[RESOLVED] Declara object type based on run time template parameter
Hello to all expert C++ programmer,
Code:
template <typename T, class edgeType = edge>
class graph
{
public:
/*
shared_ptr's template parameter is object
and not pointer to object
*/
typedef boost::shared_ptr<vertex<T> >
vertexPtr;
private:
std::vector<vertexPtr> allVertex;
I want that when different type of edgeType is supplied, then i want instantiated different type of vertexPtr.
I have two type of edgeType, one is edge(undirected) and arcs(Directed).
Whenever user supplied, graph<int, arcs> DAG;, then in the
Code:
typedef boost::shared_ptr<arcs> arcsPtr;
typedef boost::shared_ptr<vertex<T, arcsPtr> > vertexPtr;
should have arcsPtr.
Then, if user graph<int> supplied this, then default vertexPtr should be used.
I hope this make sense to you all.
Traits or CRTP or any design patterns is greatly appreciated by me.
The purpose of this question is to declare a graph class template that works with directed and undirected class based on template parameter.
graph<int> grp -- Undirected;
graph(int, arcs> -- directed;
Thanks for your help.
Re: Declara object type based on run time template parameter
Code:
typedef boost::shared_ptr<edgeType> edgeTypePtr;
typedef boost::shared_ptr<vertex<T, edgeTypePtr> > vertexPtr;
I think that's what you want.
gg
Re: Declara object type based on run time template parameter
Let me rephrase the question.
Code:
If i supplied graph<int>, then in graph
typedef boost::shared_ptr<vertex<T> > vertexPtr;
std::vector<vertexPtr> allVertex;(Undirected graph)
else
graph<int, arcs>
then i need
typedef boost::shared_ptr<vertex<T, arcs> > arcsVertexPtr;
std::vector<arcsVertexPtr> allVertex;(directed graph)
I hope this make more sense.
Thanks.
Re: Declara object type based on run time template parameter
Ah. Then you can use a traits-type template with specialization to "choose" the appropriate type:
Code:
template <typename T, typename edgeType>
struct edgeTypeTraits; // no impl. - just for specialization
template <typename T>
struct edgeTypeTraits<T, edge> // specialized for edge
{
typedef boost::shared_ptr<vertex<T> > vertexPtr_t;
typedef std::vector<vertexPtr_t> allVertex_t;
};//edgeTypeTraits<T, edge>
template <typename T>
struct edgeTypeTraits<T, arcs> // specialized for arcs
{
typedef boost::shared_ptr<vertex<T, arcs> > vertexPtr_t;
typedef std::vector<vertexPtr_t> allVertex_t;
};//edgeTypeTraits<T, edge>
template <typename T, typename edgeType = edge>
struct graph
{
typedef typename edgeTypeTraits<T, edgeType>::vertexPtr_t vertexPtr_t;
typedef typename edgeTypeTraits<T, edgeType>::allVertex_t allVertex_t;
vertexPtr_t m_vp;
allVertex_t m_av;
};//graph
gg
Re: Declara object type based on run time template parameter
I have did what you show but but this doesn't clear it the problem due to numerous compilation problem.
My code:
Code:
#ifndef EDGETYPETRAITS_H
#define EDGETYPETRAITS_H
#include <boost/shared_ptr.hpp>
#include "Arcs.h"
#include "Edge.h"
template <typename T, typename link = edgePtr>
class vertex;
// Base class no definition
template <typename T, typename edgeType>
class edgeTypeTrais;
// Partial Specialization
template <typename T>
class edgeTypeTrais<T, edge>
{
public:
typedef boost::shared_ptr<vertex<int> > vertexPtr;
typedef std::vector<vertexPtr> allVertexVector;
};
// Partial Specialization
template <typename T>
class edgeTypeTraits<T, arcs> ---> [bold]Error[/bold]
{
public:
typedef boost::shared_ptr<vertex<int, arcs> > vertexPtr;
typedef std::vector<vertexPtr> allVertexVector;
};
#endif
The error appear at second edgeTypeTraits class.
