类型萃取实现顺序表
#include <iostream>
#include<string>
using namespace std;
struct TrueType
{
bool get()
{
return true;
}
};
struct FalseType
{
bool get()
{
return false;
}
};
template <typename T>
struct TypeTraits
{
typedef FalseType istPodType;
};
template<>
struct TypeTraits<int>
{
typedef TrueType isPodType;
};
template<typename T>
class Seqlist
{
private:
T *_data;
int _size;
int _capacity;
public:
Seqlist()
:_size(0)
, _capacity(3)
{
_data = new T[_capacity];
}
~Seqlist()
{
if (_data != NULL)
{
delete[]_data;
_data = NULL;
}
}
void CheakCapacity()
{
if (_size == _capacity)
{
if (TypeTraits<T>::isPodType().get())
{
T * tem = new T[_capacity];
memcpy(tem, _data, sizeof(T)*_capacity);
delete[]_data;
_data = tem;
_capacity = 2 * _capacity + 3;
}
else
{
T * tem = new T[_capacity];
int i = 0;
for (i = 0; i < _size; i++)
{
tem[i] = _data[i];
}
delete[]_data;
_data = tem;
_capacity = 2 * _capacity + 3;
}
}
}
void PushBack(const T &d)
{
CheakCapacity();
_data[_size] = d;
_size++;
}
void print()
{
int i = 0;
for (i = 0; i < _size; i++)
cout << _data[i] << " ";
}
};
int main()
{
Seqlist<int> s;
s.PushBack(1);
s.PushBack(2);
s.PushBack(3);
s.PushBack(4);
s.print();
getchar();
return 0;
}
2.类型萃取实现copy函数
#include <iostream>
#include<string>
using namespace std;
struct TrueType
{
bool get()
{
return true;
}
};
struct FalseType
{
bool get()
{
return false;
}
};
template <typename T>
struct TypeTraits
{
typedef FalseType istPodType;
};
template<>
struct TypeTraits<int>
{
typedef TrueType isPodType;
};
template <typename T>
void copy(T *dest, const T *src,int size, TrueType)
{
cout << typeid(T).name() << endl;
memcpy(dest, src, size*sizeof(T));
}
template <typename T>
void copy(T *dest, const T *src, int size, FalseType)
{
cout << typeid(T).name() << endl;
int i = 0;
for (i = 0; i < size; i++)
dest[i] = src[i];
}
int main()
{
int arr1[] = { 1, 2, 3, 4, 5 };
int i = 0;
int arr2[6] = { 0 };
int size1 = sizeof(arr1) / sizeof(arr1[0]);
copy<int>(arr2, arr1,size1, TypeTraits<int>::isPodType());
for (i = 0; i < size1; i++)
cout << arr2[i] << " ";
getchar();
return 0;
}
原文：http://10810512.blog.51cto.com/10800512/1757462