complex<float>
描述一个对象，该对象存储两个都为 float 类型的有序对象对，该有序对中的第一个对象表示复数的实部，第二个对象表示复数虚部。
语法
template <>
class complex<float> {
public:
constexpr complex(
float _RealVal = 0,
float _ImagVal = 0);
constexpr complex(
const complex<float>& complexNum);
constexpr complex(
const complex<double>& complexNum);
constexpr complex(
const complex<long double>& complexNum);
// rest same as class template complex
};
参数
_RealVal
正在构造的复数实部的 float 类型值。
_ImagVal
正在构造的复数虚部的 float 类型值。
complexNum
类型为 double 或 long double 的复数，其实部和虚部用于初始化正在构造的 float 类型的复数。
返回值
float 类型的复数。
注解
类模板 complex 显式专用化为 float 类型的 complex 类仅与它所定义构造函数中的类模板不同。 从 float 到 double 类型的转换可以是隐式的，但从 float 到 long double 的转换（安全性较低）必须是 explicit。 使用 explicit 转换可取消在最初使用赋值语法进行类型转换。
有关 complex 类模板的详细信息，请参阅 complex 类。 有关 complex 类模板的成员列表，请参阅。
示例
// complex_comp_flt.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 <float> c1 ( 4.0 , 5.0 );
cout << "Specifying initial real & imaginary parts,\n"
<< " as type float gives c1 = " << c1 << endl;
// The second constructor initializes values of the real &
// imaginary parts using those of complex number of type double
complex <double> c2double ( 1.0 , 3.0 );
complex <float> c2float ( c2double );
cout << "Implicit conversion from type double to type float,"
<< endl << "gives c2float = " << c2float << 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 ( 3.0 , 4.0 );
complex <float> c3float ( c3longdouble );
cout << "Explicit conversion from type long double to type float,"
<< endl << "gives c3float = " << c3float << endl;
// The modulus and argument of a complex number can be recovered
double absc3 = abs ( c3float);
double argc3 = arg ( c3float);
cout << "The modulus of c3 is recovered from c3 using: abs ( c3 ) = "
<< absc3 << endl;
cout << "Argument of c3 is recovered from c3 using:"
<< endl << "arg ( c3 ) = "
<< argc3 << " radians, which is " << argc3 * 180 / pi
<< " degrees." << endl;
}
/* Output:
Specifying initial real & imaginary parts,
as type float gives c1 = (4,5)
Implicit conversion from type double to type float,
gives c2float = (1,3)
Explicit conversion from type long double to type float,
gives c3float = (3,4)
The modulus of c3 is recovered from c3 using: abs ( c3 ) = 5
Argument of c3 is recovered from c3 using:
arg ( c3 ) = 0.927295 radians, which is 53.1301 degrees.
*/
要求
标头：<complex>
命名空间： std