std::abs(std::valarray)(3)

🎀 NAME 🎀

std::abs(std::valarray) - std::abs(std::valarray) — yes, that's literally the whole NAME line, iconic 💅. This is the std::abs(std::valarray) page from the C++ Standard Libary (manual name up top, spelling and all 🫶).

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✨ Synopsis ✨

Defined in header <valarray>
template< class T >
valarray<T> abs( const valarray<T>& va );

Computes absolute value of each element in the value array. 🧮✨

🫶 Parameters 🫶

• va — value array to apply the operation to.

💖 Return value 💖

Value array containing absolute values of the values in va. 🌟

🧠 Notes 🧠

Unqualified function (abs) is used to perform the computation. If such function is not available, std::abs is used due to argument-dependent lookup. 👀

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.

🛠️ Possible implementation 🛠️

template<class T>
valarray<T> abs(const valarray<T>& va)
{
    valarray<T> other = va;
    for (T& i : other)
        i = abs(i);

    return other; // proxy object may be returned
}

🍓 Example 🍓

// Run this code

#include <iostream>
#include <valarray>

int main()
{
    std::valarray<int> v{1, -2, 3, -4, 5, -6, 7, -8};
    std::valarray<int> v2 = std::abs(v);
    for (auto n : v2)
        std::cout << n << ' ';
    std::cout << '\n';
}

🎬 Output: 🎬

1 2 3 4 5 6 7 8

👀 See also 👀

• abs(int)
• labs, llabs — computes absolute value of an integral value (\(\small{|x|}\)|x|) — (function) — (C++11)
• abs(float)
• fabs, fabsf, fabsl — absolute value of a floating point value (\(\small{|x|}\)|x|) — (function) — (C++11) — (C++11)
• abs(std::complex) — returns the magnitude of a complex number — (function template)

🙈 Hidden category: 🙈

• Pages with unreviewed LWG DR marker

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Okay that's the whole vibe, bestie 💅✨ — footer energy: source http://cppreference.com, version/date 2024.06.10, page std::abs(std::valarray)(3) 🫶🎀