#include <iostream>

using namespace std;

/**

 * 定义模板函数swapNum

 * 实现功能：交换两个数的位置

 */

template <typename T>

void swap(T &a,T &b)

{

    T temp = a;

    a = b;

    b = temp;

}

int main(void)

{

    int x = 10;

    int y = 20;

    // 调用模板函数

    swap<int>(x,y);

        cout << "x = " << x << endl;

        cout << "y = " << y << endl;

return 0;

}

l报错：/477/9670/FmcL/index.cpp: In function 'int main()':
/477/9670/FmcL/index.cpp:22:18: error: call of overloaded 'swap(int&, int&)' is ambiguous
    swap(x,y);
                 ^
/477/9670/FmcL/index.cpp:22:18: note: candidates are:
/477/9670/FmcL/index.cpp:9:6: note: void swap(T&, T&) [with T = int]
void swap(T &a,T &b)
     ^
In file included from /usr/include/c++/4.8.2/bits/stl_pair.h:59:0,
                from /usr/include/c++/4.8.2/bits/stl_algobase.h:64,
                from /usr/include/c++/4.8.2/bits/char_traits.h:39,
                from /usr/include/c++/4.8.2/ios:40,
                from /usr/include/c++/4.8.2/ostream:38,
                from /usr/include/c++/4.8.2/iostream:39,
                from /477/9670/FmcL/index.cpp:1:
/usr/include/c++/4.8.2/bits/move.h:166:5: note: void std::swap(_Tp&, _Tp&) [with _Tp = int]
    swap(_Tp& __a, _Tp& __b)
    ^