-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Wednesday 02 April 2008 16:46 pm, klaus triendl wrote:
Phil Endecott schrieb:
i.e. LockableRef contains a reference to the mutex and one element of its "parent" Lockable<>, and presents the same interface as a data-full Lockable<>.
But because Lockable and LockableRef aren't actually the same type, I can't write
void start_updater(Lockable<int> i);
and use it with both.
Is this something that you have thought about?
Well, I didn't think about this one. But what do you think of the following?
<code> template<typename T_type, typename T_mutex> struct lockable //: ... { // ...
// return a lockable_ref, see below lockable_ref<std::tr1::remove_extent<T_type>, T_mutex> operator [](std::size_t idx) { return lockable_ref<std::tr1::remove_extent<T_type>, T_mutex>(access_volatile()[idx], mutex()); } };
This would only support array-like types. Are you familiar with the aliasing constructor of shared_ptr? I put something similar in poet::monitor_ptr, but it's only in cvs at the moment. Anyways, it's a more general solution to this kind of situation, although it doesn't provide much of a safeguard against misuse. Anyways, your example snippet would look something like this: <code> void start_updater(poet::monitor_ptr<int> i) { //... } poet::monitor_ptr<array<int, 100> > values; poet::monitor_ptr<int> one_value; //... for (int i=0; i<100; ++i) { start_updater(poet::monitor_ptr<int>(values, &values->at(i))); } start_updater(one_value); </code> - -- Frank -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFH9N2N5vihyNWuA4URAieWAKDPq4o2VKHIoRKeiBZmz3gN6N7VIgCg5MgQ PnAdePswe+M7crNq7SLcOlk= =IC+K -----END PGP SIGNATURE-----