cpp/numeric/special functions/laguerre

@1-3@ Computes the non-associated of the degree  and argument. @A@ Additional overloads are provided for all integer types, which are treated as.

Return value
If no errors occur, value of the nonassociated Laguerre polynomial of, that is $(xn )$, 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 is negative, a domain error may occur
 * If is greater or equal than 128, the behavior is implementation-defined