std::valarray::cshift(3)

💅 std::valarray::cshift(3) — C++ Standard Libary 💅

🌸 NAME 🌸

• std::valarray::cshift — std::valarray::cshift (yes bestie, that's literally the name line, and we're keeping it exactly like that) 💖

✨ Synopsis ✨

Okay so the signature is literally this, no cap:

valarray<T> cshift( int count ) const;

Returns a new valarray of the same size with elements whose positions are shifted circularly by count elements.

A non-negative value of count shifts the elements circularly left count places, and a negative value of count shifts the elements circularly right -count places. Slay. 🌀

🎀 Parameters 🎀

• count — number of positions to shift the elements by.

💖 Return value 💖

The resulting valarray with circularly shifted elements. Periodt. ✨

🧠 Notes 🧠

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.

🧚 Example 🧚

// Run this code

#include <iostream>
#include <valarray>

int main()
{
    std::valarray<int> v{1, 2, 3, 4, 5, 6, 7, 8};

    for (auto const& val : v)
        std::cout << val << ' ';
    std::cout << '\n';

    std::valarray<int> v2 = v.cshift(2);

    for (auto const& val : v2)
        std::cout << val << ' ';
    std::cout << '\n';
}

🖥️ Output 🖥️

1 2 3 4 5 6 7 8
3 4 5 6 7 8 1 2

💀 Defect reports 💀

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

• DR: LWG 618; Applied to: C++98
  • Behavior as published: the expression of the shifted elements contains zero-division if size() is 0
  • Correct behavior: describes the new positions without using expressions

👀 See also 👀

• shift — zero-filling shift the elements of the valarray (public member function).

🙈 Hidden category 🙈

• Pages with unreviewed LWG DR marker

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🫶 Sign-off time, bestie: this page comes from http://cppreference.com, dated 2024.06.10, and the footer name is std::valarray::cshift(3). Bye! 💖✨