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Difference between revisions of "cpp/numeric/complex/real2"

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< cpp‎ | numeric‎ | complex
(Typo)
(Use letters to mark the additional overloads in order to differentiate them from the real overloads.)
 
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{{cpp/numeric/complex/navbar}}
 
{{cpp/numeric/complex/navbar}}
 
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{{dcl header | complex}}
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{{dcl rev multi|num=1|dcl1=
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{{dcl | num=1 | until=c++14 | 1=
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template< class T >  
 
template< class T >  
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T real( const complex<T>& z );
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T real( const std::complex<T>& z );
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|since2=c++14|dcl2=
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{{dcl | num=1 | since=c++14 | 1=
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template< class T >  
 
template< class T >  
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constexpr T real( const complex<T>& z );
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constexpr T real( const std::complex<T>& z );
 
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{{dcl h|[[#Notes|Additional overloads]] {{mark since c++11}}}}
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{{dcl header|complex}}
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long double real( long double z );
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float      real( float f );
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double      real( double f );
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long double real( long double f );
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|since2=c++14|dcl2=
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constexpr float      real( float f );
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constexpr double      real( double f );
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constexpr long double real( long double f );
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|since3=c++23|dcl3=
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template< class FloatingPoint >
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constexpr FloatingPoint real( FloatingPoint f );
 
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{{dcl | num=3 | since=c++11 | 1=
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{{dcl rev multi|num=B|dcl1=
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template< class DoubleOrInteger >
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template< class Integer >
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double real( DoubleOrInteger z );
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double real( Integer i );
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}}
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template< class Integer >
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float real( float z );
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constexpr double real( Integer i );
 
}}
 
}}
 
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{{dcl end}}
  
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Returns the real component of the complex number {{tt|z}}, i.e. {{c|z.real()}}.
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@1@ Returns the real part of the complex number {{c|z}}, i.e. {{c|z.real()}}.
  
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{{rev inl|since=c++11|Additional overloads are provided for {{c|float}}, {{c|double}}, {{c|long double}}, and all integer types, which are treated as complex numbers with zero imaginary component.}}
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{{rrev|since=c++11|
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@A,B@ Additional overloads are provided for all integer and floating-point types, which are treated as complex numbers with zero imaginary part.
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}}
  
 
===Parameters===
 
===Parameters===
 
{{par begin}}
 
{{par begin}}
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{{par | z | complex value}}
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{{par|z|complex value}}
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{{par|f|floating-point value}}
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{{par|i|integer value}}
 
{{par end}}
 
{{par end}}
  
 
===Return value===
 
===Return value===
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@1@ The real part of {{c|z}}.
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@A@ {{c|f}}.
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@B@ {{c|static_cast<double>(i)}}.
  
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the real component of {{tt|z}}
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===Notes===
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{{cpp/numeric/complex/additional overload note|real}}
  
 
===See also===
 
===See also===
 
{{dsc begin}}
 
{{dsc begin}}
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{{dsc inc | cpp/numeric/complex/dsc real}}
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{{dsc inc|cpp/numeric/complex/dsc real}}
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{{dsc inc | cpp/numeric/complex/dsc imag2}}
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{{dsc inc|cpp/numeric/complex/dsc imag2}}
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{{dsc see c | c/numeric/complex/creal}}
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{{dsc see c|c/numeric/complex/creal}}
 
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[[de:cpp/numeric/complex/real2]]
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Latest revision as of 17:41, 12 March 2023

 
C++
 
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
(C++17)
(C++17)
Interpolations
(C++20)
(C++20)
Saturation arithmetic
(C++26)
(C++26)
(C++26)
(C++26)
(C++26)

Generic numeric operations
Bit operations
(C++20)    
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++23)
(C++20)
 
std::complex
 
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 );

long double real( long double f );
 (until C++14)
constexpr float       real( float f );

constexpr double      real( double f );

constexpr long double real( long 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) [edit]
returns the imaginary part
(function template) [edit]
C documentation for creal
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