Defined in header <valarray> | ||
---|---|---|
template <class T> std::valarray<T> operator+ (const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator- (const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator* (const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator/ (const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator% (const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator& (const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator| (const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator^ (const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator<<(const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator>>(const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<bool> operator&&(const std::valarray<T>& lhs, const std::valarray<T>& rhs); template <class T> std::valarray<bool> operator||(const std::valarray<T>& lhs, const std::valarray<T>& rhs); | (1) | |
template <class T> std::valarray<T> operator+ (const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator- (const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator* (const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator/ (const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator% (const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator& (const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator| (const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator^ (const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator<<(const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<T> operator>>(const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<bool> operator&&(const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); template <class T> std::valarray<bool> operator||(const typename std::valarray<T>::value_type & val, const std::valarray<T>& rhs); | (2) | |
template <class T> std::valarray<T> operator+ (const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<T> operator- (const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<T> operator* (const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<T> operator/ (const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<T> operator% (const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<T> operator& (const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<T> operator| (const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<T> operator^ (const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<T> operator<<(const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<T> operator>>(const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<bool> operator&&(const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); template <class T> std::valarray<bool> operator||(const std::valarray<T>& lhs, const typename std::valarray<T>::value_type & val); | (3) |
Apply binary operators to each element of two valarrays, or a valarray and a value.
rhs | - | a numeric array |
lhs | - | a numeric array |
val | - | a value of type T |
A valarray with the same size as the parameter.
The behaviour is undefined when the two arguments are valarrays with different sizes.
The function can be implemented with the return type different from std::valarray
. In this case, the replacement type has the following properties:
const
member functions of std::valarray
are provided. std::valarray
, std::slice_array
, std::gslice_array
, std::mask_array
and std::indirect_array
can be constructed from the replacement type. const std::valarray&
except begin()
and end()
(since C++11) should also accept the replacement type. const std::valarray&
should accept every combination of const std::valarray&
and the replacement type. The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR | Applied to | Behavior as published | Correct behavior |
---|---|---|---|
LWG 3074 | C++98 | T is deduced from both the scalar and the valarray for (2-3), disallowing mixed-type calls | only deduce T from the valarray |
Finds real roots of multiple quadratic equations.
#include <valarray> #include <iostream> int main() { std::valarray<double> a(1, 8); std::valarray<double> b{1, 2, 3, 4, 5, 6, 7, 8}; std::valarray<double> c = -b; // literals must also be of type T (double in this case) std::valarray<double> d = std::sqrt((b * b - 4.0 * a * c)); std::valarray<double> x1 = (-b - d) / (2.0 * a); std::valarray<double> x2 = (-b + d) / (2.0 * a); std::cout << "quadratic equation root 1, root 2" << "\n"; for (size_t i = 0; i < a.size(); ++i) { std::cout << a[i] << "x\u00B2 + " << b[i] << "x + " << c[i] << " = 0 "; std::cout << x1[i] << ", " << x2[i] << "\n"; } }
Output:
quadratic equation root 1, root 2 1x² + 1x + -1 = 0 -1.61803, 0.618034 1x² + 2x + -2 = 0 -2.73205, 0.732051 1x² + 3x + -3 = 0 -3.79129, 0.791288 1x² + 4x + -4 = 0 -4.82843, 0.828427 1x² + 5x + -5 = 0 -5.8541, 0.854102 1x² + 6x + -6 = 0 -6.87298, 0.872983 1x² + 7x + -7 = 0 -7.88748, 0.887482 1x² + 8x + -8 = 0 -8.89898, 0.898979
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