[cpp-threads] Fixing the thread type

[Peter Dimov]

Ben Hutchings wrote:

> As you may know, Pete Becker proposed standardisation of the
> Boost.Thread library in N1907.  I know Andrei Alexandrescu has some
> serious objections to this library and Kevlin Henney has a much richer
> thread library in mind.  However, in the absence of a concrete proposal
> from them or a larger group of us (and, I would imagine, implementation
> experience) it seems likely to me that something like Boost.Thread will
> be standardised.  Therefore I would like to propose, as a fallback, some
> cleaning up of the interface described in N1907.  Here's my first draft:
> <http://womble.decadentplace.org.uk/c++/std-thread-fix.html>.

For reference:

class thread
    {
public:
    thread();
    template <class Func>
        explicit thread(Func func);

    bool operator== (const thread& other) const;
    bool operator!= (const thread& other) const
        {return !operator==(other); }
    bool is_current () const;

    void join();
    static void sleep(const xtime& xt);
    static void yield();

    // exposition only
private:

    // not implemented
    thread(const thread&);
    thread& operator= (const thread&);
    };



My counterproposal is:

// everything in namespace std::tr2

class thread_handle;

// thread_handle is CopyConstructible, EqualityComparable, 
LessThanComparable,
// OutputStreamable (for logging/debugging)
// DefaultConstructible? TBD

template<class F> thread_handle create_thread( F f );
thread_handle current_thread();

void join_thread( thread_handle const & th );
bool try_join_thread( thread_handle const & th );
bool timed_join_thread( thread_handle const & th, xtime const & xt );

// void cancel_thread( thread_handle const & th ); // maybe one day

Substitute thread_/_thread with namespace thread:: according to taste. :-)