Add range adaptor for filtering to a specific subclass from a heterogeneous range

This makes looping over the subtitle file and parsed dialogue lines less
awkward in many cases.

aegisub/build/libaegisub/libaegisub.vcxproj

@@ -92,6 +92,7 @@
     <ClInclude Include="$(SrcDir)include\libaegisub\background_runner.h" />
     <ClInclude Include="$(SrcDir)include\libaegisub\color.h" />
     <ClInclude Include="$(SrcDir)include\libaegisub\spellchecker.h" />
+    <ClInclude Include="..\..\libaegisub\include\libaegisub\of_type_adaptor.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(SrcDir)windows\lagi_pre.cpp">

aegisub/build/libaegisub/libaegisub.vcxproj.filters

@@ -134,6 +134,9 @@
     <ClInclude Include="$(SrcDir)common\parser.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\libaegisub\include\libaegisub\of_type_adaptor.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(SrcDir)windows\lagi_pre.cpp">

aegisub/libaegisub/include/libaegisub/of_type_adaptor.h

@@ -0,0 +1,69 @@
+// Copyright (c) 2011, Thomas Goyne <plorkyeran@aegisub.org>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+// Aegisub Project http://www.aegisub.org/
+
+#include <boost/range/adaptor/filtered.hpp>
+#include <boost/range/adaptor/transformed.hpp>
+
+namespace agi {
+	namespace of_type_detail {
+		using namespace boost::adaptors;
+
+		/// Tag type returned from of_type<T>() to select the operator| overload
+		template<class T> struct of_type_tag {};
+
+		/// Take the address of a value and dynamic_cast it to Type*
+		template<class Type>
+		struct cast_to {
+			typedef Type *result_type;
+
+			template<class InType> Type *operator()(InType &ptr) const {
+				return dynamic_cast<Type *>(&ptr);
+			}
+
+			template<class InType> Type *operator()(InType *ptr) const {
+				return dynamic_cast<Type *>(ptr);
+			}
+		};
+
+		template<class Type>
+		inline bool not_null(Type *ptr) {
+			return !!ptr;
+		}
+
+		// Defined here for ADL reasons, since we don't want the tag type in
+		// the top-level agi namespace (and it lets us get away with the using
+		// namespace above)
+		template<class Rng, class Type>
+		inline auto operator|(Rng& r, of_type_tag<Type>)
+			-> decltype(r | transformed(cast_to<Type>()) | filtered(not_null<Type>))
+		{
+			return r | transformed(cast_to<Type>()) | filtered(not_null<Type>);
+		}
+
+		// const overload of the above
+		template<class Rng, class Type>
+		inline auto operator|(Rng const& r, of_type_tag<Type>)
+			-> decltype(r | transformed(cast_to<const Type>()) | filtered(not_null<const Type>))
+		{
+			return r | transformed(cast_to<const Type>()) | filtered(not_null<const Type>);
+		}
+	}
+
+	template<class T>
+	inline of_type_detail::of_type_tag<T> of_type() {
+		return of_type_detail::of_type_tag<T>();
+	}
+}

aegisub/src/ass_file.cpp

@@ -58,6 +58,8 @@
 #include "text_file_writer.h"
 #include "utils.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 namespace std {
 	template<>
 	void swap(AssFile &lft, AssFile &rgt) {
@@ -399,20 +401,17 @@ void AssFile::GetResolution(int &sw,int &sh) const {
 
 wxArrayString AssFile::GetStyles() const {
 	wxArrayString styles;
-	for (auto const& line : Line) {
-		if (const AssStyle *curstyle = dynamic_cast<const AssStyle*>(&line))
-			styles.Add(curstyle->name);
-	}
+	for (auto style : Line | agi::of_type<AssStyle>())
+		styles.push_back(style->name);
 	return styles;
 }
 
