std::complex<T>::real

 

C++

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Numerics library

Common mathematical functions
Mathematical special functions (C++17)
Mathematical constants (C++20)
Basic linear algebra algorithms (C++26)
Floating-point environment (C++11)
Complex numbers
Numeric array (valarray)
Pseudo-random number generation
Factor operations
gcd (C++17)	lcm (C++17)
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midpoint (C++20)	lerp (C++20)
Saturation arithmetic
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)
Bit operations
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)

 

primary template std::complex<T>
	(1)
T real() const;			(until C++14)
constexpr T real() const;			(since C++14)
		(2)
void real( T value );				(until C++20)
constexpr void real( T value );				(since C++20)
specialization std::complex<float>
			(1)
float real() const;					(until C++11)
constexpr float real() const;					(since C++11)
				(2)
void real( float value );						(until C++20)
constexpr void real( float value );						(since C++20)
specialization std::complex<double>
					(1)
double real() const;							(until C++11)
constexpr double real() const;							(since C++11)
						(2)
void real( double value );								(until C++20)
constexpr void real( double value );								(since C++20)
specialization std::complex<long double>
							(1)
long double real() const;									(until C++11)
constexpr long double real() const;									(since C++11)
								(2)
void real( long double value );										(until C++20)
constexpr void real( long double value );										(since C++20)

Accesses the real part of the complex number.

1) Returns the real part.

2) Sets the real part to value.

Parameters

value

-

the value to set the real part to

Return value

1) The real part of *this.

2) (none)

Notes

In C++11, overload (1) in std::complex specializations used to be specified without const qualifier. However, in C++11, a constexpr specifier used in a non-static member function implies const, and thus the behavior is as if const is specified.

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 387	C++98	the real part could not be set directly	can be set directly via a new real overload

See also

real	returns the real part (function template)
imag	accesses the imaginary part of the complex number (public member function)