🚀 go-pugleaf

In article <1aa7sjINN2rj@agate.berkeley.edu> faustus@ygdrasil.cs.berkeley.edu (Wayne A. Christopher) writes:
>The following program causes an assertion failure in the ofstream
>code.  I can't see what is wrong...  Any ideas?  I don't have 2.2 yet
>so I haven't tested it there.

The crash also occurs with libg++ 2.2.

>#include <fstream.h>
>
>static ofstream ofile;
>
>main()
>{
>    ofile = ofstream("outputfile");    
>    ofile << "Here is some output\n";
>}

Since there is no assignment operator for class ofstream, or for any of
its baseclasses, the assignment of ofstream("outputfile") does a
memberwise copy of fields to ofile.  Since the right-side ojbect is a
temporary object, it is then destroyed, leaving ofile's members pointing
to garbage.  It is then only a matter of time until the program blows up.
Assigning one ofstream to another is not valid.

The iostream library provided with cfront 2.1 handles this by making
ios::operator= a private member, which makes assignment of iostream
objects a compile-time error (except for classes like
{i,o,io}stream_withassign, which provide an assignment operator).
I think that libg++ should either do the same, or provide a correct
assignment operator.  Same for the copy constructor.

libg++ does not provide the iostream_withassign classes.  Should it?
I don't know.

You can probably get the effect you wanted by saying

	ofile.open("outputfile");





--
Joe Buck	jbuck@ohm.berkeley.edu