Re: [Boost-users] [vector, PropertyGraph] Problem declaring a class member of the "vector<int>" type

Subject: Re: [Boost-users] [vector, PropertyGraph] Problem declaring a class member of the "vector<int>" type
From: Philipp Moeller (philipp.moeller_at_[hidden])
Date: 2012-03-09 17:47:40

Alex Sadovsky <a_sadovsky_at_[hidden]> writes:

> Hello everyone,
>>
>>I am trying to declare, in a header file, a class that has a member
>> of type "vector<double>" (the code is included below). ?The compiler
>> complains that I haven't included the appropriate namespace (the
>> error message reads, "ISO C++ forbids declaration of ?vector? with
>> no type"), and I understand that it is looking for this:
>>
>>using namespace boost::numeric::ublas;
>>
>>However, I tried putting it in the header file in various places
>> (haven't programmed in C++ in 10 years and couldn't find any online
>> documentation to clarify this specific situation), and still no
>> luck. ?I am definitely doing something wrong, but cannot reason out
>> the error, as it probably has to do with the specific syntax
>> conventions. ?Any help is appreciated!
>>
>>Thanks,
>>-Al
>>
>>P.S. ?Code in header file:
>>
>>//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
>>// ?File "airspace-graph-rectilinear-edges.h"
>>typedef char* string;
>>const int PHYSICAL_SPACE_DIMENSION = 2;
>>// ?Information needed about a waypoint used in an airspace: name and physical position
>>class WaypointConcept{
>>?private:
>>??using namespace boost::numeric::ublas;
>>??string waypoint_name;
>>??vector<double> waypoint_position_xyh(PHYSICAL_SPACE_DIMENSION);
>>?public:
>>??string GetWaypointName();
>>??vector<double> GetWaypointPosition();
>>}
>>
>>class AirspaceGraphConcept PropertyGraphConcept<class Graph, class WaypointConcept, class vertex_index_t>;
>>typedef Vertex* GraphPathType; ?
>>typedef string FlightIDType; 
>>typedef boost::unordered_map<std::FlightIDType, GraphPathType> FlightIDToPathAssignmentType;
>>//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
>>
>>Code in the .cpp file (which includes the above header file) I am trying to compile:
>>//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
>>#include <boost/lambda/lambda.hpp>
>>#include <iostream>
>>#include <iterator>
>>#include <algorithm>
>>#include <boost/numeric/ublas/io.hpp>
>>#include <boost/numeric/ublas/vector.hpp>
>>#include "airspace-graph-rectilinear-edges.h"
>>
>>int main()
>>{
>>????using namespace boost::numeric::ublas;
>>
>>????vector<double> v(3);
>>????for (unsigned i = 0; i < v.size(); ++ i)
>>??????v (i) = 2.01*double(i);
>>????
>>????std::cout << v << std::endl;
>>}
>>//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

You seem to missing an
  #include <vector>
and vector should be qualified as std::vector<double>.

Also, I'd consider 
  typedef char* string;
to be moderately evil given that there is a type std::string.

HTH,
Philipp Moeller