[Bug c++/36587] New: Feature: add warning for constructor call with discarded return.

["kkylheku at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

This patch implements a ``-Wunused-objects'' warning which is triggered if a
constructor is called, and the returned object is thrown away.

This can happen by accident when a declaration for an object accidentally omits
a name. For instance:

  {
    trace_class ("foo", ...);
    //         ^ missing name
  }

Whereas it is common for C++ function calls to discard returned objects,
discarding the result of an explicit constructor call is most likely a mistake.

I developed a patch against GCC 4.1.1 for this (because that's the compiler
currently used by my organization). The patch doesn't include a documentation
update, just code.


-- 
           Summary: Feature: add warning for constructor call with discarded
                    return.
           Product: gcc
           Version: 4.1.1
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kkylheku at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36587