If i uncomment the second edgeTypeTraits class,
error appear at here
Code:
typedef typename edgeTypeTraits<T, edgeType::allVertexVector allVertexVector;
allVertexVector allVertex;
Quote:
error C2143: syntax error : missing ';' before '<'
error C2059: syntax error : '<'
error C2143: syntax error : missing ';' before '{'
error C2447: '{' : missing function header (old-style formal list?)
error C2977: 'edgeTypeTraits' : too many template arguments
error C2039: 'vertexPtr' : is not a member of 'edgeTypeTraits'
error C2146: syntax error : missing ';' before identifier 'vertexPtr'
error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
error C2868: 'graph<T,edgeType>::vertexPtr' : illegal syntax for using-declaration; expected qualified-name
warning C4346: 'edgeType::allVertexVector' : dependent name is not a type
error C2146: syntax error : missing ',' before identifier 'allVertexVector'
error C2065: 'allVertexVector' : undeclared identifier
error C2143: syntax error : missing '>' before ';'
error C2208: 'edgeTypeTraits' : no members defined using this type
error C2146: syntax error : missing ';' before identifier 'allVertex'
Error 16 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int d:\c++\data structure\graph\graph\graph.h 31
error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
error C2977: 'edgeTypeTraits' : too many template arguments
Error 19 error C2955: 'edgeTypeTraits' : use of class template requires template argument list
error C2027: use of undefined type 'edgeTypeTraits'
error C2146: syntax error : missing ';' before identifier 'vertexPtr'
error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
error C2602: 'graph<T>::vertexPtr' is not a member of a base class of 'graph<T>'
error C2868: 'graph<T>::vertexPtr' : illegal syntax for using-declaration; expected qualified-name d:\c++\data structure\graph\graph\graph.h 26
error C2039: 'allVertexVector' : is not a member of 'edge'
Error 26 error C2146: syntax error : missing ',' before identifier 'allVertexVector' d:\c++\data structure\graph\graph\graph.h 30
error C2143: syntax error : missing '>' before ';'
error C2208: 'edgeTypeTraits' : no members defined using this type0
error C2146: syntax error : missing ';' before identifier 'allVertex' d:\c++\data structure\graph\graph\graph.h 31
Error 30 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
MS VS 2005
My complete code:
Code:
#ifndef ARCS_H
#define ARCS_H
#include <string>
#include <boost/shared_ptr.hpp>
class arcs
{
private:
int weightage;
std::string toVertex;
public:
arcs();
~arcs();
};
#endif
#include <algorithm>
#include <string>
#include "Arcs.h"
// =============================================
arcs::arcs() : weightage(int (0)), toVertex(std::string(""))
{
}
// =============================================
arcs::~arcs()
{
}
#ifndef EDGE_H
#define EDGE_H
#include <string>
/* arcs is directed edge
edge is undirected edge
*/
class edge
{
private:
// Path's cost
int weightage;
std::string firstVertexID;
std::string secondVertexID;
/* An edge in an undirected graph
is a set of two vertices
An edge is placed twice, once for A->B
B->A
*/
public:
edge();
edge(int);
edge(const edge&);
edge& operator=(const edge&);
void setWeightage(int);
int getWeightage();
void setFirstVertexID(const std::string&);
void setSecondVertexID(const std::string&);
std::string getFirstVertexID();
std::string getSecondVertexID();
~edge();
};
#endif
#include <algorithm>
#include <string>
#include "Edge.h"
// =============================================
edge::edge() : weightage(0),
firstVertexID(std::string("")),
secondVertexID(std::string(""))
{
}
// =============================================
edge::edge(int myWeightage)
: weightage(myWeightage),
firstVertexID(std::string("")),
secondVertexID(std::string(""))
{
}
// =============================================
edge::edge(const edge& that)
: weightage(that.weightage),
firstVertexID(std::string(that.firstVertexID)),
secondVertexID(std::string(that.secondVertexID))
{
}
// =============================================
edge& edge::operator=(const edge& that)
{
if (this != &that)
{
edge tempEdge(that.weightage);
tempEdge.firstVertexID = that.firstVertexID;
tempEdge.secondVertexID = that.secondVertexID;
std::swap(this->weightage,
tempEdge.weightage);
}
return *this;
}
// =============================================
edge::~edge()
{
}
// =============================================
void edge::setWeightage(int userWeightage)
{
weightage = userWeightage;
}
// =============================================
int edge::getWeightage()
{
return this->weightage;
}
// =============================================
void edge::setFirstVertexID(const std::string& userVertexID)
{
firstVertexID = userVertexID;
}
// =============================================
void edge::setSecondVertexID(const std::string& userVertexID)
{
secondVertexID = userVertexID;
}
// =============================================
std::string edge::getFirstVertexID()
{
return firstVertexID;
}
// =============================================
std::string edge::getSecondVertexID()
{
return secondVertexID;
}
// =============================================
#ifndef VERTEX_H
#define VERTEX_H
#include <vector>
#include <string>
#include <boost/shared_ptr.hpp>
#include "Edge.h"
