scoped: eliminate the raii header

CMakeLists.txt

@@ -341,7 +341,6 @@ list (
     "${CMAKE_CURRENT_SOURCE_DIR}/preprocessor.hpp"
     quaternion.cpp
     quaternion.hpp
-    raii.hpp
     rand/lcg.cpp
     rand/lcg.hpp
     rand/xorshift.cpp

job/queue.cpp

@@ -17,7 +17,7 @@
 #include "queue.hpp"
 
 #include "../parse.hpp"
-#include "../raii.hpp"
+#include "../scoped.hpp"
 
 using util::job::queue;
 
@@ -100,7 +100,7 @@ queue::loop ()
         if (m_stopping)
             return;
 
-        util::scoped_counter running_count (m_running);
+        util::scoped::increment running_count (m_running);
 
         CHECK (!m_tasks.pending->empty ());
 
@@ -111,7 +111,7 @@ queue::loop ()
             return res;
         } ();
 
-        util::scoped_function cleanup ([&, this] () {
+        util::scoped::function cleanup ([&, this] () {
             while (!m_tasks.finishing.push (todo))
                 ;
             m_doomed.release ();

memory/buffer/circular.cpp

@@ -19,8 +19,8 @@
 #include "../../debug.hpp"
 #include "../../maths.hpp"
 #include "../../posix/except.hpp"
-#include "../../raii.hpp"
 #include "../../random.hpp"
+#include "../../scoped.hpp"
 #include "../system.hpp"
 
 #include <unistd.h>
@@ -81,7 +81,9 @@ circular<ValueT>::circular (size_t bytes)
 
     // setup a desctructor for the shm data. mmap retains a reference, so do
     // this whether we succeed or fail in the next phase.
-    util::scoped_function raii ([&name] (void) { shm_unlink (name.c_str ()); });
+    util::scoped::function unlink_callback ([&name] (void) {
+        shm_unlink (name.c_str ());
+    });
 
     // embiggen to the desired size
     if (ftruncate (fd, bytes))
@@ -97,7 +99,9 @@ circular<ValueT>::circular (size_t bytes)
         posix::error::throw_code ();
 
     // preemptively setup an unmapping object in case the remapping fails
-    util::scoped_function unmapper ([this, bytes] (void) { munmap (m_begin, bytes); });
+    util::scoped::function unmapper (
+        [this, bytes] (void) noexcept { munmap (m_begin, bytes); }
+    );
 
     // overwrite the map with two adjacent copies of the memory object. this
     // must be a shared mapping for the values to propogate across segments.
@@ -111,7 +115,7 @@ circular<ValueT>::circular (size_t bytes)
         posix::error::throw_code ();
 
     // all went well, disarm the failsafe
-    unmapper.clear ();
+    unmapper.disable ();
 }
 
 

raii.hpp

@@ -1,60 +0,0 @@
-/*
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- * Copyright 2012 Danny Robson <danny@nerdcruft.net>
- */
-
-#ifndef __UTIL_RAII_HPP
-#define __UTIL_RAII_HPP
-
-#include "preprocessor.hpp"
-
-#include <functional>
-
-/// Defines a translation-unit-unique variable useful for unnamed scoped variables
-#define raii PASTE(__unique_, __COUNTER__)
-
-namespace util {
-    /// Increments a counter for the lifetime of the object
-    template <typename T>
-    struct scoped_counter {
-        explicit scoped_counter (T &_counter):
-            counter (_counter)
-        { ++counter; }
-
-        ~scoped_counter ()
-        { --counter; }
-
-        T &counter;
-    };
-
-
-    /// Executes a function upon object destruction
-    struct scoped_function {
-        explicit scoped_function (std::function<void(void)> &&_func):
-            func  (std::move (_func))
-        { ; }
-
-        ~scoped_function ()
-            { func (); }
-
-        void clear (void)
-        {
-            func = [] (void) { ; };
-        }
-
-        std::function<void(void)> func;
-    };
-}
-
-#endif

scoped.hpp

@@ -11,7 +11,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
- * Copyright 2018, Danny Robson <danny@nerdcruft.net>
+ * Copyright 2012-2018, Danny Robson <danny@nerdcruft.net>
  */
 
 #pragma once
@@ -24,7 +24,7 @@ namespace util::scoped {
     template <typename ValueT>
     class restore {
     public:
-        restore (ValueT &_target):
+        explicit restore (ValueT &_target):
             m_target (_target),
             m_value  (_target)
         { ; }
@@ -43,4 +43,68 @@ namespace util::scoped {
     //-------------------------------------------------------------------------
     template <typename ValueT>
     restore (ValueT&) -> restore<ValueT>;
+
+
+    ///////////////////////////////////////////////////////////////////////////
+    /// increments the referenced variable at construction time, and
+    /// decrements at destruction time.
+    template <typename ValueT>
+    class increment {
+    public:
+        explicit increment (ValueT &_target):
+            m_target (_target)
+        {
+            ++m_target;
         }
+
+
+        ~increment ()
+        {
+            --m_target;
+        }
+
+    private:
+        ValueT &m_target;
+    };
+
+
+    //-------------------------------------------------------------------------
+    template <typename ValueT>
+    increment (ValueT&) -> increment<ValueT>;
+
+
+    ///////////////////////////////////////////////////////////////////////////
+    /// calls a function with the supplied arguments at destruction time
+    template <typename FuncT, typename ...Args>
+    class function {
+    public:
+        explicit function (FuncT &&_function, Args&& ..._args)
+        noexcept (
+            std::is_nothrow_move_constructible_v<FuncT> &&
+            std::is_nothrow_move_constructible_v<std::tuple<Args...>>
+        ):
+            m_function (std::move (_function)),
+            m_args (std::forward<Args> (_args)...)
+        { ; }
+
+
+        void disable (void) { m_enabled = false; }
+
+
+        ~function ()
+        {
+            if (m_enabled)
+                std::apply (std::move (m_function), std::move (m_args));
+        }
+
+    private:
+        bool m_enabled = true;
+        FuncT m_function;
+        std::tuple<Args...> m_args;
+    };
+
+
+    //-------------------------------------------------------------------------
+    template <typename FuncT, typename ...Args>
+    function (FuncT &&, Args&&...) -> function<FuncT&&,Args&&...>;
+};