[boost] [thread] is there an interest on this unique_to_shared_mutex_adapter class?

From: vicente.botet (vicente.botet_at_[hidden])
Date: 2008-05-09 08:40:59

Hi,

boost::mutex is a model of Lockable but do not conforms to a SharedLockable, 
UpgradeLockable concepts.
Do you think that we can make an adapter of boost::mutex to be a model of 
SharedLockable, UpgradeLockable or there is something I've missed?

Consider the following situation:

template <class SharedLockable>
void f(SharedLockable&l) const { /*< externally locked generic const 
function>*/
    boost::shared_lock<Lokable> lock(smtx);
    // ... some read operations
 }

 // elsewhere
 boost::mutex mtx; /*< the external user prefer to use a mutex and not a 
shared_mutex >*/

 //
 {
     shared_lockable_adapter smtx(mtx); /*< mtx must be adapted to a 
shared_mutex >*/
     f(smtx);    /*< to call f without compiler errors >*/
     //..
 }

Do you know a simple way to achieve this?
Do you think this adapter could be of general use?

The class shared_lockable_adapter can be defined as follows:

template <typename Lockable>
class shared_lockable_adapter
{
    shared_lockable_adapter(Lockable& mtx): mtx_(mtx) {}
    ~shared_lockable_adapter() {}
    void lock_shared() {mtx_.lock();}
    void unlock_shared() {mtx_.unlock();}
    bool try_lock_shared() { return mtx_.try_lock();}
    void lock() {mtx_.lock();}
    void unlock() {mtx_.unlock();}
    bool try_lock() { return mtx_.try_lock();}
    // other functions ....
private:
    Lockable& mtx_;
};

Comments?
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