| Common mathematical functions | |||||||||||||||||||||||||||||||
| Mathematical special functions(C++17) | |||||||||||||||||||||||||||||||
| Mathematical constants(C++20) | |||||||||||||||||||||||||||||||
| Basic linear algebra algorithms(C++26) | |||||||||||||||||||||||||||||||
| Data-parallel types (SIMD)(C++26) | |||||||||||||||||||||||||||||||
| Floating-point environment(C++11) | |||||||||||||||||||||||||||||||
| Complex numbers | |||||||||||||||||||||||||||||||
Numeric array (valarray) | |||||||||||||||||||||||||||||||
| Pseudo-random number generation | |||||||||||||||||||||||||||||||
| Bit manipulation(C++20) | |||||||||||||||||||||||||||||||
| Saturation arithmetic(C++26) | |||||||||||||||||||||||||||||||
| Factor operations | |||||||||||||||||||||||||||||||
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| Interpolations | |||||||||||||||||||||||||||||||
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| Generic numeric operations | |||||||||||||||||||||||||||||||
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| C-style checked integer arithmetic | |||||||||||||||||||||||||||||||
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primary templatestd::complex<T> | ||
| (1) | ||
T real()const; | (until C++14) | |
constexpr T real()const; | (since C++14) | |
| (2) | ||
void real( T value); | (until C++20) | |
constexprvoid real( T value); | (since C++20) | |
specializationstd::complex<float> | ||
| (1) | ||
float real()const; | (until C++11) | |
constexprfloat real()const; | (since C++11) | |
| (2) | ||
void real(float value); | (until C++20) | |
constexprvoid real(float value); | (since C++20) | |
specializationstd::complex<double> | ||
| (1) | ||
double real()const; | (until C++11) | |
constexprdouble real()const; | (since C++11) | |
| (2) | ||
void real(double value); | (until C++20) | |
constexprvoid real(double value); | (since C++20) | |
specializationstd::complex<longdouble> | ||
| (1) | ||
longdouble real()const; | (until C++11) | |
constexprlongdouble real()const; | (since C++11) | |
| (2) | ||
void real(longdouble value); | (until C++20) | |
constexprvoid real(longdouble value); | (since C++20) | |
Accesses the real part of the complex number.
Contents |
| value | - | the value to set the real part to |
In C++11, overload(1) instd::complex specializations used to be specified withoutconst qualifier. However, in C++11, aconstexpr specifier used in a non-static member function impliesconst, and thus the behavior is as ifconst is specified.
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 newreal overload |
| returns the real part (function template)[edit] | |
| accesses the imaginary part of the complex number (public member function)[edit] |
