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(texinfo)Typed Functions

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Functions in Typed Languages
----------------------------

  The `@deftypefn' command and its variations are for describing
functions in languages in which you must declare types of variables and
functions, such as C and C++.

`@deftypefn CATEGORY DATA-TYPE NAME ARGUMENTS...'
     The `@deftypefn' command is the general definition command for
     functions and similar entities that may take arguments and that are
     typed.  The `@deftypefn' command is written at the beginning of a
     line and is followed on the same line by the category of entity
     being described, the type of the returned value, the name of this
     particular entity, and its arguments, if any.

     For example,

          @deftypefn {Library Function} int foobar
             (int @var{foo}, float @var{bar})
          ...
          @end deftypefn

     (where the text before the "...", shown above as two lines, would
     actually be a single line in a real Texinfo file) produces the
     following in Info:

          -- Library Function: int foobar (int FOO, float BAR)
          ...

     This means that `foobar' is a "library function" that returns an
     `int', and its arguments are FOO (an `int') and BAR (a `float').

     The argument names that you write in `@deftypefn' are not subject
     to an implicit `@var'--since the actual names of the arguments in
     `@deftypefn' are typically scattered among data type names and
     keywords, Texinfo cannot find them without help.  Instead, you
     must write `@var' explicitly around the argument names.  In the
     example above, the argument names are `foo' and `bar'.

     The template for `@deftypefn' is:

          @deftypefn CATEGORY DATA-TYPE NAME ARGUMENTS ...
          BODY-OF-DESCRIPTION
          @end deftypefn

     Note that if the CATEGORY or DATA TYPE is more than one word then
     it must be enclosed in braces to make it a single argument.

     If you are describing a procedure in a language that has packages,
     such as Ada, you might consider using `@deftypefn' in a manner
     somewhat contrary to the convention described in the preceding
     paragraphs.

     For example:

          @deftypefn stacks private push
                  (@var{s}:in out stack;
                  @var{n}:in integer)
          ...
          @end deftypefn

     (The `@deftypefn' arguments are shown split into three lines, but
     would be a single line in a real Texinfo file.)

     In this instance, the procedure is classified as belonging to the
     package `stacks' rather than classified as a `procedure' and its
     data type is described as `private'.  (The name of the procedure
     is `push', and its arguments are S and N.)

     `@deftypefn' creates an entry in the index of functions for NAME.

`@deftypefun DATA-TYPE NAME ARGUMENTS...'
     The `@deftypefun' command is the specialized definition command
     for functions in typed languages.  The command is equivalent to
     `@deftypefn Function ...'.

     Thus,

          @deftypefun int foobar (int @var{foo}, float @var{bar})
          ...
          @end deftypefun

     produces the following in Info:

          -- Function: int foobar (int FOO, float BAR)
          ...

     The template is:

          @deftypefun TYPE NAME ARGUMENTS...
          BODY-OF-DESCRIPTION
          @end deftypefun

     `@deftypefun' creates an entry in the index of functions for NAME.