修改后的specification模式c++实现，去掉了接口名的I前缀

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//specification.h

#pragma once

template<class T>
class Specification
{
public:
virtual bool IsSatisfiedBy(T candidate) = 0;
virtual Specification<T>* And(Specification<T>* other) = 0;
virtual Specification<T>* Or(Specification<T>* other) = 0;
virtual Specification<T>* Not() = 0;
};

template<class T>
class CompositeSpecification : public Specification<T>
{
public:
virtual bool IsSatisfiedBy(int candidate) = 0;
virtual Specification<T>* And(Specification<T>* other);
virtual Specification<T>* Or(Specification<T>* other);
virtual Specification<T>* Not();
};

template<class T>
class AndSpecification : public CompositeSpecification<T>
{
public:
AndSpecification(Specification<T>* x, Specification<T>* y)
{
  m_one = x;
  m_other = y;
}
virtual bool IsSatisfiedBy(int candidate)
{
  return m_one->IsSatisfiedBy(candidate) && m_other->IsSatisfiedBy(candidate);
}

private:
Specification<T>* m_one;
Specification<T>* m_other;
};

template<class T>
class OrSpecification : public CompositeSpecification<T>
{
public:
OrSpecification(Specification<T>* x, Specification<T>* y)
{
  m_one = x;
  m_other = y;
}
virtual bool IsSatisfiedBy(int candidate)
{
  return m_one->IsSatisfiedBy(candidate) || m_other->IsSatisfiedBy(candidate);
}

private:
Specification<T>* m_one;
Specification<T>* m_other;
};

template<class T>
class NotSpecification : public CompositeSpecification<T>
{
public:
NotSpecification(Specification<T>* x)
{
m_wrapped = x;
}
virtual bool IsSatisfiedBy(int candidate)
{
return !m_wrapped->IsSatisfiedBy(candidate);
}
private:
Specification<T> *m_wrapped;
};

//CompositeSpecification
template<class T>
Specification<T>* CompositeSpecification<T>::And(Specification<T>* other)
{
return new AndSpecification<T>(this, other);
}
template<class T>
Specification<T>* CompositeSpecification<T>::Or(Specification<T>* other)
{
return new OrSpecification<T>(this, other);
}
template<class T>
Specification<T>* CompositeSpecification<T>::Not()
{
return new NotSpecification<T>(this);
}

//test.cpp

#include "specification.h"

#include <vector>
#include <algorithm>
using namespace std;

class OddSpecification : public CompositeSpecification<int>
{
public:
virtual bool IsSatisfiedBy(int candidate)
{
return candidate % 2 != 0;
}
};

class PositiveSpecification : public CompositeSpecification<int>
{
public:
virtual bool IsSatisfiedBy(int candidate)
{
return candidate > 0;
}
};

int main(int argc, char* argv[])
{
vector<int> vint;
for (int i = -5; i < 10; i++)
vint.push_back(i);

Specification<int> *oddSpec = new OddSpecification();
Specification<int> *positiveSpec = new PositiveSpecification();
Specification<int> *oddAndPositiveSpec = oddSpec->And(positiveSpec);

for (vector<int>::iterator it = vint.begin(); it != vint.end(); ++it)
{
  if (oddAndPositiveSpec->IsSatisfiedBy(*it))
   //if (oddSpec->IsSatisfiedBy(*it))
   printf("%d\n", *it);

}

delete oddSpec;
delete positiveSpec;
delete oddAndPositiveSpec;
system("PAUSE");
return 0;
}

//vs2013测试通过

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