playlist/Plugin: add constructors

src/playlist/PlaylistPlugin.hxx

@@ -38,20 +38,20 @@ struct PlaylistPlugin {
 	 * @return true if the plugin was initialized successfully,
 	 * false if the plugin is not available
 	 */
-	bool (*init)(const ConfigBlock &block);
+	bool (*init)(const ConfigBlock &block) = nullptr;
 
 	/**
 	 * Deinitialize a plugin which was initialized successfully.
 	 * Optional method.
 	 */
-	void (*finish)();
+	void (*finish)() = nullptr;
 
 	/**
 	 * Opens the playlist on the specified URI.  This URI has
 	 * either matched one of the schemes or one of the suffixes.
 	 */
 	std::unique_ptr<SongEnumerator> (*open_uri)(const char *uri,
-						    Mutex &mutex);
+						    Mutex &mutex) = nullptr;
 
 	/**
 	 * Opens the playlist in the specified input stream.  It has
@@ -61,11 +61,46 @@ struct PlaylistPlugin {
 	 * @parm is the input stream; the pointer will not be
 	 * invalidated when the function returns nullptr
 	 */
-	std::unique_ptr<SongEnumerator> (*open_stream)(InputStreamPtr &&is);
+	std::unique_ptr<SongEnumerator> (*open_stream)(InputStreamPtr &&is) = nullptr;
 
-	const char *const*schemes;
+	const char *const*schemes = nullptr;
-	const char *const*suffixes;
+	const char *const*suffixes = nullptr;
-	const char *const*mime_types;
+	const char *const*mime_types = nullptr;
+
+	constexpr PlaylistPlugin(const char *_name,
+				 std::unique_ptr<SongEnumerator> (*_open_uri)(const char *uri,
+									      Mutex &mutex)) noexcept
+		:name(_name), open_uri(_open_uri) {}
+
+	constexpr PlaylistPlugin(const char *_name,
+				 std::unique_ptr<SongEnumerator> (*_open_stream)(InputStreamPtr &&is)) noexcept
+		:name(_name), open_stream(_open_stream) {}
+
+	constexpr auto WithInit(bool (*_init)(const ConfigBlock &block),
+				void (*_finish)() noexcept = nullptr) noexcept {
+		auto copy = *this;
+		copy.init = _init;
+		copy.finish = _finish;
+		return copy;
+	}
+
+	constexpr auto WithSchemes(const char *const*_schemes) noexcept {
+		auto copy = *this;
+		copy.schemes = _schemes;
+		return copy;
+	}
+
+	constexpr auto WithSuffixes(const char *const*_suffixes) noexcept {
+		auto copy = *this;
+		copy.suffixes = _suffixes;
+		return copy;
+	}
+
+	constexpr auto WithMimeTypes(const char *const*_mime_types) noexcept {
+		auto copy = *this;
+		copy.mime_types = _mime_types;
+		return copy;
+	}
 };
 
 /**

src/playlist/plugins/AsxPlaylistPlugin.cxx

@@ -166,15 +166,7 @@ static const char *const asx_mime_types[] = {
 	nullptr
 };
 
-const PlaylistPlugin asx_playlist_plugin = {
+const PlaylistPlugin asx_playlist_plugin =
-	"asx",
+	PlaylistPlugin("asx", asx_open_stream)
-
+	.WithSuffixes(asx_suffixes)
-	nullptr,
+	.WithMimeTypes(asx_mime_types);
-	nullptr,
-	nullptr,
-	asx_open_stream,
-
-	nullptr,
-	asx_suffixes,
-	asx_mime_types,
-};

src/playlist/plugins/CuePlaylistPlugin.cxx

@@ -70,15 +70,7 @@ static const char *const cue_playlist_mime_types[] = {
 	nullptr
 };
 
-const PlaylistPlugin cue_playlist_plugin = {
+const PlaylistPlugin cue_playlist_plugin =
-	"cue",
+	PlaylistPlugin("cue", cue_playlist_open_stream)
-
+	.WithSuffixes(cue_playlist_suffixes)
-	nullptr,
+	.WithMimeTypes(cue_playlist_mime_types);
-	nullptr,
-	nullptr,
-	cue_playlist_open_stream,
-
-	nullptr,
-	cue_playlist_suffixes,
-	cue_playlist_mime_types,
-};

src/playlist/plugins/EmbeddedCuePlaylistPlugin.cxx

@@ -159,15 +159,6 @@ static const char *const embcue_playlist_suffixes[] = {
 	nullptr
 };
 
-const PlaylistPlugin embcue_playlist_plugin = {
+const PlaylistPlugin embcue_playlist_plugin =
-	"embcue",
+	PlaylistPlugin("embcue", embcue_playlist_open_uri)
-
+	.WithSuffixes(embcue_playlist_suffixes);
-	nullptr,
-	nullptr,
-	embcue_playlist_open_uri,
-	nullptr,
-
-	nullptr,
-	embcue_playlist_suffixes,
-	nullptr,
-};

src/playlist/plugins/ExtM3uPlaylistPlugin.cxx

@@ -147,15 +147,7 @@ static const char *const extm3u_mime_types[] = {
 	nullptr
 };
 