typedef boost::shared_ptr<edge> edgePtr;
template <typename T, typename link = edgePtr>
class vertex
{
public:
typedef boost::shared_ptr<vertex<T> > vertexPtr;
private:
// Number of edge incident from this vertex
int degree;
// Distance from this vertex to another vertex
int fromDistance;
// Vertex name
std::string vertexID;
// Vertex information
T element;
/*
This used to represent/store all edges
incident(attach/link) from/to this vertex
*/
std::vector<link> incidentEdge;
std::vector<vertexPtr> incidentVertex;
public:
vertex();
vertex(const T& );
void decreaseDegree();
void setDegree();
void setDegree(int);
void setFromDistance(int);
void setVertexID(const std::string& );
void setElement(const T&);
void setIncidentEdge(boost::shared_ptr<edge>& );
void setIncidentVertex(boost::shared_ptr<vertex>& );
void deleteEdge(int);
void deleteVertex(int);
int getDegree();
int getFromDistance();
const std::string getVertexID();
const T getElement();
std::vector<link>& getIncidentEdge();
std::vector<typename vertex<T>::vertexPtr>& getIncidentVertex();
~vertex();
};
// =============================================
template <typename T, typename link>
vertex<T, link>::vertex() : degree(0),
fromDistance(0)
vertexID(std::string("")),
element(T()),
incidentEdge(vector<link>()),
incidentVertex(vector<vertexPtr>())
{
}
// =============================================
template <typename T, typename link>
vertex<T, link>::vertex(const T& info) : degree(0),
fromDistance(0), vertexID(std::string()),
element(info),
incidentEdge(vector<link>()),
incidentVertex(vector<vertexPtr>())
{
}
// =============================================
template <typename T, typename link>
vertex<T, link>::~vertex()
{
}
// =============================================
template <typename T, typename link>
void vertex<T, link>::decreaseDegree()
{
--degree;
}
// =============================================
template <typename T, typename link>
void vertex<T, link>::setDegree()
{
++degree;
}
// =============================================
template <typename T, typename link>
void vertex<T, link>::setFromDistance(int userDistance)
{
fromDistance = userDistance;
}
// =============================================
template <typename T, typename link>
void vertex<T, link>::setDegree(int myDegree)
{
degree = myDegree;
}
// =============================================
template <typename T, typename link>
void vertex<T, link>::setVertexID(const std::string& vertexName)
{
vertexID = vertexName;
}
// =============================================
template <typename T, typename link>
void vertex<T, link>::setElement(const T& info)
{
element = info;
}
// =============================================
template <typename T, typename link>
void vertex<T, link>::setIncidentEdge(boost::shared_ptr<edge>& userEdge)
{
incidentEdge.push_back(userEdge);
}
// =============================================
template <typename T, typename link>
void vertex<T, link>::setIncidentVertex(boost::shared_ptr<vertex>& userVertex)
{
incidentVertex.push_back(userVertex);
}
// =============================================
template <typename T, typename link>
void vertex<T, link>::deleteEdge(int position)
{
incidentEdge.erase(incidentEdge.begin() + position);
}
// =============================================
template <typename T, typename link>
void vertex<T, link>::deleteVertex(int position)
{
incidentVertex.erase(incidentVertex.begin() + position);
}
// =============================================
template <typename T, typename link>
int vertex<T, link>::getDegree()
{
return this->degree;
}
// =============================================
template <typename T, typename link>
int vertex<T, link>::getFromDistance()
{
return this->fromDistance;
}
// =============================================
template <typename T, typename link>
const std::string vertex<T, link>::getVertexID()
{
return this->vertexID;
}
// =============================================
template <typename T, typename link>
const T vertex<T, link>::getElement()
{
return this->element;
}
// =============================================
template <typename T, typename link>
std::vector<link>& vertex<T, link>::getIncidentEdge()
{
return this->incidentEdge;
}
// =============================================
template <typename T, typename link>
std::vector<typename vertex<T>::vertexPtr>& vertex<T, link>::getIncidentVertex()
{
return this->incidentVertex;
}
#endif
#ifndef GRAPH_H
#define GRAPH_H
#include <vector>
#include <queue>
#include <limits>
#include "EdgeTypeTraits.h"
// Forward Declaration minimize file dependecies
class edge;
template <typename T, typename link = edgePtr>
class vertex;
template <typename T, class edgeType = edge>
class graph
{
public:
/*
shared_ptr's template parameter is object
and not pointer to object
*/
typedef typename edgeTypeTraits<T, edgeType>::vertexPtr vertexPtr;
private:
typedef typename edgeTypeTraits<T, edgeType::allVertexVector allVertexVector;
allVertexVector allVertex;
};
#endif
Thanks.
Re: Declara object type based on run time template parameter
>> edgeTypeTrais
>> edgeTypeTraits
Spelling
>> typedef typename edgeTypeTraits<T, edgeType::allVertexVector allVertexVector;
Syntax. Missing a '>'
gg
Re: Declara object type based on run time template parameter