 AssStyle *AssFile::GetStyle(wxString const& name) {
-	for (auto& line : Line) {
-		AssStyle *curstyle = dynamic_cast<AssStyle*>(&line);
-		if (curstyle && curstyle->name == name)
-			return curstyle;
+	for (auto style : Line | agi::of_type<AssStyle>()) {
+		if (style->name == name)
+			return style;
 	}
-	return NULL;
+	return nullptr;
 }
 
 void AssFile::AddToRecent(wxString const& file) const {

aegisub/src/base_grid.cpp

@@ -63,6 +63,8 @@
 #include "video_context.h"
 #include "video_slider.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 enum {
 	GRID_SCROLLBAR = 1730,
 	MENU_SHOW_COL = 1250 // Needs 15 IDs after this
@@ -278,12 +280,10 @@ void BaseGrid::UpdateMaps(bool preserve_selected_rows) {
 	index_line_map.clear();
 	line_index_map.clear();
 
-	for (auto& line : context->ass->Line) {
-		if (AssDialogue *curdiag = dynamic_cast<AssDialogue*>(&line)) {
-			line_index_map[curdiag] = (int)index_line_map.size();
-			index_line_map.push_back(curdiag);
-		}
-	}
+	for (auto curdiag : context->ass->Line | agi::of_type<AssDialogue>()) {
+		line_index_map[curdiag] = (int)index_line_map.size();
+		index_line_map.push_back(curdiag);
+}
 
 	if (preserve_selected_rows) {
 		Selection sel;

aegisub/src/command/edit.cpp

@@ -62,6 +62,10 @@
 #include "../utils.h"
 #include "../video_context.h"
 
+#include <boost/range/adaptor/reversed.hpp>
+
+#include <libaegisub/of_type_adaptor.h>
+
 namespace {
 	using cmd::Command;
 /// @defgroup cmd-edit Editing commands.
@@ -163,14 +167,10 @@ void paste_lines(agi::Context *c, bool paste_over) {
 
 template<class T>
 T get_value(AssDialogue const& line, int blockn, T initial, wxString const& tag, wxString alt = wxString()) {
-	for (int i = blockn; i >= 0; i--) {
-		AssDialogueBlockOverride *ovr = dynamic_cast<AssDialogueBlockOverride*>(line.Blocks[i]);
-		if (!ovr) continue;
-
-		for (int j = (int)ovr->Tags.size() - 1; j >= 0; j--) {
-			if (ovr->Tags[j]->Name == tag || ovr->Tags[j]->Name == alt) {
-				return ovr->Tags[j]->Params[0]->Get<T>(initial);
-			}
+	for (auto ovr : line.Blocks | boost::adaptors::reversed | agi::of_type<AssDialogueBlockOverride>()) {
+		for (auto tag : ovr->Tags | boost::adaptors::reversed) {
+			if (tag->Name == tag || tag->Name == alt)
+				return tag->Params[0]->Get<T>(initial);
 		}
 	}
 	return initial;
@@ -485,9 +485,8 @@ struct edit_find_replace : public Command {
 static void copy_lines(agi::Context *c) {
 	wxString data;
 	SubtitleSelection sel = c->selectionController->GetSelectedSet();
-	for (auto& line : c->ass->Line) {
-		AssDialogue *diag = dynamic_cast<AssDialogue*>(&line);
-		if (diag && sel.count(diag)) {
+	for (auto diag : c->ass->Line | agi::of_type<AssDialogue>()) {
+		if (sel.count(diag)) {
 			if (!data.empty())
 				data += "\r\n";
 			data += diag->GetEntryData();
@@ -505,10 +504,7 @@ static void delete_lines(agi::Context *c, wxString const& commit_message) {
 	AssDialogue *new_active = 0;
 	bool hit_active = false;
 
-	for (auto& line : c->ass->Line) {
-		AssDialogue *diag = dynamic_cast<AssDialogue*>(&line);
-		if (!diag) continue;
-
+	for (auto diag : c->ass->Line | agi::of_type<AssDialogue>()) {
 		if (diag == active) {
 			hit_active = true;
 			if (new_active) break;

aegisub/src/command/time.cpp

@@ -54,6 +54,8 @@
 #include "../subs_grid.h"
 #include "../video_context.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 namespace {
 	using cmd::Command;
 
