前言
正文
C++中模版语法解
1， 模版参数做特殊化设计
#include <iostream>
template<class T, class O>
class ctest_class
{
public:
ctest_class()
{
std::cout << "I, O" << std::endl;
}
// static int m_data;
};
//特殊化处理
template<class T>
class ctest_class<T*, T*>
{
public:
ctest_class()
{
std::cout << "T*, T*" << std::endl;
}
};
//特殊化处理
template<class T>
class ctest_class<const T*, T*>
{
public:
ctest_class()
{
std::cout << "const T* , T*" << std::endl;
}
};
int main(int argc, char *argv[])
{
ctest_class<int, char> obj1; // T, O
ctest_class<int*, int *> obj2; // T*, T*
ctest_class<const int*, int*> obj3;// const T*, T*
system("puase");
return EXIT_SUCCESS;
}
2， 内部没有用到这一常量定义
成员( members)函数使用template
template<class T>
class ccalloc {};
template<class T, class Alloc = ccalloc>
class cvertor
{
public:
typedef T value_type;
typedef value_type* iterator;
template<class I>
void insert(iterator position, I first, I last)
{
std::cout << "insert()" << std::endl;
}
};
int main(int argc, char *argv[])
{
{
int la[5] = { 1, 3, 4,5, 6 };
cvertor<int> x;
cvertor<int>::iterator iter = NULL;
x.insert(iter, la, la + 5);
}
system("puase");
return EXIT_SUCCESS;
}
3， template参数可根据前一个template参数而设定默认值
class ccalloc {};
template<class T, class Alloc = ccalloc, size_t buffsize = 0>
class cdeque
{
public:
cdeque()
{
std::cout << "cdeque" << std::endl;
}
};
template<class T, class csequence = cdeque<T>>
class cstatck
{
public:
cstatck()
{
std::cout << "cstatck " << std::endl;
}
private:
csequence m_data;
};
int main(int argc, char *argv[])
{
{
cstatck<int> x;
}
system("puase");
return EXIT_SUCCESS;
}
4， class template 可否拥有non-type template 参数
class ccalloc {};
inline size_t __deque_buf_size(size_t n, size_t sz)
{
return n != 0 ? n : (sz < 512 ? size_t(512 / sz) : size_t(1));
}
template<class T, class ref, class ptr, size_t bufsize>
struct __deque_iterator
{
typedef __deque_iterator<T, T&, T*, bufsize> iterator;
typedef __deque_iterator<T, const T&, const T*, bufsize> const_iterator;
static size_t buffer_size()
{
return __deque_buf_size(bufsize, sizeof(T));
}
};
template<class T, class Alloc = ccalloc, size_t buffsize = 0>
class ccdeque
{
public:
typedef __deque_iterator<T, T&, T*, buffsize> iterator;
};
int main(int argc, char *argv[])
{
{
std::cout << ccdeque<int>::iterator::buffer_size() << std::endl;
std::cout << ccdeque<int, ccalloc, 64>::iterator::buffer_size() << std::endl;
}
system("puase");
return EXIT_SUCCESS;
}
5， 模版特化
class ccalloc {};
template<class T, class Alloc = ccalloc, size_t buffsize = 0>
class cdeque
{
public:
cdeque()
{
std::cout << "cdeque" << std::endl;
}
};
//
template<class T, class sequence = cdeque<T>>
class statck
{
public:
// friend 有问题？？？？
//friend bool operator<<T>(const statck<T, sequence>&, const statck<T, sequence>&);
////或者
//friend bool operator==<T>(const statck&, const statck&);
//friend bool operator<<T>(const statck&, const statck&);
////或者
//friend bool operator==<>(const statck&, const statck&);
//friend bool operator< <>(const statck&, const statck&);
public:
statck()
{
std::cout << "stack " << std::endl;
}
private:
sequence m_data;
};
//
template<class T, class sequence>
bool operator==(const statck<T, sequence>&x, const statck<T, sequence>&y)
{
std::cout << "operator == " << std::endl;
return true;
}
//template<class _Ty,
// class _Container> inline
// bool operator==(const stack<_Ty, _Container>& _Left,
// const stack<_Ty, _Container>& _Right)
//{ // test for stack equality
// return (_Left._Get_container() == _Right._Get_container());
//}
//template<class T, class sequence>
//bool operator==(const statck<T, sequence>&x, const statck<T, sequence>&y)
//{
// std::cout << "operator ==" << std::endl;
// return true;
//}
////
//template<class T, class sequence>
//bool operator<(const statck<T, sequence>&x, statck<T, sequence>&y)
//{
// std::cout << "operator <" << std::endl;
// return true;
//}
int main(int argc, char *argv[])
{/*
ctest_class<int, char> obj1;
ctest_class<int*, int *> obj2;
ctest_class<const int*, int*> obj3;
{
int la[5] = { 1, 3, 4,5, 6 };
cvertor<int> x;
cvertor<int>::iterator iter = NULL;
x.insert(iter, la, la + 5);
}
{
cstatck<int> x;
}
{
std::cout << ccdeque<int>::iterator::buffer_size() << std::endl;
std::cout << ccdeque<int, ccalloc, 64>::iterator::buffer_size() << std::endl;
}*/
{
/*std::stack < int> x1;
std::stack<int> x2;*/
// x1 == x2;
statck<int> x;
statck<int> y;
x == y;
// //x < y;
// statck<char > y1;
}
system("puase");
return EXIT_SUCCESS;
}
