std::asin,s...f,std::asinl(3)

💖 std::asin, std::asinf, std::asinl 💖

okay so this is the C++ Standard Libary page (their spelling, not mine 💅) for std::asin, std::asinf, and std::asinl — also known as std::asin,s...f,std::asinl(3) up in the header. we're doing inverse trig, bestie, and it's lowkey iconic.

🌸 NAME 🌸

std::asin, std::asinf, std::asinl — literally the name is just them again. that's it. no extra lore. periodt.

✨ Synopsis ✨

Defined in header <cmath> — here's the whole overload situation, and yes she has range:

Defined in header <cmath>
float       asin ( float num );

double      asin ( double num );                            (until C++23)

long double asin ( long double num );
/* floating-point-type */                                   (since C++23)
            asin ( /* floating-point-type */ num );
(constexpr since C++26)
float       asinf( float num );                     (1) (2) (since C++11)
(constexpr since C++26)
long double asinl( long double num );                   (3) (since C++11)
(constexpr since C++26)
Additional overloads (since C++11)
Defined in header <cmath>
template< class Integer >                               (A)
(constexpr since C++26)
double      asin ( Integer num );

• 1-3) Computes the principal value of the arc sine of num.
• The library provides overloads of std::asin for all cv-unqualified floating-point types as the type of the parameter. (since C++23)
• A) Additional overloads are provided for all integer types, which are treated as double. (since C++11)

🎀 Parameters 🎀

• num — a floating-point or integer value. simple, effective, iconic.

🦋 Return value 🦋

If no errors occur, the arc sine of num (arcsin(num)) in the range [-π/2, +π/2], is returned. slay.

If a domain error occurs, an implementation-defined value is returned (NaN where supported).

If a range error occurs due to underflow, the correct result (after rounding) is returned.

🌈 Error handling 🌈

Errors are reported as specified in math_errhandling.

Domain error occurs if num is outside the range [-1.0, 1.0].

If the implementation supports IEEE floating-point arithmetic (IEC 60559):

• If the argument is ±0, it is returned unmodified.
• If |num| > 1, a domain error occurs and NaN is returned.
• if the argument is NaN, NaN is returned.

👑 Notes 👑

The additional overloads are not required to be provided exactly as (A). They only need to be sufficient to ensure that for their argument num of integer type, std::asin(num) has the same effect as std::asin(static_cast<double>(num)).

💅 Example 💅

// Run this code

#include <cerrno>
#include <cfenv>
#include <cmath>
#include <cstring>
#include <iostream>

// #pragma STDC FENV_ACCESS ON

int main()
{
    std::cout << "asin(1.0) = " << asin(1) << '\n'
              << "2*asin(1.0) = " << 2 * asin(1) << '\n'
              << "asin(-0.5) = " << asin(-0.5) << '\n'
              << "6*asin(-0.5) =" << 6 * asin(-0.5) << '\n';

    // special values
    std::cout << "asin(0.0) = " << asin(0) << " asin(-0.0)=" << asin(-0.0) << '\n';

    // error handling
    errno = 0;
    std::feclearexcept(FE_ALL_EXCEPT);

    std::cout << "asin(1.1) = " << asin(1.1) << '\n';

    if (errno == EDOM)
        std::cout << "    errno == EDOM: " << std::strerror(errno) << '\n';
    if (std::fetestexcept(FE_INVALID))
        std::cout << "    FE_INVALID raised" << '\n';
}

🍓 Possible output: 🍓

asin(1.0) = 1.5708
2*asin(1.0) = 3.14159
asin(-0.5) = -0.523599
6*asin(-0.5) = -3.14159
asin(0.0) = 0 asin(-0.0)=-0
asin(1.1) = nan
    errno == EDOM: Numerical argument out of domain
    FE_INVALID raised

🧚 See also 🧚

• acos, acosf, acosl — computes arc cosine (\({\small\arccos{x}}\)arccos(x)) (function) (C++11) (C++11)
• atan, atanf, atanl — computes arc tangent (\({\small\arctan{x}}\)arctan(x)) (function) (C++11) (C++11)
• atan2, atan2f, atan2l — arc tangent, using signs to determine quadrants (function) (C++11) (C++11)
• sin, sinf, sinl — computes sine (\({\small\sin{x}}\)sin(x)) (function) (C++11) (C++11)
• asin(std::complex) — computes arc sine of a complex number (\({\small\arcsin{z}}\)arcsin(z)) (C++11) (function template)
• asin(std::valarray) — applies the function std::asin to each element of valarray (function template)
• C documentation for asin

source/version + date + page: http://cppreference.com · 2024.06.10 · std::asin,s...f,std::asinl(3) 💖 periodt.