@@ -71,10 +73,7 @@ namespace {
 			if (sel.size() < 2) return false;
 
 			size_t found = 0;
-			for (auto& line : c->ass->Line) {
-				AssDialogue *diag = dynamic_cast<AssDialogue*>(&line);
-				if (!diag) continue;
-
+			for (auto diag : c->ass->Line | agi::of_type<AssDialogue>()) {
 				if (sel.count(diag)) {
 					++found;
 					if (found == sel.size())

aegisub/src/dialog_attachments.cpp

@@ -53,6 +53,8 @@
 #include "main.h"
 #include "utils.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 enum {
 	BUTTON_ATTACH_FONT = 1300,
 	BUTTON_ATTACH_GRAPHICS,
@@ -102,14 +104,12 @@ void DialogAttachments::UpdateList() {
 	listView->InsertColumn(2, _("Group"), wxLIST_FORMAT_LEFT, 100);
 
 	// Fill list
-	for (auto& line : ass->Line) {
-		if (AssAttachment *attach = dynamic_cast<AssAttachment*>(&line)) {
-			int row = listView->GetItemCount();
-			listView->InsertItem(row,attach->GetFileName(true));
-			listView->SetItem(row,1,PrettySize(attach->GetSize()));
-			listView->SetItem(row,2,attach->group);
-			listView->SetItemPtrData(row,wxPtrToUInt(attach));
-		}
+	for (auto attach : ass->Line | agi::of_type<AssAttachment>()) {
+		int row = listView->GetItemCount();
+		listView->InsertItem(row,attach->GetFileName(true));
+		listView->SetItem(row,1,PrettySize(attach->GetSize()));
+		listView->SetItem(row,2,attach->group);
+		listView->SetItemPtrData(row,wxPtrToUInt(attach));
 	}
 }
 

aegisub/src/dialog_resample.cpp

@@ -42,6 +42,8 @@
 #include "libresrc/libresrc.h"
 #include "video_context.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 enum {
 	LEFT = 0,
 	RIGHT = 1,
@@ -206,10 +208,8 @@ namespace {
 			diag->ParseAssTags();
 			diag->ProcessParameters(resample_tags, state);
 
-			for (auto block : diag->Blocks) {
-				if (AssDialogueBlockDrawing *drawing = dynamic_cast<AssDialogueBlockDrawing*>(block))
-					drawing->TransformCoords(state->margin[LEFT], state->margin[TOP], state->rx, state->ry);
-			}
+			for (auto drawing : diag->Blocks | agi::of_type<AssDialogueBlockDrawing>())
+				drawing->TransformCoords(state->margin[LEFT], state->margin[TOP], state->rx, state->ry);
 
 			for (size_t i = 0; i < 3; ++i)
 				diag->Margin[i] = int((diag->Margin[i] + state->margin[i]) * (i < 2 ? state->rx : state->ry) + 0.5);

aegisub/src/dialog_search_replace.cpp

@@ -54,6 +54,8 @@
 #include "subs_grid.h"
 #include "video_context.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 enum {
 	BUTTON_FIND_NEXT,
 	BUTTON_REPLACE_NEXT,
@@ -378,11 +380,7 @@ void SearchReplaceEngine::ReplaceAll() {
 	bool hasSelection = !sel.empty();
 	bool inSel = affect == 1;
 
-	// Scan
-	for (auto& line : context->ass->Line) {
-		AssDialogue *diag = dynamic_cast<AssDialogue*>(&line);
-		if (!diag) continue;
-
+	for (auto diag : context->ass->Line | agi::of_type<AssDialogue>()) {
 		// Check if row is selected
 		if (inSel && hasSelection && !sel.count(diag))
 			continue;

aegisub/src/dialog_selection.cpp

@@ -45,6 +45,8 @@
 #include "main.h"
 #include "selection_controller.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 enum {
 	ACTION_SET = 0,
 	ACTION_ADD,
@@ -113,9 +115,7 @@ static std::set<AssDialogue*> process(wxString match_text, bool match_case, int
 	std::function<bool (wxString)> pred = get_predicate(mode, &re, match_case, match_text);
 
 	std::set<AssDialogue*> matches;
-	for (auto& line : ass->Line) {
-		AssDialogue *diag = dynamic_cast<AssDialogue*>(&line);
-		if (!diag) continue;
+	for (auto diag : ass->Line | agi::of_type<AssDialogue>()) {
 		if (diag->Comment && !comments) continue;
 		if (!diag->Comment && !dialogue) continue;
 

aegisub/src/dialog_shift_times.cpp

@@ -38,6 +38,7 @@
 
 #include <libaegisub/io.h>
 #include <libaegisub/log.h>
+#include <libaegisub/of_type_adaptor.h>
 
