cpp/numeric/math/asinh

@1-3@ Computes the inverse hyperbolic sine of. @A@ Additional overloads are provided for all integer types, which are treated as.

Return value
If no errors occur, the inverse hyperbolic sine of ($sinh-1 (num)$, or $arsinh(num)$), is returned.

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.

If the implementation supports IEEE floating-point arithmetic (IEC 60559),
 * if the argument is ±0 or ±∞, it is returned unmodified
 * if the argument is NaN, NaN is returned