From: Gareth McCaughan <gmccaughan@synaptics-uk.com>
To: Ivan Molella <i.molella@reply.it>
Cc: gcc@gcc.gnu.org
Subject: Re: compiler confusion?
Date: Thu, 24 Apr 2003 15:12:00 -0000 [thread overview]
Message-ID: <200304241411.01100.gmccaughan@synaptics-uk.com> (raw)
Here's a stripped-down version of your code that exhibits
the same problem.
struct A {
A(bool x) {}
};
struct C {
void f();
};
static int g() { return 1; }
void C::f() {
A(g() == 100);
}
Here's what I think is going on: the compiler is seeing
that line "A(g() == 100);" as a declaration of a function
called g, returning a value of type A. The same as if it said
"A g() == 100;". And, of course, when it gets to the "==",
that stops making any sense :-).
I'm not enough of a C++ standards guru to know whether
this behaviour is (1) allowed and/or (2) required. It's
weird, certainly, but there are other almost equally
ludicrous interpretations that *are* required by the
standard. For instance, here's an example from Scott Meyers's
"Effective STL".
ifstream dataFile("ints.dat");
list<int> data(istream_iterator<int>(dataFile),
istream_iterator<int>());
Perhaps contrary to appearances, what this does is
to declare a function called "data" taking two
arguments: the first is of type istream_iterator<int>
and is named "dataFile", and the second is of type
"pointer to function from void to istream_iterator<int>"
and has no name. :-)
--
g
next reply other threads:[~2003-04-24 13:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-04-24 15:12 Gareth McCaughan [this message]
2003-04-25 9:00 ` wilson k.j
-- strict thread matches above, loose matches on Subject: below --
2003-04-23 16:03 Ivan Molella
2003-04-23 15:46 Ivan Molella
2003-04-23 13:29 Ivan Molella
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