 #include <libaegisub/cajun/elements.h>
 #include <libaegisub/cajun/reader.h>
@@ -352,9 +353,7 @@ void DialogShiftTimes::Process(wxCommandEvent &) {
 	int block_start = 0;
 	json::Array shifted_blocks;
 
-	for (auto& entry : context->ass->Line) {
-		AssDialogue *line = dynamic_cast<AssDialogue*>(&entry);
-		if (!line) continue;
+	for (auto line : context->ass->Line | agi::of_type<AssDialogue>()) {
 		++row_number;
 
 		if (!sel.count(line)) {

aegisub/src/dialog_style_editor.cpp

@@ -63,6 +63,8 @@
 #include "utils.h"
 #include "validators.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 /// Style rename helper that walks a file searching for a style and optionally
 /// updating references to it
 class StyleRenamer {
@@ -87,10 +89,7 @@ class StyleRenamer {
 		found_any = false;
 		do_replace = replace;
 
-		for (auto& line : c->ass->Line) {
-			AssDialogue *diag = dynamic_cast<AssDialogue*>(&line);
-			if (!diag) continue;
-
+		for (auto diag : c->ass->Line | agi::of_type<AssDialogue>()) {
 			if (diag->Style == source_name) {
 				if (replace)
 					diag->Style = new_name;

aegisub/src/dialog_style_manager.cpp

@@ -67,6 +67,8 @@
 #include "subtitle_format.h"
 #include "utils.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 using std::placeholders::_1;
 
 namespace {
@@ -274,11 +276,9 @@ void DialogStyleManager::LoadCurrentStyles(int commit_type) {
 		CurrentList->Clear();
 		styleMap.clear();
 
-		for (auto& line : c->ass->Line) {
-			if (AssStyle *style = dynamic_cast<AssStyle*>(&line)) {
-				CurrentList->Append(style->name);
-				styleMap.push_back(style);
-			}
+		for (auto style : c->ass->Line | agi::of_type<AssStyle>()) {
+			CurrentList->Append(style->name);
+			styleMap.push_back(style);
 		}
 	}
 

aegisub/src/export_fixstyle.cpp

@@ -34,15 +34,18 @@
 
 #include "config.h"
 
+#include "export_fixstyle.h"
+
 #ifndef AGI_PRE
 #include <algorithm>
 #include <functional>
 #endif
 
-#include "export_fixstyle.h"
 #include "ass_file.h"
 #include "ass_dialogue.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 AssFixStylesFilter::AssFixStylesFilter()
 : AssExportFilter(_("Fix Styles"), _("Fixes styles by replacing any style that isn't available on file with Default."), -5000, true)
 {
@@ -53,10 +56,8 @@ void AssFixStylesFilter::ProcessSubs(AssFile *subs, wxWindow *) {
 	for_each(styles.begin(), styles.end(), std::mem_fun_ref(&wxString::MakeLower));
 	styles.Sort();
 
-	for (auto& line : subs->Line) {
-		if (AssDialogue *diag = dynamic_cast<AssDialogue*>(&line)) {
-			if (!std::binary_search(styles.begin(), styles.end(), diag->Style.Lower()))
-				diag->Style = "Default";
-		}
+	for (auto diag : subs->Line | agi::of_type<AssDialogue>()) {
+		if (!std::binary_search(styles.begin(), styles.end(), diag->Style.Lower()))
+			diag->Style = "Default";
 	}
 }

aegisub/src/export_framerate.cpp

@@ -54,6 +54,8 @@
 #include "utils.h"
 #include "video_context.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 AssTransformFramerateFilter::AssTransformFramerateFilter()
 : AssExportFilter(_("Transform Framerate"), _("Transform subtitle times, including those in override tags, from an input framerate to an output framerate.\n\nThis is useful for converting regular time subtitles to VFRaC time subtitles for hardsubbing.\nIt can also be used to convert subtitles to a different speed video, such as NTSC to PAL speedup."), 1000)
 , c(0)
@@ -208,10 +210,7 @@ void AssTransformFramerateFilter::TransformTimeTags(wxString name,int n,AssOverr
 