-const PlaylistPlugin extm3u_playlist_plugin = {
+const PlaylistPlugin extm3u_playlist_plugin =
-	"extm3u",
+	PlaylistPlugin("extm3u", extm3u_open_stream)
-
+	.WithSuffixes(extm3u_suffixes)
-	nullptr,
+	.WithMimeTypes(extm3u_mime_types);
-	nullptr,
-	nullptr,
-	extm3u_open_stream,
-
-	nullptr,
-	extm3u_suffixes,
-	extm3u_mime_types,
-};

src/playlist/plugins/FlacPlaylistPlugin.cxx

@@ -103,15 +103,6 @@ static const char *const flac_playlist_suffixes[] = {
 	nullptr
 };
 
-const PlaylistPlugin flac_playlist_plugin = {
+const PlaylistPlugin flac_playlist_plugin =
-	"flac",
+	PlaylistPlugin("flac", flac_playlist_open_stream)
-
+	.WithSuffixes(flac_playlist_suffixes);
-	nullptr,
-	nullptr,
-	nullptr,
-	flac_playlist_open_stream,
-
-	nullptr,
-	flac_playlist_suffixes,
-	nullptr,
-};

src/playlist/plugins/M3uPlaylistPlugin.cxx

@@ -69,15 +69,7 @@ static const char *const m3u_mime_types[] = {
 	nullptr
 };
 
-const PlaylistPlugin m3u_playlist_plugin = {
+const PlaylistPlugin m3u_playlist_plugin =
-	"m3u",
+	PlaylistPlugin("m3u", m3u_open_stream)
-
+	.WithSuffixes(m3u_suffixes)
-	nullptr,
+	.WithMimeTypes(m3u_mime_types);
-	nullptr,
-	nullptr,
-	m3u_open_stream,
-
-	nullptr,
-	m3u_suffixes,
-	m3u_mime_types,
-};

src/playlist/plugins/PlsPlaylistPlugin.cxx

@@ -172,15 +172,7 @@ static const char *const pls_mime_types[] = {
 	nullptr
 };
 
-const PlaylistPlugin pls_playlist_plugin = {
+const PlaylistPlugin pls_playlist_plugin =
-	"pls",
+	PlaylistPlugin("pls", pls_open_stream)
-
+	.WithSuffixes(pls_suffixes)
-	nullptr,
+	.WithMimeTypes(pls_mime_types);
-	nullptr,
-	nullptr,
-	pls_open_stream,
-
-	nullptr,
-	pls_suffixes,
-	pls_mime_types,
-};

src/playlist/plugins/RssPlaylistPlugin.cxx

@@ -165,15 +165,7 @@ static const char *const rss_mime_types[] = {
 	nullptr
 };
 
-const PlaylistPlugin rss_playlist_plugin = {
+const PlaylistPlugin rss_playlist_plugin =
-	"rss",
+	PlaylistPlugin("rss", rss_open_stream)
-
+	.WithSuffixes(rss_suffixes)
-	nullptr,
+	.WithMimeTypes(rss_mime_types);
-	nullptr,
-	nullptr,
-	rss_open_stream,
-
-	nullptr,
-	rss_suffixes,
-	rss_mime_types,
-};

src/playlist/plugins/SoundCloudPlaylistPlugin.cxx

@@ -288,17 +288,7 @@ static const char *const soundcloud_schemes[] = {
 	nullptr
 };
 
-const PlaylistPlugin soundcloud_playlist_plugin = {
+const PlaylistPlugin soundcloud_playlist_plugin =
-	"soundcloud",
+	PlaylistPlugin("soundcloud", soundcloud_open_uri)
-
+	.WithInit(soundcloud_init)
-	soundcloud_init,
+	.WithSchemes(soundcloud_schemes);
-	nullptr,
-	soundcloud_open_uri,
-	nullptr,
-
-	soundcloud_schemes,
-	nullptr,
-	nullptr,
-};
-
-

src/playlist/plugins/XspfPlaylistPlugin.cxx

@@ -211,15 +211,7 @@ static const char *const xspf_mime_types[] = {
 	nullptr
 };
 
-const PlaylistPlugin xspf_playlist_plugin = {
+const PlaylistPlugin xspf_playlist_plugin =
-	"xspf",
+	PlaylistPlugin("xspf", xspf_open_stream)
-
+	.WithSuffixes(xspf_suffixes)
-	nullptr,
+	.WithMimeTypes(xspf_mime_types);
-	nullptr,
-	nullptr,
-	xspf_open_stream,
-
-	nullptr,
-	xspf_suffixes,
-	xspf_mime_types,
-};