[Bug c++/36696] New: Default constructor instance definition with empty argument list quietly ignored

[Bug c++/36696] New: Default constructor instance definition with empty argument list quietly ignored

[mike dot allen at facsim dot org]

Compile following with -Wall:

#include <iostream>

class Raii
{
public:
    Raii () throw ()
    {
        std::cout << "Raii::Raii () called..." << std::endl;
    }
public:
    ~Raii () throw ()
    {
        std::cout << "Raii::~Raii () called..." << std:: endl;
    }
};

int main (int /*argc*/, char** /*argv*/)
{
    Raii raii ();
    std::cout << "Inside main ()..." << std::endl;
    return 0;
}

This compiles with no errors.  When the result is executed, you get the
following output:

Inside main ()...

And that's all.  The compiler quietly ignored the declaration of an Raii
instance with an empty argument list.  No warnings, no errors, nothing.

If the empty argument list is removed, that is, if you have:

#include <iostream>

class Raii
{
public:
    Raii () throw ()
    {
        std::cout << "Raii::Raii () called..." << std::endl;
    }
public:
    ~Raii () throw ()
    {
        std::cout << "Raii::~Raii () called..." << std:: endl;
    }
};

int main (int /*argc*/, char** /*argv*/)
{
    Raii raii;
    std::cout << "Inside main ()..." << std::endl;
    return 0;
}

Then you get the expected output:

Raii::Raii () called...
Inside main ()...
Raii::~Raii () called...

Is this correct behavior?

g++ -v:
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v
--enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr
--enable-shared --with-system-zlib --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix --enable-nls
--with-gxx-include-dir=/usr/include/c++/4.2 --program-suffix=-4.2
--enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr
--enable-targets=all --enable-checking=release --build=i486-linux-gnu
--host=i486-linux-gnu --target=i486-linux-gnu
Thread model: posix
gcc version 4.2.3 (Ubuntu 4.2.3-2ubuntu7)


-- 
           Summary: Default constructor instance definition with empty
                    argument list quietly ignored
           Product: gcc
           Version: 4.2.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mike dot allen at facsim dot org
GCC target triplet: i486-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36696

[Bug c++/36696] Default constructor instance definition with empty argument list quietly ignored

[mike dot allen at facsim dot org]

------- Comment #1 from mike dot allen at facsim dot org  2008-07-02 14:41 -------
Is the line:

Raii raii();

being interpreted by the compiler as the declaration of a function that takes
no arguments and returns a Raii instance?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36696

[Bug c++/36696] Default constructor instance definition with empty argument list quietly ignored

[dseketel at redhat dot com]

------- Comment #2 from dseketel at redhat dot com  2008-07-02 21:09 -------
Yes, foo bar (); is indeed the declaration of a function bar of type foo that
takes no arguments in parameter.

I believe gcc is right there.


-- 

dseketel at redhat dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dseketel at redhat dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36696

[Bug c++/36696] Default constructor instance definition with empty argument list quietly ignored

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2008-07-02 21:16 -------
This is an ambiguous in the C++ standard that is resolved via making it a
function declaration.
That is:
    Raii raii ();

Is declaring a function, raii, that returns a Raii type.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36696