 void AssTransformFramerateFilter::TransformFrameRate(AssFile *subs) {
 	if (!Input->IsLoaded() || !Output->IsLoaded()) return;
-	for (auto& entry : subs->Line) {
-		AssDialogue *curDialogue = dynamic_cast<AssDialogue*>(&entry);
-		if (!curDialogue) continue;
-
+	for (auto curDialogue : subs->Line | agi::of_type<AssDialogue>()) {
 		line = curDialogue;
 		newK = 0;
 		oldK = 0;

aegisub/src/subs_edit_box.cpp

@@ -68,6 +68,8 @@
 #include "validators.h"
 #include "video_context.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 namespace {
 template<class T>
 struct field_setter : public std::binary_function<AssDialogue*, T, void> {
@@ -315,10 +317,8 @@ void SubsEditBox::PopulateList(wxComboBox *combo, wxString AssDialogue::*field)
 	wxEventBlocker blocker(this);
 
 	std::set<wxString> values;
-	for (auto& line : c->ass->Line) {
-		if (AssDialogue *diag = dynamic_cast<AssDialogue*>(&line))
-			values.insert(diag->*field);
-	}
+	for (auto diag : c->ass->Line | agi::of_type<AssDialogue>())
+		values.insert(diag->*field);
 	values.erase("");
 	wxArrayString arrstr;
 	arrstr.reserve(values.size());

aegisub/src/subtitle_format.cpp

@@ -57,6 +57,8 @@
 #include "utils.h"
 #include "video_context.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 using namespace std::placeholders;
 
 SubtitleFormat::SubtitleFormat(wxString const& name)
@@ -164,22 +166,17 @@ agi::vfr::Framerate SubtitleFormat::AskForFPS(bool allow_vfr, bool show_smpte) {
 }
 
 void SubtitleFormat::StripTags(AssFile &file) {
-	for (auto &line : file.Line) {
-		if (AssDialogue *current = dynamic_cast<AssDialogue*>(&line)) {
-			current->StripTags();
-		}
-	}
+	for (auto current : file.Line | agi::of_type<AssDialogue>())
+		current->StripTags();
 }
 
 void SubtitleFormat::ConvertNewlines(AssFile &file, wxString const& newline, bool mergeLineBreaks) {
-	for (auto &line : file.Line) {
-		if (AssDialogue *current = dynamic_cast<AssDialogue*>(&line)) {
-			current->Text.Replace("\\h", " ");
-			current->Text.Replace("\\n", newline);
-			current->Text.Replace("\\N", newline);
-			if (mergeLineBreaks) {
-				while (current->Text.Replace(newline+newline, newline));
-			}
+	for (auto current : file.Line | agi::of_type<AssDialogue>()) {
+		current->Text.Replace("\\h", " ");
+		current->Text.Replace("\\n", newline);
+		current->Text.Replace("\\N", newline);
+		if (mergeLineBreaks) {
+			while (current->Text.Replace(newline+newline, newline));
 		}
 	}
 }

aegisub/src/subtitle_format_ebu3264.cpp

@@ -33,6 +33,7 @@
 #include <libaegisub/exception.h>
 #include <libaegisub/io.h>
 #include <libaegisub/line_wrap.h>
+#include <libaegisub/of_type_adaptor.h>
 #include <libaegisub/scoped_ptr.h>
 
 #include "aegisub_endian.h"
@@ -384,11 +385,8 @@ namespace
 		subs_list.reserve(copy.Line.size());
 
 		// convert to intermediate format
-		for (auto& orgline : copy.Line)
+		for (auto line : copy.Line | agi::of_type<AssDialogue>())
 		{
-			AssDialogue *line = dynamic_cast<AssDialogue*>(&orgline);
-			if (!line) continue;
-
 			// add a new subtitle and work on it
 			subs_list.push_back(EbuSubtitle());
 			EbuSubtitle &imline = subs_list.back();

