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From: ThosRTanner on 21 May 2010 07:06
for instance

class Except { public: template <class T> Except &operator<<(T const
&); };

throw Except() << "went bang";

In our version of lint, this gets an error about initialising a non-
const reference with a non-lvalue.

Is this a valid error? Isn't the temporary object that gets created
immediately copied by the throw, or does it indeed go out of scope
before the throw is executed.

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From: McNepp on 25 May 2010 01:36
I think the effect you're seeing has nothing to do with code being a
"throw"-expression.
You construct a temporary object and then invoke a non-const member
function on the temporary.
There is nothing wrong with this in current C++.

My guess is that Lint is probably trained on looking for applications
of the left-shift operator and assumes that the operator function
is always declared as a free function, taking a non-const reference as
its first argument, such as:

template<typename T> Except& operator <<(Except&, const T&);

In that case, Lint would be correct with its analysis.


On 21 Mai, 23:06, ThosRTanner <ttann...(a)bloomberg.net> wrote:
> for instance
>
> class Except { public: template <class T> Except &operator<<(T const
> &); };
>
> throw Except() << "went bang";
>
> In our version of lint, this gets an error about initialising a non-
> const reference with a non-lvalue.
>
> Is this a valid error? Isn't the temporary object that gets created
> immediately copied by the throw, or does it indeed go out of scope
> before the throw is executed.

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