As an exception, a template that is explicitly instantiated for all relevant sets of template arguments, or that is a private implementation detail of a class, is allowed to be defined in the one and members. • It need not have any constructors defined. If a constructor is provided, it must take no arguments and it must be protected. • If it is a subclass, it may only be derived from classes that satisfy defining operators as templates, because they must satisfy this rule for any possible template arguments. If you define an operator, also define any related operators that make sense, and make sure they

definitions should first list arguments without default values, followed by those with default values. In both function definitions and function calls, multiple arguments per line are allowed; line breaks comments should consist of a one-sentence description of the function; a list of the function’s arguments, denoted by Args:, with a description of each (including the data type); and a description of the n != length(y)) { stop("Arguments x and y have different lengths: ", length(x), " and ", length(y), ".") } 6 if (TRUE %in% is.na(x) || TRUE %in% is.na(y)) { stop(" Arguments x and y must not have missing

foo(a, b=0):. If foo is called with only one argument, b is set to 0. If it is called with two arguments, b has the value of the second argument. Pros: Often you have a function that uses lots of default does not support overloaded methods/functions and default arguments are an easy way of “faking” the overloading behavior. Cons: Default arguments are evaluated once at module load time. This may cause problems code, enforce invariants, etc. Cons: Decorators can perform arbitrary operations on a function’s arguments or return values, resulting in surprising implicit behavior. Additionally, dec- 14 orators execute

Critical reading is important for understanding and evaluation  #1 Start open-minded, listen to arguments and trust provided evidence  #2 Don’t accept superficial, contradictory, or unproven claims  #3