aegisub/src/subtitle_format_encore.cpp

@@ -40,6 +40,8 @@
 #include "ass_file.h"
 #include "text_file_writer.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 EncoreSubtitleFormat::EncoreSubtitleFormat()
 : SubtitleFormat("Adobe Encore")
 {
@@ -77,10 +79,8 @@ void EncoreSubtitleFormat::WriteFile(const AssFile *src, wxString const& filenam
 	// Write lines
 	int i = 0;
 	TextFileWriter file(filename, "UTF-8");
-	for (auto const& line : copy.Line) {
-		if (const AssDialogue *current = dynamic_cast<const AssDialogue*>(&line)) {
-			++i;
-			file.WriteLineToFile(wxString::Format("%i %s %s %s", i, ft.ToSMPTE(current->Start), ft.ToSMPTE(current->End), current->Text));
-		}
+	for (auto current : copy.Line | agi::of_type<AssDialogue>()) {
+		++i;
+		file.WriteLineToFile(wxString::Format("%i %s %s %s", i, ft.ToSMPTE(current->Start), ft.ToSMPTE(current->End), current->Text));
 	}
 }

aegisub/src/subtitle_format_microdvd.cpp

@@ -47,6 +47,8 @@
 #include "text_file_writer.h"
 #include "video_context.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 MicroDVDSubtitleFormat::MicroDVDSubtitleFormat()
 : SubtitleFormat("MicroDVD")
 {
@@ -142,12 +144,10 @@ void MicroDVDSubtitleFormat::WriteFile(const AssFile *src, wxString const& filen
 	}
 
 	// Write lines
-	for (auto const& line : copy.Line) {
-		if (const AssDialogue *current = dynamic_cast<const AssDialogue*>(&line)) {
-			int start = fps.FrameAtTime(current->Start, agi::vfr::START);
-			int end = fps.FrameAtTime(current->End, agi::vfr::END);
+	for (auto current : copy.Line | agi::of_type<AssDialogue>()) {
+		int start = fps.FrameAtTime(current->Start, agi::vfr::START);
+		int end = fps.FrameAtTime(current->End, agi::vfr::END);
 
-			file.WriteLineToFile(wxString::Format("{%i}{%i}%s", start, end, current->Text));
-		}
+		file.WriteLineToFile(wxString::Format("{%i}{%i}%s", start, end, current->Text));
 	}
 }

aegisub/src/subtitle_format_srt.cpp

@@ -51,6 +51,8 @@
 #include "text_file_reader.h"
 #include "text_file_writer.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 DEFINE_SIMPLE_EXCEPTION(SRTParseError, SubtitleFormatParseError, "subtitle_io/parse/srt")
 
 namespace {
@@ -508,14 +510,12 @@ void SRTSubtitleFormat::WriteFile(const AssFile *src, wxString const& filename,
 #endif
 
 	// Write lines
-	int i=1;
-	for (auto const& line : copy.Line) {
-		if (const AssDialogue *current = dynamic_cast<const AssDialogue*>(&line)) {
-			file.WriteLineToFile(wxString::Format("%d", i++));
-			file.WriteLineToFile(WriteSRTTime(current->Start) + " --> " + WriteSRTTime(current->End));
-			file.WriteLineToFile(ConvertTags(current));
-			file.WriteLineToFile("");
-		}
+	int i=0;
+	for (auto current : copy.Line | agi::of_type<AssDialogue>()) {
+		file.WriteLineToFile(wxString::Format("%d", ++i));
+		file.WriteLineToFile(WriteSRTTime(current->Start) + " --> " + WriteSRTTime(current->End));
+		file.WriteLineToFile(ConvertTags(current));
+		file.WriteLineToFile("");
 	}
 }
 
@@ -536,10 +536,7 @@ bool SRTSubtitleFormat::CanSave(const AssFile *file) const {
 		// Check dialogue
 		if (const AssDialogue *curdiag = dynamic_cast<const AssDialogue*>(&line)) {
 			std::vector<AssDialogueBlock*> blocks = curdiag->ParseTags();
-			for (auto block : blocks) {
-				AssDialogueBlockOverride *ovr = dynamic_cast<AssDialogueBlockOverride*>(block);
-				if (!ovr) continue;
-
+			for (auto ovr : blocks | agi::of_type<AssDialogueBlockOverride>()) {
 				// Verify that all overrides used are supported
 				for (auto tag : ovr->Tags) {
 					if (!std::binary_search(supported_tags, std::end(supported_tags), tag->Name)) {

