output/httpd: move Cast() into the class

src/output/HttpdInternal.hxx

@@ -129,6 +129,19 @@ struct HttpdOutput final : private ServerSocket {
 	HttpdOutput(EventLoop &_loop);
 	~HttpdOutput();
 
+#if GCC_CHECK_VERSION(4,6) || defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winvalid-offsetof"
+#endif
+
+	static constexpr HttpdOutput *Cast(audio_output *ao) {
+		return (HttpdOutput *)((char *)ao - offsetof(HttpdOutput, base));
+	}
+
+#if GCC_CHECK_VERSION(4,6) || defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
+
 	bool Init(const config_param &param, Error &error);
 
 	void Finish() {

src/output/HttpdOutputPlugin.cxx

@@ -146,25 +146,10 @@ httpd_output_init(const config_param &param, Error &error)
 	return result;
 }
 
-#if GCC_CHECK_VERSION(4,6) || defined(__clang__)
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Winvalid-offsetof"
-#endif
-
-static inline constexpr HttpdOutput *
-Cast(audio_output *ao)
-{
-	return (HttpdOutput *)((char *)ao - offsetof(HttpdOutput, base));
-}
-
-#if GCC_CHECK_VERSION(4,6) || defined(__clang__)
-#pragma GCC diagnostic pop
-#endif
-
 static void
 httpd_output_finish(struct audio_output *ao)
 {
-	HttpdOutput *httpd = Cast(ao);
+	HttpdOutput *httpd = HttpdOutput::Cast(ao);
 
 	httpd->Finish();
 	delete httpd;
@@ -265,7 +250,7 @@ HttpdOutput::ReadPage()
 static bool
 httpd_output_enable(struct audio_output *ao, Error &error)
 {
-	HttpdOutput *httpd = Cast(ao);
+	HttpdOutput *httpd = HttpdOutput::Cast(ao);
 
 	return httpd->Bind(error);
 }
@@ -273,7 +258,7 @@ httpd_output_enable(struct audio_output *ao, Error &error)
 static void
 httpd_output_disable(struct audio_output *ao)
 {
-	HttpdOutput *httpd = Cast(ao);
+	HttpdOutput *httpd = HttpdOutput::Cast(ao);
 
 	httpd->Unbind();
 }
@@ -319,7 +304,7 @@ static bool
 httpd_output_open(struct audio_output *ao, AudioFormat &audio_format,
 		  Error &error)
 {
-	HttpdOutput *httpd = Cast(ao);
+	HttpdOutput *httpd = HttpdOutput::Cast(ao);
 
 	assert(httpd->clients.empty());
 
@@ -347,7 +332,7 @@ HttpdOutput::Close()
 static void
 httpd_output_close(struct audio_output *ao)
 {
-	HttpdOutput *httpd = Cast(ao);
+	HttpdOutput *httpd = HttpdOutput::Cast(ao);
 
 	const ScopeLock protect(httpd->mutex);
 	httpd->Close();
@@ -379,7 +364,7 @@ HttpdOutput::SendHeader(HttpdClient &client) const
 static unsigned
 httpd_output_delay(struct audio_output *ao)
 {
-	HttpdOutput *httpd = Cast(ao);
+	HttpdOutput *httpd = HttpdOutput::Cast(ao);
 
 	if (!httpd->LockHasClients() && httpd->base.pause) {
 		/* if there's no client and this output is paused,
@@ -445,7 +430,7 @@ static size_t
 httpd_output_play(struct audio_output *ao, const void *chunk, size_t size,
 		  Error &error)
 {
-	HttpdOutput *httpd = Cast(ao);
+	HttpdOutput *httpd = HttpdOutput::Cast(ao);
 
 	if (httpd->LockHasClients()) {
 		if (!httpd->EncodeAndPlay(chunk, size, error))
@@ -462,7 +447,7 @@ httpd_output_play(struct audio_output *ao, const void *chunk, size_t size,
 static bool
 httpd_output_pause(struct audio_output *ao)
 {
-	HttpdOutput *httpd = Cast(ao);
+	HttpdOutput *httpd = HttpdOutput::Cast(ao);
 
 	if (httpd->LockHasClients()) {
 		static const char silence[1020] = { 0 };
@@ -525,7 +510,7 @@ HttpdOutput::SendTag(const Tag *tag)
 static void
 httpd_output_tag(struct audio_output *ao, const Tag *tag)
 {
-	HttpdOutput *httpd = Cast(ao);
+	HttpdOutput *httpd = HttpdOutput::Cast(ao);
 
 	httpd->SendTag(tag);
 }
@@ -533,7 +518,7 @@ httpd_output_tag(struct audio_output *ao, const Tag *tag)
 static void
 httpd_output_cancel(struct audio_output *ao)
 {
-	HttpdOutput *httpd = Cast(ao);
+	HttpdOutput *httpd = HttpdOutput::Cast(ao);
 
 	const ScopeLock protect(httpd->mutex);
 	for (auto &client : httpd->clients)