Free Function Stereotypes

A free function is a function that is not bound to a particular class. Static methods/functions as well as friend functions (C++) are also considered as free functions.

Type	Description
predicate	Returns a bool derived from the parameters
property	Returns a non-bool derived from the parameters
global-command	Changes a global or a static variable, by a write or by a call on the variable other than a query method
command	Changes a parameter that shares its object with the caller, by a write through the parameter or by a call on the parameter other than a query method
factory	Creates an object with new, std::make_unique, or std::make_shared and returns the object
main	A main function, such as main, Main, wmain, WinMain, wWinMain, _tmain, or _tWinMain
literal	Does not read or change parameters, globals, or static variables
wrapper	Does not change a parameter that shares its object with the caller. Has at least one call to methods of other types or to a free function
empty	Has no statements
unclassified	Fits none of the rules

TABLE 1. Taxonomy of Free Function Stereotypes.

Stereocode labels free functions and static methods only with the option -f. A main function and an empty function get no other stereotype, while a function can carry several of the other stereotypes, such as predicate wrapper.

A returned value is derived from the parameters when the function uses a parameter and a return expression returns a parameter or computes a value, such as return a < b; or return found;.

A parameter shares its object with the caller when it is a C++ reference, pointer, or array to an object that is not const, a C# ref or out parameter or a parameter of a non-primitive type, or a Java parameter of a non-primitive type. A variable passed with ref or out, such as data in Read(ref data), counts as written by the call. The query methods and the ignored calls of the method stereotypes hold for free functions as well.