cpp/numeric/special functions/assoc laguerre

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

Return value
If no errors occur, value of the associated Laguerre polynomial of, that is , is returned (where is the unassociated Laguerre polynomial, ).

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 or  is greater or equal to 128, the behavior is implementation-defined