Remove unused scheduler_op::data_ and data()

Author: vinniefalco

src/corosio/src/detail/epoll/op.hpp

@@ -149,10 +149,7 @@ struct epoll_op : scheduler_op
     epoll_socket_impl* socket_impl_ = nullptr;
     epoll_acceptor_impl* acceptor_impl_ = nullptr;
 
-    epoll_op()
-    {
-        data_ = this;
-    }
+    epoll_op() = default;
 
     void reset() noexcept
     {

src/corosio/src/detail/iocp/overlapped_op.hpp

@@ -75,7 +75,6 @@ struct overlapped_op
     explicit overlapped_op(func_type func) noexcept
         : scheduler_op(func)
     {
-        data_ = this;
         reset_overlapped();
     }
 

src/corosio/src/detail/posix/resolver_service.cpp

@@ -324,10 +324,7 @@ class posix_resolver_impl
         std::atomic<bool> cancelled{false};
         std::optional<std::stop_callback<canceller>> stop_cb;
 
-        resolve_op()
-        {
-            data_ = this;
-        }
+        resolve_op() = default;
 
         void reset() noexcept;
         void operator()() override;
@@ -370,10 +367,7 @@ class posix_resolver_impl
         std::atomic<bool> cancelled{false};
         std::optional<std::stop_callback<canceller>> stop_cb;
 
-        reverse_resolve_op()
-        {
-            data_ = this;
-        }
+        reverse_resolve_op() = default;
 
         void reset() noexcept;
         void operator()() override;

src/corosio/src/detail/scheduler_op.hpp

@@ -18,8 +18,6 @@
 
 namespace boost::corosio::detail {
 
-class win_scheduler;
-
 /** Base class for completion handlers using function pointer dispatch.
 
     Handlers are continuations that execute after an asynchronous
@@ -95,18 +93,6 @@ class scheduler_op : public intrusive_queue<scheduler_op>::node
             func_(nullptr, this, 0, 0);
     }
 
-    /** Returns the user-defined data pointer.
-
-        Derived classes may set this to store auxiliary data
-        such as a pointer to the most-derived object.
-
-        @return The user-defined data pointer, or `nullptr` if not set.
-    */
-    void* data() const noexcept
-    {
-        return data_;
-    }
-
     virtual ~scheduler_op() = default;
 
 protected:
@@ -131,7 +117,6 @@ class scheduler_op : public intrusive_queue<scheduler_op>::node
     }
 
     func_type func_;
-    void* data_ = nullptr;
 };
 
 //------------------------------------------------------------------------------

src/corosio/src/detail/select/op.hpp

@@ -134,10 +134,7 @@ struct select_op : scheduler_op
     select_socket_impl* socket_impl_ = nullptr;
     select_acceptor_impl* acceptor_impl_ = nullptr;
 
-    select_op()
-    {
-        data_ = this;
-    }
+    select_op() = default;
 
     void reset() noexcept
     {