complex::complex

建構具有指定實數與虛數部分或作為其他一些複數複本的複數。

constexpr complex( 
    const T& RealVal = 0,  
    const T& ImagVal = 0 
); 

constexpr complex( const complex& ); 

template<class Other> 
   constexpr complex( 
      const complex<Other>& ComplexNum 
   );

參數

• RealVal
  用於初始化建構中複數之實數部分的值。

• ImagVal
  用於初始化建構中複數之虛數部分的值。

• ComplexNum
  其實數及虛數用於初始化建構中之複數的複數。

備註

第一個建構函式將儲存的實數部分初始化至 RealVal 並將儲存的虛數部分初始化至 Imagval。 第二個建構函式將儲存的實數部分初始化至 ComplexNum**.real**() 並將儲存的虛數部分初始化至 ComplexNum**.imag**()。

在此實作中，若轉譯器不支援成員樣板函式，此樣板：

template<class Other>
   complex(const complex<Other>& right);

取代為：

complex(const complex& right);

此為複製建構函式。

範例

// complex_complex.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,"
        << "c1 = " << c1 << endl; 

   // The second constructor initializes values of the real &
   // imaginary parts using those of another complex number
   complex <double> c2 ( c1 );
   cout << "Initializing with the real and imaginary parts of c1,"
        << " c2 = " << c2 << endl; 

   // Complex numbers can be initialized in polar form
   // but will be stored in Cartesian form
   complex <double> c3 ( polar ( sqrt( (double)8 ) , pi / 4 ) );
   cout << "c3 = polar ( sqrt ( 8 ) , pi / 4 ) = " << c3 << endl; 

   // The modulus and argument of a complex number can be recovered
   double absc3 = abs ( c3 );
   double argc3 = arg ( c3 );
   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;
}

輸出

Specifying initial real & imaginary parts,c1 = (4,5)
Initializing with the real and imaginary parts of c1, c2 = (4,5)
c3 = polar ( sqrt ( 8 ) , pi / 4 ) = (2,2)
The modulus of c3 is recovered from c3 using: abs ( c3 ) = 2.82843
Argument of c3 is recovered from c3 using:
 arg ( c3 ) = 0.785398 radians, which is 45 degrees.

需求

標頭： <complex>

命名空間: std

請參閱

參考

complex 類別