Re: A non-const reference may only be bound to an lvalue?

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Thanks David,


I agree and understand from you that from Spec we should not bind a rvalue
to a non-const reference, but in Visual Studio 2008, the following code can
compile and no warning messages. Any comments?

struct X {

};

void f(X& x) {};

void g()
{
f(X());
}



"David Wilkinson" wrote:

Doug Harrison [MVP] wrote:
The thing is, that's got little to do with the typical desired usage, which
is to permit:

void f(X&);

void g()
{
f(X());
}

There are legitimate reasons to want to do that, but I've come to accept it
shouldn't be allowed for this reason. Suppose you have a class:

Doug:

Yes, this is the kind of situation where this has bitten me. In my case,
X was a function object with some modifiable internal state that was
used in f, but was not needed in g after f returned. This was
cross-platform code (developed on VC7.1), and just one of the other
compilers we were using a few years ago would not accept it (now, I
think, most will not).

Of course it is easily fixed by doing

void g()
{
X x;
f(x);
}

--
David Wilkinson
Visual C++ MVP



regards,
George
.

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