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

 

C++

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Numerics library

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gcd (C++17)	lcm (C++17)
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add_sat (C++26) sub_sat (C++26) saturate_cast (C++26)	mul_sat (C++26) div_sat (C++26)
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iota (C++11) ranges::iota (C++23) accumulate inner_product adjacent_difference partial_sum	reduce (C++17) transform_reduce (C++17) inclusive_scan (C++17) exclusive_scan (C++17) transform_inclusive_scan (C++17) transform_exclusive_scan (C++17)
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has_single_bit (C++20)     bit_cast (C++20) bit_ceil (C++20) bit_floor (C++20) bit_width (C++20) rotl (C++20) rotr (C++20)	popcount (C++20) countl_zero (C++20) countl_one (C++20) countr_zero (C++20) countr_one (C++20) byteswap (C++23) endian (C++20)

 

std::complex

Member functions
complex::complex complex::operator= complex::real complex::imag	complex::operator+=complex::operator-=complex::operator*=complex::operator/=
Non-member functions
operator+operator- operator+operator-operator*operator/ operator==operator!= (until C++20)   operator<<operator>> get(std::complex) (C++26)	real imag abs arg norm conj proj (C++11) polar operator""ioperator""ifoperator""il (C++14)(C++14)(C++14)
Exponential functions
log   log10   exp
Power functions
pow   sqrt
Trigonometric functions
sin   cos tan asin (C++11) acos (C++11) atan (C++11)
Hyperbolic functions
sinh   cosh tanh asinh (C++11) acosh (C++11) atanh (C++11)
Helper types
tuple_size<std::complex> (C++26)
tuple_element<std::complex> (C++26)

 

Defined in header <complex>
constexpr complex<long double> operator""il(long double arg); constexpr complex<long double> operator""il(unsigned long long arg);	(1)	(since C++14)
constexpr complex<double> operator""i(long double arg); constexpr complex<double> operator""i(unsigned long long arg);	(2)	(since C++14)
constexpr complex<float> operator""if(long double arg); constexpr complex<float> operator""if(unsigned long long arg);	(3)	(since C++14)

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

1) forms a literal std::complex<double> with the real part zero and imaginary part arg

2) forms a literal std::complex<float> with the real part zero and imaginary part arg

3) forms a literal std::complex<long double> with the real part zero and imaginary part arg

Parameters

arg

-

the value of the imaginary number

Return value

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

Possible implementation

constexpr std::complex<double> operator""i(unsigned long long d); { return std::complex<double>{0.0, static_cast<double>(d)}. } constexpr std::complex<long double> operator""i(double d); { return std::complex<double>{0.0, d}. }

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 using namespace std::literals and using namespace std::literals::complex_literals.

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

Run this code

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

Output:

abs(1,1) = 1.41421

See also

(constructor)	constructs a complex number (public member function)
C documentation for I