[gnuastro-devel] [bug #48609] Modifier 'const' should be used for function arguments and results where appropriate

[Vladimir Markelov]

URL:
  <http://savannah.gnu.org/bugs/?48609>

                 Summary: Modifier 'const' should be used for function
arguments and results where appropriate
                 Project: GNU Astronomy Utilities
            Submitted by: vvm
            Submitted on: Sat 23 Jul 2016 06:56:52 PM PDT
                Category: All Gnuastro
                Severity: 3 - Normal
              Item Group: Source code
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any

    _______________________________________________________

Details:

A lot of functions takes pointers to data and returns pointers. It would be
good to mark 'const' pointers if a function does not change the data or a
caller should not change the returned data.

Why:

1. It will be a good hint for a user - a person can easily see if a function
changes his/her data or function just reads them

2. A compiler can be a real helper and warn a user if the user tries to change
the data(returned by a function) that should be changed at all

A good example for #2 is function 'hdutypestring'. It returns 'char*' but
really it returns a pointer to read-only data, so a client code will likely to
crash if, e.g, the client code tries to change the returned value in place. A
compiler warns the user in this case about casting a 'const char*' to 'char
*'.




    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?48609>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/