C++ valarray Library - Function swap

---

---

Description

It exchanges the contents of *this and x.

Declaration

Following is the declaration for std::valarray::swap function.

 template <class T> void swap (valarray<T>& x, valarray<T>& y) noexcept; 

C++11

 template <class T> void swap (valarray<T>& x, valarray<T>& y) noexcept; 

Parameters

x,y − These are the another valarray objects of the same type.

Return Value

none

Exceptions

Basic guarantee − if any operation performed on the elements throws an exception.

Data races

All elements effectively copied are accessed.

Example

In below example explains about std::valarray::swap function.

 #include <iostream> #include <valarray> int main () { std::valarray<int> foo {0,10,20,30}; std::valarray<int> bar {100,200,300}; foo.swap(bar); std::cout << "foo contains:"; for (auto& x: foo) std::cout << ' ' << x; std::cout << '\n'; std::cout << "bar contains:"; for (auto& x: bar) std::cout << ' ' << x; std::cout << '\n'; return 0; } 

Let us compile and run the above program, this will produce the following result −

 foo contains: 100 200 300 bar contains: 0 10 20 30