searching the web for quite some time. If nevertheless the question has already been answered somewhere, I would be grateful if you could point that out.
Looks to be very simply a bug in that ancient(¹) version of boost.
A quick bisection tells me it was fixed in v1.43.0(²). Release notes don't disclose the secret, but git does:
c5621d9 MPL: merge fix for ticket #1992 boost::mpl::zip_view does not support use as a metafunction with ::type
31a2c78 MPL: merge fix for ticket #4061 [MPL] gcc-4.5 compilation problems related to arity_helper
It clearly appears to be the latter (confirmed by compiling against 31a2c78).
So your fix this single line in include/boost/mpl/aux_/template_arity.hpp(³):
sizeof(arity_helper(type_wrapper<F>(),arity_tag<N>())) - 1
should be
sizeof(::boost::mpl::aux::arity_helper(type_wrapper<F>(),arity_tag<N>())) - 1
Of course the proper way to fix this is to use a supported version of boost
¹ (November 3rd, 2008)!!
² (May 6th, 2010)
³ warning: also present in several copies generated in preprocessed versions of the header
How to generate fusion::vector from mpl::vector?
How to generate mpl::vector from fusion::vector?
BOOST_MPL_ASSERT((is_same<
fusion::vector<int, char>,
generate_fusion_vector<mpl::vector<int, char> >::type >));
BOOST_MPL_ASSERT((is_same<
mpl::vector<int, char>,
generate_mpl_vector<fusion::vector<int, char> >::type >));
I need generate_fusion_vector and generate_mpl_vector metafunctions.
I can write my own metafunctions, but i suspect that they already exist.
I had an experience of generating fusion::map with help result_of::as_map before, but in current boost(trunk, 1.39 also) such error occur:
D:\Libraries\boost_trunk\boost/fusion/sequence/intrinsic/size.hpp(56) : error C2903: 'apply' : symbol is neither a class template nor a function template
D:\Libraries\boost_trunk\boost/fusion/container/vector/convert.hpp(23) : see reference to class template instantiation 'boost::fusion::result_of::size' being compiled
with
[
Sequence=boost::mpl::vector
]
temp.cpp(71) : see reference to class template instantiation 'boost::fusion::result_of::as_vector' being compiled
I don't understand what is going on?
As fusion accepts mpl types as arguments to functions you could try this:
BOOST_MPL_ASSERT((is_same<
fusion::vector<int, char>,
fusion::result_of::as_vector<mpl::vector<int, char> >::type >));
Edit:
I think the reason this isn't working for you is that you have to include certain header files to enable mpl compatibility in fusion.
#include <boost/fusion/adapted/mpl.hpp>
#include <boost/fusion/include/mpl.hpp>
I don't know if you're still doing char,int but I ran into the same error and my problem was that I tried to make a length 11 vector, but FUSION_MAX_VECTOR_SIZE was 10.