Use a dereference type to access smart pointer objects with ranges

Instead of taking the address of standard member functions, which is invalid.

Author: kcat

alc/alc.cpp

@@ -1781,7 +1781,7 @@ auto UpdateDeviceParams(gsl::not_null<al::Device*> device,
          * configuration in aluInitEffectPanning.
          */
         std::ranges::for_each(context->mEffectSlotClusters
-            | std::views::transform(&ContextBase::EffectSlotCluster::operator*)
+            | std::views::transform(al::dereference{})
             | std::views::join, [](EffectSlotBase &slot)
         {
             slot.mWetBuffer.clear();

alc/backends/pipewire.cpp

@@ -1408,7 +1408,7 @@ void EventManager::removeCallback(uint32_t const id) noexcept
     RemoveDevice(id);
 
     auto node_end = std::ranges::remove_if(mNodeList, [id](NodeProxy const &node) noexcept
-    { return node.mId == id; }, &std::unique_ptr<NodeProxy>::operator*);
+    { return node.mId == id; }, al::dereference{});
     mNodeList.erase(node_end.begin(), node_end.end());
 
     if(mDefaultMetadata && mDefaultMetadata->mId == id)

alc/backends/wasapi.cpp

@@ -1437,9 +1437,9 @@ FORCE_ALIGN void WasapiPlayback::mixerProc(SpatialDevice const &audio)
             {
                 auto *buffer = LPBYTE{};
                 auto size = UINT32{};
-                obj.GetBuffer(&buffer, &size);
+                std::ignore = obj.GetBuffer(&buffer, &size);
                 return buffer;
-            }, &ComPtr<ISpatialAudioObject>::operator*);
+            }, al::dereference{});
 
             if(!mResampler)
                 mDevice->renderSamples(buffers, framesToDo);

common/opthelpers.h

@@ -74,6 +74,12 @@ template<typename T>
 constexpr std::underlying_type_t<T> to_underlying(T e) noexcept
 { return static_cast<std::underlying_type_t<T>>(e); }
 
+struct dereference {
+    template<typename T> [[nodiscard]] constexpr
+    auto operator()(T&& p) const noexcept(noexcept(*std::forward<T>(p))) -> decltype(auto)
+    { return *std::forward<T>(p); }
+};
+
 /**
  * Gets a not_null<T*> from a not_null<SmartPtr<T>>, hopefully avoiding ths
  * extraneous null check from not_null's constructor.

router/alc.cpp

@@ -17,6 +17,7 @@
 
 #include "altypes.hpp"
 #include "alstring.h"
+#include "opthelpers.h"
 #include "strutils.hpp"
 
 #if HAVE_CXXMODULES
@@ -574,7 +575,7 @@ ALC_API auto ALC_APIENTRY alcOpenDevice(ALCchar const *const devicename) noexcep
                 return true;
             }
             return false;
-        }, &DriverIfacePtr::operator*);
+        }, al::dereference{});
         if(iter == DriverList.end())
         {
             LastError.store(ALC_INVALID_DEVICE);
@@ -827,7 +828,7 @@ ALC_API auto ALC_APIENTRY alcGetString(ALCdevice *const device, ALCenum const pa
                 || drv.alcIsExtensionPresent(nullptr, "ALC_ENUMERATION_EXT"))
                 DevicesList.appendDeviceList(drv.alcGetString(nullptr, ALC_DEVICE_SPECIFIER), idx);
             ++idx;
-        }, &DriverIfacePtr::operator*);
+        }, al::dereference{});
         DevicesList.finishEnumeration();
         return DevicesList.getNameData();
     }
@@ -851,7 +852,7 @@ ALC_API auto ALC_APIENTRY alcGetString(ALCdevice *const device, ALCenum const pa
                 AllDevicesList.appendDeviceList(
                     drv.alcGetString(nullptr, ALC_DEVICE_SPECIFIER), idx);
             ++idx;
-        }, &DriverIfacePtr::operator*);
+        }, al::dereference{});
         AllDevicesList.finishEnumeration();
         return AllDevicesList.getNameData();
     }
@@ -869,7 +870,7 @@ ALC_API auto ALC_APIENTRY alcGetString(ALCdevice *const device, ALCenum const pa
                 CaptureDevicesList.appendDeviceList(
                     drv.alcGetString(nullptr, ALC_CAPTURE_DEVICE_SPECIFIER), idx);
             ++idx;
-        }, &DriverIfacePtr::operator*);
+        }, al::dereference{});
         CaptureDevicesList.finishEnumeration();
         return CaptureDevicesList.getNameData();
     }
@@ -880,7 +881,7 @@ ALC_API auto ALC_APIENTRY alcGetString(ALCdevice *const device, ALCenum const pa
         {
             return drv.ALCVer >= MakeALCVer(1, 1)
                 || drv.alcIsExtensionPresent(nullptr, "ALC_ENUMERATION_EXT");
-        }, &DriverIfacePtr::operator*);
+        }, al::dereference{});
         if(iter != DriverList.end())
             return (*iter)->alcGetString(nullptr, ALC_DEFAULT_DEVICE_SPECIFIER);
         return "";
@@ -891,7 +892,7 @@ ALC_API auto ALC_APIENTRY alcGetString(ALCdevice *const device, ALCenum const pa
         auto const iter = std::ranges::find_if(DriverList, [](const DriverIface &drv)
         {
             return drv.alcIsExtensionPresent(nullptr, "ALC_ENUMERATE_ALL_EXT") != ALC_FALSE;
-        }, &DriverIfacePtr::operator*);
+        }, al::dereference{});
         if(iter != DriverList.end())
             return (*iter)->alcGetString(nullptr, ALC_DEFAULT_ALL_DEVICES_SPECIFIER);
         return "";
@@ -903,7 +904,7 @@ ALC_API auto ALC_APIENTRY alcGetString(ALCdevice *const device, ALCenum const pa
         {
             return drv.ALCVer >= MakeALCVer(1, 1)
                 || drv.alcIsExtensionPresent(nullptr, "ALC_EXT_CAPTURE");
-        }, &DriverIfacePtr::operator*);
+        }, al::dereference{});
         if(iter != DriverList.end())
             return (*iter)->alcGetString(nullptr, ALC_CAPTURE_DEFAULT_DEVICE_SPECIFIER);
         return "";
@@ -1011,7 +1012,7 @@ ALC_API auto ALC_APIENTRY alcCaptureOpenDevice(ALCchar const *const devicename,
                 return true;
             }
             return false;
-        }, &DriverIfacePtr::operator*);
+        }, al::dereference{});
         if(iter == DriverList.end())
         {
             LastError.store(ALC_INVALID_DEVICE);
@@ -1156,7 +1157,7 @@ ALC_API auto ALC_APIENTRY alcLoopbackOpenDeviceSOFT(ALCchar const *const deviceN
                 return true;
             }
             return false;
-        }, &DriverIfacePtr::operator*);
+        }, al::dereference{});
         if(iter == DriverList.end())
         {
             LastError.store(ALC_INVALID_DEVICE);

router/router.cpp

@@ -417,7 +417,7 @@ void LoadDriverList()
         return drv.ALCVer >= MakeALCVer(1, 1)
             || drv.alcIsExtensionPresent(nullptr, "ALC_ENUMERATE_ALL_EXT")
             || drv.alcIsExtensionPresent(nullptr, "ALC_ENUMERATION_EXT");
-    }, &DriverIfacePtr::operator*);
+    }, al::dereference{});
 
     /* HACK: rapture3d_oal.dll isn't likely to work if it's one distributed for
      * specific games licensed to use it. It will enumerate a Rapture3D device