complex<double>

项目
06/09/2015

存储描述了排序的对象对两个 double类型*，*第一表示复数实部和秒表示虚部的对象。

template<>
   class complex<double> {
public:
   complex(
      double _RealVal = 0, 
      double _ImagVal = 0
   );

   complex(
      const complex<double>& _ComplexNum
   );
   explicit complex(
      const complex<long double>& _ComplexNum
   );
   // rest same as template class complex
};

参数

_RealVal
值构造的复数的重载的 double 类型。
_ImagVal
值构造的复数的虚部的 double 类型。
_ComplexNum
浮动类型复数物理和虚部用于初始化类型构造的 double 复数形式的或类型 long double。

返回值

复数 double类型。

备注

模板类的显式专用化复杂到 double 类型复杂的类与它定义的模板仅类不同于构造函数。浮动的 double 允许从转换是隐式的，但是，从 long double 到 double 要求的转换为 explicit。使用分配语法，使用 explicit 排除与类型转换的启动。

有关类模板 complex的更多信息，请参见 complex 类。有关 complex类模板的成员列表，请参见复杂成员。

示例

// complex_comp_dbl.cpp
// compile with: /EHsc
#include <complex>
#include <iostream>

int main( )
{
   using namespace std;
   double pi = 3.14159265359;

   // The first constructor specifies real & imaginary parts
   complex <double> c1 ( 4.0 , 5.0 );
   cout << "Specifying initial real & imaginary parts,\n"
        << " as type double gives c1 = " << c1 << endl;

   // The second constructor initializes values of the real &
   // imaginary parts using those of complex number of type float
   complex <float> c2float ( 4.0 , 5.0 );
   complex <double> c2double ( c2float );
   cout << "Implicit conversion from type float to type double,"
        << "\n gives c2double = " << c2double << endl;

   // The third constructor initializes values of the real &
   // imaginary parts using those of a complex number
   // of type long double
   complex <long double> c3longdouble ( 4.0 , 5.0 );
   complex <double> c3double ( c3longdouble );
   cout << "Explicit conversion from type float to type double,"
        << "\n gives c3longdouble = " << c3longdouble << endl;

   // The modulus and argument of a complex number can be recovered
   double absc3 = abs ( c3longdouble );
   double argc3 = arg ( c3longdouble );
   cout << "The modulus of c3 is recovered from c3 using: abs ( c3 ) = "
        << absc3 << endl;
   cout << "Argument of c3 is recovered from c3 using:\n arg ( c3 ) = "
        << argc3 << " radians, which is " << argc3 * 180 / pi
        << " degrees." << endl;
}