函数模版定义：

函数模版是通用的函数描述，有时候也被称为参数化类型。

建立模版如下：

template <class Any>

void Swap (Any&a,Any&b){

    Any temp;

    temp = a;

    a=b;

    b =temp;

}

#include <iostream>
template <typename Any>
void Swap(Any& a,Any& b);
struct job
{
	char name[40];
	double salary;
	int floor;
};
template <> void Swap<job>(job& job1,job& job2);
void Show(job &j);
int main()
{
	using namespace std;
	cout.precision(2);
	cout.setf(ios::fixed,ios::floatfield);
	int i= 10, j = 20;
	cout<<"i,j"<<i<<","<<j<<endl;
	cout<<"Using compiler-generated int swapper: "<<endl;
	Swap(i,j);
	cout<<"Now i,j = "<<i<<","<<j<<endl;
	job sue = {"Susan",74000.60,7};
	job sidney = {"Sidney",78060.72,9};
	cout<<"Before job swapping:"<<endl;
	Show(sue);
	Show(sidney);
	Swap(sue,sidney);
	cout<<"After job swapping:"<<endl;
	Show(sue);
	Show(sidney);
	system("pause");
	return 0;
}
template <typename Any>
void Swap(Any& a,Any& b)
{
	Any temp =a;
	a = b;
	b = temp;
}
template<> void Swap<job>(job& job1,job& job2)
{
	double t1;
	int t2;
	t1 = job1.salary;
	job1.salary = job2.salary;
	job2.salary = t1;
	t2 = job1.floor;
	job1.floor = job2.floor;
	job2.floor = t2;
}
void Show(job &j)
{
	using namespace std;
	cout<<j.name<<":$"<<j.salary<<" on floor "<<j.floor<<endl;
}

#include <iostream>
template <class Any>//定义一个模版（用class）
void Swap(Any& a,Any& b);//定义一个模版函数
template <typename Any>//定义一个模版（用typename）
void Swap(Any& a,Any& b,int c);
void show(int a[]);
const int Lim = 8;
int main()
{
	using namespace std;
	int i =0 ,j = 20;
	cout<<"i,j= "<<i<<","<<j<<endl;
	cout<<"using compiler-generated int Swapper"<<endl;
	Swap(i,j);
	cout<<"Now i,j = "<<i<<","<<j<<endl;
	int d1[Lim] = {0,7,0,4,1,7,7,6};
	int d2[Lim] = {0,6,2,0,1,9,6,9};
	cout<<"Original arrays:"<<endl;
	show(d1);
	show(d2);
	system("pause");
	return 0;
}
template <typename Any>
void Swap(Any& a,Any& b)
{
	Any temp;
	temp = a;
	a= b;
	b=temp;
}
template <typename Any>
void Swap(Any& a,Any& b,int c)
{
	for (int i =0 ;i<c;i++)
	{
		Any temp = a[i];
		a[i] = b[i];
		b[i] = temp;
	}
}
void show(int a[])
{
	using namespace std;
	cout<<a[0]<<a[1]<<"/";
	cout<<a[2]<<a[3]<<"/";
	for (int i = 4;i<Lim;i++)
	{
		cout<<a[i];
	}
	cout<<endl;
}

显示具体化

#include <iostream>
template <typename Any>
void Swap(Any& a,Any& b);
struct job
{
	char name[40];
	double salary;
	int floor;
};
template <> void Swap<job>(job& job1,job& job2);//显示具体化声明
void Show(job &j);
int main()
{
	using namespace std;
	cout.precision(2);
	cout.setf(ios::fixed,ios::floatfield);
	int i= 10, j = 20;
	cout<<"i,j"<<i<<","<<j<<endl;
	cout<<"Using compiler-generated int swapper: "<<endl;
	Swap(i,j);
	cout<<"Now i,j = "<<i<<","<<j<<endl;
	job sue = {"Susan",74000.60,7};
	job sidney = {"Sidney",78060.72,9};
	cout<<"Before job swapping:"<<endl;
	Show(sue);
	Show(sidney);
	Swap(sue,sidney);
	cout<<"After job swapping:"<<endl;
	Show(sue);
	Show(sidney);
	system("pause");
	return 0;
}
template <typename Any>
void Swap(Any& a,Any& b)
{
	Any temp =a;
	a = b;
	b = temp;
}
template<> void Swap<job>(job& job1,job& job2)//显示具体化定义（不需要再声明template <typename Any>）
{
	double t1;
	int t2;
	t1 = job1.salary;
	job1.salary = job2.salary;
	job2.salary = t1;
	t2 = job1.floor;
	job1.floor = job2.floor;
	job2.floor = t2;
}
void Show(job &j)
{
	using namespace std;
	cout<<j.name<<":$"<<j.salary<<" on floor "<<j.floor<<endl;
}

显示具体化两种等价声明：

template<>void Swap<int>(int &,int&); ==template<> void Swap(int &,int&);

实例化和具体化

编译器选择使用哪个函数版本

C＋＋ 之函数模版

原文：http://blog.csdn.net/ztk881012/article/details/17650465