std::sin(std::valarray)(3)

💖 std::sin(std::valarray)(3) 💖

okay bestie, welcome to the std::sin(std::valarray)(3) page from the C++ Standard Libary manual — yes, Libary is literally how the manual name is spelled, no cap 😭. This one is all about the valarray glow-up for sine, and it's lowkey iconic.

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🌸 NAME 🌸

std::sin(std::valarray) - std::sin(std::valarray)

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✨ Synopsis ✨

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

For each element in va, this computes the sine of the value of the element. cute, efficient, on theme 💅

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🎀 Parameters 🎀

• va — the value array to apply the operation to, bestie. that's the whole assignment.

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💖 Return value 💖

You get back a value array containing the sine of the values in va. slay.

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🦋 Notes 🦋

okay so here's the lore:

• Unqualified function (sin) is used to perform the computation. If such function is not available, std::sin 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.

this is giving "implementation may be fancy, but the interface keeps the same energy" ✨

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👑 Possible implementation 👑

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

    return other; // proxy object may be returned
}

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🔥 Example 🔥

// Run this code

#include <cmath>
#include <iostream>
#include <numbers>
#include <valarray>

int main()
{
    std::valarray<double> v1 = {0, 0.25, 0.5, 0.75, 1};
    std::valarray<double> v2 = std::sin(v1 * std::numbers::pi);

    for (double n : v2)
        std::cout << std::fixed << n << ' ';
    std::cout << '\n';
}

🌟 Output: 🌟

0.000000 0.707107 1.000000 0.707107 0.000000

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🌈 See also 🌈

• cos(std::valarray) — applies the function std::cos to each element of valarray (function template)
• tan(std::valarray) — applies the function std::tan to each element of valarray (function template)
• asin(std::valarray) — applies the function std::asin to each element of valarray (function template)
• sin, sinf, sinl — this cluster is a little chaotic in the original: sinf is described as "computes sine ((\({\small\sin{x}}\)sin(x)))", sinl is marked (function), and there are two separate (C++11) markers chilling in there. iykyk 🫶
• sin(std::complex) — computes sine of a complex number ((\({\small\sin{z}}\)sin(z))) (function template)

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💀 Hidden category: 💀

• Pages with unreviewed LWG DR marker

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okay bye bestie — this page comes from http://cppreference.com, version/date 2024.06.10, and it's literally std::sin(std::valarray)(3). mwah 💋✨