[clang-tidy] Update documentation of check bugprone-unused-return-value [NFC].

[balazske]

Summary

The list of checked functions was incomplete in the description.

[steakhal]

I checked the list, now it's complete.
Thanks.

[aaron.ballman]

LGTM, thanks!

[Eugene.Zelenko]

clang-tools-extra/docs/clang-tidy/checks/bugprone-unused-return-value.rst

16

I think will be good idea to maintain list style as later entries. Some comments may be added after name.

clang-tools-extra/docs/clang-tidy/checks/bugprone-unused-return-value.rst

 .. title:: clang-tidy - bugprone-unused-return-value
 
 bugprone-unused-return-value
 ============================
 
 Warns on unused function return values. The checked functions can be configured.
 
 Options
 -------
 
 .. option:: CheckedFunctions
 
-   Semicolon-separated list of functions to check. Defaults to
-   ``::std::async;::std::launder;::std::remove;::std::remove_if;::std::unique;::std::unique_ptr::release;::std::basic_string::empty;::std::vector::empty``.
-   This means that the calls to following functions are checked by default:
+   Semicolon-separated list of functions to check. The function is checked if
+   the name and scope matches, with any arguments.
+   By default the following functions are checked:
+   ``std::async, std::launder, std::remove, std::remove_if, std::unique,
+   std::unique_ptr::release, std::basic_string::empty, std::vector::empty,
+   std::back_inserter, std::distance, std::find, std::find_if, std::inserter,
+   std::lower_bound, std::make_pair, std::map::count, std::map::find,
+   std::map::lower_bound, std::multimap::equal_range,
+   std::multimap::upper_bound, std::set::count, std::set::find, std::setfill,
+   std::setprecision, std::setw, std::upper_bound, std::vector::at,
+   bsearch, ferror, feof, isalnum, isalpha, isblank, iscntrl, isdigit, isgraph,
+   islower, isprint, ispunct, isspace, isupper, iswalnum, iswprint, iswspace,
+   isxdigit, memchr, memcmp, strcmp, strcoll, strncmp, strpbrk, strrchr,
+   strspn, strstr, wcscmp, access, bind, connect, difftime, dlsym, fnmatch,
+   getaddrinfo, getopt, htonl, htons, iconv_open, inet_addr, isascii, isatty,
+   mmap, newlocale, openat, pathconf, pthread_equal, pthread_getspecific,
+   pthread_mutex_trylock, readdir, readlink, recvmsg, regexec, scandir,
+   semget, setjmp, shm_open, shmget, sigismember, strcasecmp, strsignal,
+   ttyname``
 
    - ``std::async()``. Not using the return value makes the call synchronous.
    - ``std::launder()``. Not using the return value usually means that the
      function interface was misunderstood by the programmer. Only the returned
      pointer is "laundered", not the argument.
    - ``std::remove()``, ``std::remove_if()`` and ``std::unique()``. The returned
      iterator indicates the boundary between elements to keep and elements to be
      removed. Not using the return value means that the information about which
      elements to remove is lost.
    - ``std::unique_ptr::release()``. Not using the return value can lead to
      resource leaks if the same pointer isn't stored anywhere else. Often,
      ignoring the ``release()`` return value indicates that the programmer
      confused the function with ``reset()``.
    - ``std::basic_string::empty()`` and ``std::vector::empty()``. Not using the
      return value often indicates that the programmer confused the function with
      ``clear()``.