[cppcheck] use const for several variables

src/decoder/plugins/SndfileDecoderPlugin.cxx

@@ -56,8 +56,8 @@ struct SndfileInputStream {
 static sf_count_t
 sndfile_vio_get_filelen(void *user_data)
 {
-	SndfileInputStream &sis = *(SndfileInputStream *)user_data;
-	const InputStream &is = sis.is;
+	const auto &sis = *(SndfileInputStream *)user_data;
+	const auto &is = sis.is;
 
 	if (!is.KnownSize())
 		return -1;
@@ -120,8 +120,8 @@ sndfile_vio_write([[maybe_unused]] const void *ptr,
 static sf_count_t
 sndfile_vio_tell(void *user_data)
 {
-	SndfileInputStream &sis = *(SndfileInputStream *)user_data;
-	const InputStream &is = sis.is;
+	const auto &sis = *(SndfileInputStream *)user_data;
+	const auto &is = sis.is;
 
 	return is.GetOffset();
 }

src/decoder/plugins/WavpackDecoderPlugin.cxx

@@ -398,21 +398,21 @@ WavpackInput::ReadBytes(void *data, size_t bcount)
 static int64_t
 wavpack_input_get_pos(void *id)
 {
-	WavpackInput &wpi = *wpin(id);
+	const auto &wpi = *wpin(id);
 	return wpi.GetPos();
 }
 
 static int
 wavpack_input_set_pos_abs(void *id, int64_t pos)
 {
-	WavpackInput &wpi = *wpin(id);
+	auto &wpi = *wpin(id);
 	return wpi.SetPosAbs(pos);
 }
 
 static int
 wavpack_input_set_pos_rel(void *id, int64_t delta, int mode)
 {
-	WavpackInput &wpi = *wpin(id);
+	auto &wpi = *wpin(id);
 	return wpi.SetPosRel(delta, mode);
 }
 
@@ -421,21 +421,21 @@ wavpack_input_set_pos_rel(void *id, int64_t delta, int mode)
 static uint32_t
 wavpack_input_get_pos(void *id)
 {
-	WavpackInput &wpi = *wpin(id);
+	const auto &wpi = *wpin(id);
 	return wpi.GetPos();
 }
 
 static int
 wavpack_input_set_pos_abs(void *id, uint32_t pos)
 {
-	WavpackInput &wpi = *wpin(id);
+	auto &wpi = *wpin(id);
 	return wpi.SetPosAbs(pos);
 }
 
 static int
 wavpack_input_set_pos_rel(void *id, int32_t delta, int mode)
 {
-	WavpackInput &wpi = *wpin(id);
+	auto &wpi = *wpin(id);
 	return wpi.SetPosRel(delta, mode);
 }
 
@@ -444,7 +444,7 @@ wavpack_input_set_pos_rel(void *id, int32_t delta, int mode)
 static int
 wavpack_input_push_back_byte(void *id, int c)
 {
-	WavpackInput &wpi = *wpin(id);
+	auto &wpi = *wpin(id);
 	return wpi.PushBackByte(c);
 }
 
@@ -453,7 +453,7 @@ wavpack_input_push_back_byte(void *id, int c)
 static int64_t
 wavpack_input_get_length(void *id)
 {
-	WavpackInput &wpi = *wpin(id);
+	const auto &wpi = *wpin(id);
 	return wpi.GetLength();
 }
 
@@ -462,7 +462,7 @@ wavpack_input_get_length(void *id)
 static uint32_t
 wavpack_input_get_length(void *id)
 {
-	WavpackInput &wpi = *wpin(id);
+	const auto &wpi = *wpin(id);
 	return wpi.GetLength();
 }
 
@@ -471,7 +471,7 @@ wavpack_input_get_length(void *id)
 static int
 wavpack_input_can_seek(void *id)
 {
-	WavpackInput &wpi = *wpin(id);
+	const auto &wpi = *wpin(id);
 	return wpi.CanSeek();
 }
 

src/event/PollGroupPoll.cxx

@@ -63,7 +63,7 @@ PollGroupPoll::Remove(int fd) noexcept
 {
 	auto item_iter = items.find(fd);
 	assert(item_iter != items.end());
-	auto &item = item_iter->second;
+	const auto &item = item_iter->second;
 	size_t index = item.index;
 	size_t last_index = poll_events.size() - 1;
 	if (index != last_index) {