Extract some duplicated code

src/audio_provider.cpp

@@ -38,6 +38,7 @@
 
 #include "audio_controller.h"
 #include "dialog_progress.h"
+#include "factory_manager.h"
 #include "frame_main.h"
 #include "main.h"
 #include "options.h"
@@ -47,6 +48,8 @@
 #include <libaegisub/log.h>
 #include <libaegisub/util.h>
 
+#include <boost/range/iterator_range.hpp>
+
 void AudioProvider::GetAudioWithVolume(void *buf, int64_t start, int64_t count, double volume) const {
 	GetAudio(buf, start, count);
 
@@ -112,10 +115,9 @@ std::unique_ptr<AudioProvider> CreateHDAudioProvider(std::unique_ptr<AudioProvid
 std::unique_ptr<AudioProvider> CreateRAMAudioProvider(std::unique_ptr<AudioProvider> source_provider, agi::BackgroundRunner *br);
 
 namespace {
-	using factory_fn = std::unique_ptr<AudioProvider> (*)(agi::fs::path const&);
 	struct factory {
 		const char *name;
-		factory_fn create;
+		std::unique_ptr<AudioProvider> (*create)(agi::fs::path const&);
 		bool hidden;
 	};
 
@@ -132,30 +134,12 @@ namespace {
 }
 
 std::vector<std::string> AudioProviderFactory::GetClasses() {
-	std::vector<std::string> list;
+	return ::GetClasses(boost::make_iterator_range(std::begin(providers), std::end(providers)));
-	for (auto const& provider : providers) {
-		if (!provider.hidden)
-			list.push_back(provider.name);
-	}
-	return list;
 }
 
 std::unique_ptr<AudioProvider> AudioProviderFactory::GetProvider(agi::fs::path const& filename) {
 	auto preferred = OPT_GET("Audio/Provider")->GetString();
-	std::vector<const factory *> sorted;
+	auto sorted = GetSorted(boost::make_iterator_range(std::begin(providers), std::end(providers)), preferred);
-	auto preferred_insertion_point = sorted.end();
-	for (auto const& provider : providers) {
-		if (provider.hidden)
-			sorted.push_back(&provider);
-		else if (preferred_insertion_point == sorted.end()) {
-			sorted.push_back(&provider);
-			preferred_insertion_point = prev(sorted.end());
-		}
-		else if (preferred == provider.name)
-			sorted.insert(preferred_insertion_point, &provider);
-		else
-			sorted.push_back(&provider);
-	}
 
 	std::unique_ptr<AudioProvider> provider;
 	bool found_file = false;

src/factory_manager.h

@@ -73,3 +73,37 @@ public:
 	}
 };
 
+namespace {
+template<typename Container>
+std::vector<std::string> GetClasses(Container const& c) {
+	std::vector<std::string> list;
+	for (auto const& provider : c) {
+		if (!provider.hidden)
+			list.push_back(provider.name);
+	}
+	return list;
+}
+
+template<typename Container>
+auto GetSorted(Container const& c, std::string const& preferred) -> std::vector<decltype(&*c.begin())> {
+	std::vector<decltype(&*c.begin())> sorted;
+	sorted.reserve(std::distance(c.begin(), c.end()));
+	size_t end_of_hidden = 0;
+	bool any_hidden = false;
+	for (auto const& provider : c) {
+		if (provider.hidden) {
+			sorted.push_back(&provider);
+			any_hidden = true;
+		}
+		else if (any_hidden && end_of_hidden == 0) {
+			end_of_hidden = sorted.size();
+			sorted.push_back(&provider);
+		}
+		else if (preferred == provider.name)
+			sorted.insert(sorted.begin() + end_of_hidden, &provider);
+		else
+			sorted.push_back(&provider);
+	}
+	return sorted;
+}
+}

src/video_provider_manager.cpp

@@ -18,6 +18,7 @@
 
 #include "video_provider_manager.h"
 
+#include "factory_manager.h"
 #include "include/aegisub/video_provider.h"
 #include "options.h"
 
@@ -25,6 +26,8 @@
 #include <libaegisub/log.h>
 #include <libaegisub/util.h>
 
+#include <boost/range/iterator_range.hpp>
+
 std::unique_ptr<VideoProvider> CreateDummyVideoProvider(agi::fs::path const&, std::string const&);
 std::unique_ptr<VideoProvider> CreateYUV4MPEGVideoProvider(agi::fs::path const&, std::string const&);
 std::unique_ptr<VideoProvider> CreateFFmpegSourceVideoProvider(agi::fs::path const&, std::string const&);
@@ -33,10 +36,9 @@ std::unique_ptr<VideoProvider> CreateAvisynthVideoProvider(agi::fs::path const&,
 std::unique_ptr<VideoProvider> CreateCacheVideoProvider(std::unique_ptr<VideoProvider>);
 
 namespace {
-	using factory_fn = std::unique_ptr<VideoProvider> (*)(agi::fs::path const&, std::string const&);
 	struct factory {
 		const char *name;
-		factory_fn create;
+		std::unique_ptr<VideoProvider> (*create)(agi::fs::path const&, std::string const&);
 		bool hidden;
 	};
 
@@ -53,30 +55,12 @@ namespace {
 }
 
 std::vector<std::string> VideoProviderFactory::GetClasses() {
-	std::vector<std::string> list;
+	return ::GetClasses(boost::make_iterator_range(std::begin(providers), std::end(providers)));
-	for (auto const& provider : providers) {
-		if (!provider.hidden)
-			list.push_back(provider.name);
-	}
-	return list;
 }
 
 std::unique_ptr<VideoProvider> VideoProviderFactory::GetProvider(agi::fs::path const& filename, std::string const& colormatrix) {
 	auto preferred = OPT_GET("Video/Provider")->GetString();
-	std::vector<const factory *> sorted;
+	auto sorted = GetSorted(boost::make_iterator_range(std::begin(providers), std::end(providers)), preferred);
-	auto preferred_insertion_point = sorted.end();
-	for (auto const& provider : providers) {
-		if (provider.hidden)
-			sorted.push_back(&provider);
-		else if (preferred_insertion_point == sorted.end()) {
-			sorted.push_back(&provider);
-			preferred_insertion_point = prev(sorted.end());
-		}
-		else if (preferred == provider.name)
-			sorted.insert(preferred_insertion_point, &provider);
-		else
-			sorted.push_back(&provider);
-	}
 
 	bool found = false;
 	bool supported = false;