Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!milano!cadillac!puma!vaughan
From: vaughan@puma.cad.mcc.com (Paul Vaughan)
Newsgroups: comp.lang.c++
Subject: conversions
Message-ID: <7633@cadillac.CAD.MCC.COM>
Date: 11 Apr 90 20:50:25 GMT
Sender: news@cadillac.CAD.MCC.COM
Lines: 34


The following program compiles cleanly under g++-1.37.1, but gets
three errors under cfront (Sun CC, actually).

---------------------------
class Int {
  int i;
public:
  Int(int j) : i(j) {}
  Int(Int& I) { i = I.i; }
  operator int() { return i; }
  operator int&() { return i; }
};

main() {
  Int i = 4;
  i += i;               // line 29
}

------------------------
CC -c convert.cc
CC  convert.cc:
"convert.cc", line 30: error: ambiguous conversion of Int
"convert.cc", line 30: error: ambiguous conversion of Int
"convert.cc", line 30: error: bad operand types Int  Int  for +=
3 errors

Any comments on why CC generates these errors, and whether or not this
is the right thing to do?  I realize that a class that works Exactly
like an int for both reading and assignment probably isn't very
useful, but should I be able to do it this way?

 Paul Vaughan, MCC CAD Program | ARPA: vaughan@mcc.com | Phone: [512] 338-3639
 Box 200195, Austin, TX 78720  | UUCP: ...!cs.utexas.edu!milano!cadillac!vaughan