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operator<<,>>(std::complex)

From cppreference.com
< cpp‎ | numeric‎ | complex
 
 
 
 
Defined in header <complex>
template< class T, class CharT, class Traits >

std::basic_ostream<CharT, Traits>&

    operator<<( std::basic_ostream<CharT, Traits>& os, const std::complex<T>& x );
(1)
template< class T, class CharT, class Traits >

std::basic_istream<CharT, Traits>&

    operator>>( std::basic_istream<CharT, Traits>& is, std::complex<T>& x );
(2)
1) Writes to os the complex number in the form (real, imaginary).
2) Reads a complex number from is. The supported formats are
  • real
  • (real)
  • (real, imaginary)

where the input for real and imaginary must be convertible to T.

If an error occurs calls is.setstate(ios_base::failbit).

Contents

[edit] Exceptions

May throw std::ios_base::failure on stream errors.

[edit] Parameters

os - a character output stream
is - a character input stream
x - the complex number to be inserted or extracted

[edit] Return value

1) os
2) is

[edit] Notes

1) As the comma may be used in the current locale as decimal separator, the output may be ambiguous. This can be solved with std::showpoint which forces the decimal separator to be visible.
2) The input is performed as a series of simple formatted extractions. Whitespace skipping is the same for each of them.

[edit] Possible implementation

template<class T, class CharT, class Traits>
basic_ostream<CharT, Traits>&
    operator<<(basic_ostream<CharT, Traits>& o, const complex<T>& x)
{
    basic_ostringstream<CharT, Traits> s;
    s.flags(o.flags());
    s.imbue(o.getloc());
    s.precision(o.precision());
    s << '(' << x.real() << ',' << x.imag() << ')';
    return o << s.str();
}

[edit] Example

#include <complex>
#include <iostream>
 
int main()
{
    std::cout << std::complex<double> {3.14, 2.71} << '\n';
}

Possible output:

(3.14,2.71)