c++ - 重载函数不适用于复杂的

Question

我编写了这个简单的 C++ 代码来交换任意两个变量。它适用于 int 和 double，但不适用于复数，知道为什么吗？

#include <iostream>  
#include <complex>  

using std::cout; 
using std::endl; 
using std::complex; 

template <class T>

inline void swap(T& d, T& s)
{
    T temp = d;
    d = s;
    s = temp;
}


int main()
{
   int m=5, n=10;
   double x=5.3, y=10.6;
   complex<double> r(2.4, 3.5), s(3.4, 6.7);

   cout << "inputs:  " << m << " , " << n << endl;
   swap(m, n);
   cout << "outputs: " << m << " , " << n << endl;

   cout << "double inputs:  " << x << " , " << y << endl;
   swap(x, y);
   cout << "double outputs: " << x << " , " << y << endl;

   cout << "complex inputs:  " << r << " , " << s << endl;
   swap(r, s);
   cout << "complex outputs: " << r << " , " << s << endl;
}

这是错误:

g++ 02.swap.template.cpp -o c.out.02
02.swap.template.cpp: In function ‘int main()’:
02.swap.template.cpp:37:13: error: call of overloaded ‘swap(std::complex<double>&, std::complex<double>&)’ is ambiguous
02.swap.template.cpp:37:13: note: candidates are:
02.swap.template.cpp:13:13: note: void swap(T&, T&) [with T = std::complex<double>]
/usr/include/c++/4.6/bits/move.h:122:5: note: void std::swap(_Tp&, _Tp&) [with _Tp = std::complex<double>]

Answer 1

名称冲突，更改为::swap 解决了问题。