output/Multiple: migrate from class Error to C++ exceptions

src/output/MultipleOutputs.cxx

@@ -58,14 +58,8 @@ try {
 	AudioOutput *output = audio_output_new(event_loop, block,
 					       mixer_listener,
 					       pc, error);
-	if (output == nullptr) {
-		if (block.line > 0)
-			FormatFatalError("line %i: %s",
-					 block.line,
-					 error.GetMessage());
-		else
-			FatalError(error);
-	}
+	if (output == nullptr)
+		throw std::runtime_error(error.GetMessage());
 
 	return output;
 } catch (const std::runtime_error &e) {
@@ -192,32 +186,27 @@ MultipleOutputs::SetReplayGainMode(ReplayGainMode mode)
 		ao->SetReplayGainMode(mode);
 }
 
-bool
-MultipleOutputs::Play(MusicChunk *chunk, Error &error)
+void
+MultipleOutputs::Play(MusicChunk *chunk)
 {
 	assert(buffer != nullptr);
 	assert(pipe != nullptr);
 	assert(chunk != nullptr);
 	assert(chunk->CheckFormat(input_audio_format));
 
-	if (!Update()) {
+	if (!Update())
 		/* TODO: obtain real error */
-		error.Set(output_domain, "Failed to open audio output");
-		return false;
-	}
+		throw std::runtime_error("Failed to open audio output");
 
 	pipe->Push(chunk);
 
 	for (auto ao : outputs)
 		ao->LockPlay();
-
-	return true;
 }
 
-bool
+void
 MultipleOutputs::Open(const AudioFormat audio_format,
-		      MusicBuffer &_buffer,
-		      Error &error)
+		      MusicBuffer &_buffer)
 {
 	bool ret = false, enabled = false;
 
@@ -251,17 +240,16 @@ MultipleOutputs::Open(const AudioFormat audio_format,
 			ret = true;
 	}
 
-	if (!enabled)
-		error.Set(output_domain, "All audio outputs are disabled");
-	else if (!ret)
-		/* TODO: obtain real error */
-		error.Set(output_domain, "Failed to open audio output");
-
-	if (!ret)
+	if (!enabled) {
 		/* close all devices if there was an error */
 		Close();
-
-	return ret;
+		throw std::runtime_error("All audio outputs are disabled");
+	} else if (!ret) {
+		/* close all devices if there was an error */
+		Close();
+		/* TODO: obtain real error */
+		throw std::runtime_error("Failed to open audio output");
+	}
 }
 
 /**

src/output/MultipleOutputs.hxx

@@ -118,13 +118,13 @@ public:
 	/**
 	 * Opens all audio outputs which are not disabled.
 	 *
+	 * Throws #std::runtime_error on error.
+	 *
 	 * @param audio_format the preferred audio format
 	 * @param _buffer the #music_buffer where consumed #MusicChunk objects
 	 * should be returned
-	 * @return true on success, false on failure
 	 */
-	bool Open(const AudioFormat audio_format, MusicBuffer &_buffer,
-		  Error &error);
+	void Open(const AudioFormat audio_format, MusicBuffer &_buffer);
 
 	/**
 	 * Closes all audio outputs.
@@ -143,11 +143,11 @@ public:
 	 * Enqueue a #MusicChunk object for playing, i.e. pushes it to a
 	 * #MusicPipe.
 	 *
+	 * Throws #std::runtime_error on error (all closed then).
+	 *
 	 * @param chunk the #MusicChunk object to be played
-	 * @return true on success, false if no audio output was able to play
-	 * (all closed then)
 	 */
-	bool Play(MusicChunk *chunk, Error &error);
+	void Play(MusicChunk *chunk);
 
 	/**
 	 * Checks if the output devices have drained their music pipe, and