Difference between revisions of "cpp/numeric/complex/real2"
From cppreference.com
(Applied P1467R9.) |
(Use letters to mark the additional overloads in order to differentiate them from the real overloads.) |
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| Line 10: | Line 10: | ||
constexpr T real( const std::complex<T>& z ); | constexpr T real( const std::complex<T>& z ); | ||
}} | }} | ||
| − | {{dcl | + | {{dcl h|[[#Notes|Additional overloads]] {{mark since c++11}}}} |
| + | {{dcl header|complex}} | ||
| + | {{dcl rev multi|num=A|dcl1= | ||
float real( float f ); | float real( float f ); | ||
double real( double f ); | double real( double f ); | ||
| Line 22: | Line 24: | ||
constexpr FloatingPoint real( FloatingPoint f ); | constexpr FloatingPoint real( FloatingPoint f ); | ||
}} | }} | ||
| − | {{dcl rev multi|num= | + | {{dcl rev multi|num=B|dcl1= |
template< class Integer > | template< class Integer > | ||
double real( Integer i ); | double real( Integer i ); | ||
| Line 34: | Line 36: | ||
{{rrev|since=c++11| | {{rrev|since=c++11| | ||
| − | @ | + | @A,B@ Additional overloads are provided for all integer and floating-point types, which are treated as complex numbers with zero imaginary part. |
}} | }} | ||
| Line 46: | Line 48: | ||
===Return value=== | ===Return value=== | ||
@1@ The real part of {{c|z}}. | @1@ The real part of {{c|z}}. | ||
| − | @ | + | @A@ {{c|f}}. |
| − | @ | + | @B@ {{c|static_cast<double>(i)}}. |
===Notes=== | ===Notes=== | ||
Latest revision as of 17:41, 12 March 2023
| Defined in header <complex>
|
||
| (1) | ||
template< class T > T real( const std::complex<T>& z ); |
(until C++14) | |
| template< class T > constexpr T real( const std::complex<T>& z ); |
(since C++14) | |
| Additional overloads (since C++11) |
||
| Defined in header <complex>
|
||
| (A) | ||
float real( float f ); double real( double f ); |
(until C++14) | |
| constexpr float real( float f ); constexpr double real( double f ); |
(since C++14) (until C++23) |
|
| template< class FloatingPoint > constexpr FloatingPoint real( FloatingPoint f ); |
(since C++23) | |
| (B) | ||
template< class Integer > double real( Integer i ); |
(until C++14) | |
| template< class Integer > constexpr double real( Integer i ); |
(since C++14) | |
1) Returns the real part of the complex number z, i.e. z.real().
|
A,B) Additional overloads are provided for all integer and floating-point types, which are treated as complex numbers with zero imaginary part.
|
(since C++11) |
Contents |
[edit] Parameters
| z | - | complex value |
| f | - | floating-point value |
| i | - | integer value |
[edit] Return value
1) The real part of z.
A) f.
B) static_cast<double>(i).
[edit] Notes
The additional overloads are not required to be provided exactly as (A,B). They only need to be sufficient to ensure that for their argument num:
- If num has a standard(until C++23) floating-point type
T, then std::real(num) has the same effect as std::real(std::complex<T>(num)). - Otherwise, if num has an integer type, then std::real(num) has the same effect as std::real(std::complex<double>(num)).
[edit] See also
| accesses the real part of the complex number (public member function) | |
| returns the imaginary part (function template) | |
| C documentation for creal
| |
