Newsgroups: comp.std.c++
Path: utzoo!utgpu!news-server.csri.toronto.edu!torsqnt!geac!alias!rae
From: rae@alias.com (Reid Ellis)
Subject: Re: Assignment operators return lvalues / classes and types
Message-ID: <1991Apr27.161946.953@alias.com>
Keywords: assignment, lvalue, class, type
Sender: news@alias.com (USENET News)
Organization: Alias Research, Inc. Toronto ON Canada
References: <950@edg1.UUCP> <1991Apr24.184018.23427@kestrel.edu> <1991Apr25.030006.5849@csi.uottawa.ca>
Date: Sat, 27 Apr 91 16:19:46 GMT

Martin Hitz <hitz@sim5.csi.uottawa.ca> writes:
>struct X { int i; };
>X f() { X x; return x; }
>main()
>{
>	int i = f().i;	// OK
>	X x;
>	f() = x;	// !OK
>}
>
>f() does NOT return an lvalue

I would have thought that f() *does* return an lvalue, albeit in the
form of a temporary variable.  Note that the following *does* work:

	#include <iostream.h>

	struct X { int i; };
	X f() { X x; x.i=12; return x; }
	main()
	{
		X x;

		x.i = 23;

		X & xref = f();
		cout << "xref is " << xref.i << '\n';
		xref = x;
		cout << "x is " << x.i << ", while xref is now " << xref.i << '\n';
	}

The output from this is

	xref is 12
	x is 23, while xref is now 23

So it would seem that your [and my!] version of cfront is broken..

					Reid
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