In a different thread, I proposed the following alternative to 'try_xxx':
template<typename T> T* symbol::cast_to(symbol* p) {
if (p->is<T>())
return static_cast<T*>(p);
return 0;
}
cast:
template<typename T> T& symbol:as(symbol* p) {
assert(p->is<T>())
return static_cast<T&>(*p);
}
David
On Wed, Sep 19, 2012 at 2:17 AM, Richard Guenther
<[email protected]> wrote:
> On Wed, Sep 19, 2012 at 9:29 AM, Eric Botcazou <[email protected]> wrote:
>>>
>>> The language syntax would bind the conditional into the intializer, as in
>>>
>>> if (varpool_node *vnode = (node->try_variable ()
>>> && vnode->finalized))
>>> varpool_analyze_node (vnode);
>>>
>>> which does not type-match.
>>>
>>> So, if you want the type saftey and performance, the cascade is really
>>> unavoidable.
>>
>> Just write:
>>
>> varpool_node *vnode;
>>
>> if ((vnode = node->try_variable ()) && vnode->finalized)
>> varpool_analyze_node (vnode);
>>
>> This has been the standard style for the past 2 decades and trading it for
>> cascading if's is really a bad idea.
>
> Indeed. Btw, can we not provide a specialization for dynamic_cast <>?
> This ->try_... looks awkward to me compared to the more familiar
>
> vnode = dynamic_cast <varpool_node> (node)
>
> but yeah - dynamic_cast is not a template ... (but maybe there is some
> standard library piece that mimics it?).
>
> Richard.
>
>> --
>> Eric Botcazou
