cpp/numeric/special functions/cyl bessel i

@1-3@ Computes the of  and. @A@ Additional overloads are provided for all other combinations of arithmetic types.

Return value
If no errors occur, value of the regular modified cylindrical Bessel function of and, that is $I nu(x) = Σ∞ k=0$ (for $x≥0$), is returned.

Error handling
Errors may be reported as specified in math_errhandling.
 * If the argument is NaN, NaN is returned and domain error is not reported.
 * If $nu≥128$, the behavior is implementation-defined.