std::valarray<T>::operator+,-,~,!
From cppreference.com
valarray<T> operator+() const; |
(1) | |
valarray<T> operator-() const; |
(2) | |
valarray<T> operator~() const; |
(3) | |
valarray<bool> operator!() const; |
(4) | |
Applies unary operators to each element in the numeric array.
Contents |
[edit] Parameters
(none)
[edit] Return value
A numeric array containing elements with values obtained by applying corresponding operator to the values in *this.
[edit] Exceptions
May throw implementation-defined exceptions.
[edit] Notes
Each of the operators can only be instantiated if the following requirements are met:
- The indicated operator can be applied to type
T
. - The result value can be unambiguously converted to
T
(1-3) or bool (4).
- The indicated operator can be applied to type
The function can be implemented with the return type different from std::valarray. In this case, the replacement type has the following properties:
- All 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.
- For every function taking a const std::valarray<T>& except begin() and end()(since C++11), identical functions taking the replacement types shall be added;
- For every function taking two const std::valarray<T>& arguments, identical functions taking every combination of const std::valarray<T>& and replacement types shall be added.
- The return type does not add more than two levels of template nesting over the most deeply-nested argument type.
[edit] Example
Run this code
#include <iostream> #include <string_view> #include <valarray> template<typename T> void print(std::string_view const note, std::valarray<T> const vala, // by-value, see Notes above std::string_view const term = "\n") { std::cout << note << std::boolalpha << std::showpos; for (T const element : vala) std::cout << '\t' << element; std::cout << term; } int main() { std::valarray<int> x{1, 2, 3, 4}; print<int>("x: ", x); print<int>("+x: ", +x); print<int>("+ + x: ", + + x); print<int>("-x: ", -x); print<int>("- - x: ", - - x, "\n\n"); std::valarray<short> y{0, 1, -1, 0x7fff}; print<short>("y: ", y); print<short>("~y: ", ~y); print<short>("~~y: ", ~~y, "\n\n"); std::valarray<bool> z{true, false}; print<bool>("z: ", z); print<bool>("!z: ", !z); print<bool>("!!z: ", !!z); }
Possible output:
x: +1 +2 +3 +4 +x: +1 +2 +3 +4 + + x: +1 +2 +3 +4 -x: -1 -2 -3 -4 - - x: +1 +2 +3 +4 y: +0 +1 -1 +32767 ~y: -1 -2 +0 -32768 ~~y: +0 +1 -1 +32767 z: true false !z: false true !!z: true false
[edit] See also
applies compound assignment operator to each element of the valarray (public member function) | |
applies binary operators to each element of two valarrays, or a valarray and a value (function template) |