std::literals::complex_literals::operator""i, operator""if, operator""il

Since C++14

Header: <complex>

Forms a std::complex literal representing an imaginary number.

# Declarations

constexpr complex<double> operator""i( long double arg );
constexpr complex<double> operator""i( unsigned long long arg );

(since C++14)

constexpr complex<float> operator""if( long double arg );
constexpr complex<float> operator""if( unsigned long long arg );

(since C++14)

constexpr complex<long double> operator""il( long double arg );
constexpr complex<long double> operator""il( unsigned long long arg );

(since C++14)

# Parameters

# Return value

The std::complex literal with the real part zero and imaginary part arg.

# Notes

These operators are declared in the namespace std::literals::complex_literals, where both literals and complex_literals are inline namespaces. Access to these operators can be gained with either:

Even though if is a keyword in C++, it is a ud-suffix of the literal operator of the form operator ““if and in the literal expressions such as 1if or 1.0if because it is not separated by whitespace and is not a standalone token.

# Example

#include <complex>
#include <iostream>
 
int main()
{
    using namespace std::complex_literals;
 
    std::complex<double> c = 1.0 + 1i;
    std::cout << "abs" << c << " = " << std::abs(c) << '\n';
 
    std::complex<float> z = 3.0f + 4.0if;
    std::cout << "abs" << z << " = " << std::abs(z) << '\n';
}

# See also