aegisub/src/subtitle_format_transtation.cpp

@@ -46,6 +46,8 @@
 #include "ass_time.h"
 #include "text_file_writer.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 TranStationSubtitleFormat::TranStationSubtitleFormat()
 : SubtitleFormat("TranStation")
 {
@@ -75,16 +77,13 @@ void TranStationSubtitleFormat::WriteFile(const AssFile *src, wxString const& fi
 	SmpteFormatter ft(fps);
 	TextFileWriter file(filename, encoding);
 	AssDialogue *prev = 0;
-	for (auto& line : copy.Line) {
-		AssDialogue *cur = dynamic_cast<AssDialogue*>(&line);
-
-		if (prev && cur) {
+	for (auto cur : copy.Line | agi::of_type<AssDialogue>()) {
+		if (prev) {
 			file.WriteLineToFile(ConvertLine(&copy, prev, fps, ft, cur->Start));
 			file.WriteLineToFile("");
 		}
 
-		if (cur)
-			prev = cur;
+		prev = cur;
 	}
 
 	// flush last line

aegisub/src/subtitle_format_ttxt.cpp

@@ -46,6 +46,9 @@
 #include "compat.h"
 #include "main.h"
 
+#include <libaegisub/of_type_adaptor.h>
+#include <boost/range/adaptor/reversed.hpp>
+
 DEFINE_SIMPLE_EXCEPTION(TTXTParseError, SubtitleFormatParseError, "subtitle_io/parse/ttxt")
 
 TTXTSubtitleFormat::TTXTSubtitleFormat()
@@ -176,14 +179,9 @@ void TTXTSubtitleFormat::WriteFile(const AssFile *src, wxString const& filename,
 
 	// Create lines
 	const AssDialogue *prev = 0;
-	for (auto const& line : copy.Line) {
-		const AssDialogue *current = dynamic_cast<const AssDialogue*>(&line);
-		if (current && !current->Comment) {
-			WriteLine(root, prev, current);
-			prev = current;
-		}
-		else
-			throw TTXTParseError("Unexpected line type in TTXT file", 0);
+	for (auto current : copy.Line | agi::of_type<AssDialogue>()) {
+		WriteLine(root, prev, current);
+		prev = current;
 	}
 
 	// Save XML
@@ -268,11 +266,9 @@ void TTXTSubtitleFormat::ConvertToTTXT(AssFile &file) const {
 
 	// Find last line
 	AssTime lastTime;
-	for (EntryList::reverse_iterator cur = file.Line.rbegin(); cur != file.Line.rend(); ++cur) {
-		if (AssDialogue *prev = dynamic_cast<AssDialogue*>(&*cur)) {
-			lastTime = prev->End;
-			break;
-		}
+	for (auto line : file.Line | boost::adaptors::reversed | agi::of_type<AssDialogue>()) {
+		lastTime = line->End;
+		break;
 	}
 
 	// Insert blank line at the end

aegisub/src/subtitle_format_txt.cpp

@@ -46,6 +46,8 @@
 #include "utils.h"
 #include "version.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 TXTSubtitleFormat::TXTSubtitleFormat()
 : SubtitleFormat("Plain-Text")
 {
@@ -129,9 +131,8 @@ void TXTSubtitleFormat::WriteFile(const AssFile *src, wxString const& filename,
 	size_t num_actor_names = 0, num_dialogue_lines = 0;
 
 	// Detect number of lines with Actor field filled out
-	for (auto const& line : src->Line) {
-		const AssDialogue *dia = dynamic_cast<const AssDialogue*>(&line);
-		if (dia && !dia->Comment) {
+	for (auto dia : src->Line | agi::of_type<AssDialogue>()) {
+		if (!dia->Comment) {
 			num_dialogue_lines++;
 			if (!dia->Actor.empty())
 				num_actor_names++;
@@ -146,10 +147,7 @@ void TXTSubtitleFormat::WriteFile(const AssFile *src, wxString const& filename,
 	file.WriteLineToFile(wxString("# Exported by Aegisub ") + GetAegisubShortVersionString());
 
 	// Write the file
-	for (auto const& line : src->Line) {
-		const AssDialogue *dia = dynamic_cast<const AssDialogue*>(&line);
-		if (!dia) continue;
-
+	for (auto dia : src->Line | agi::of_type<AssDialogue>()) {
 		wxString out_line;
 
 		if (dia->Comment)
@@ -161,10 +159,8 @@ void TXTSubtitleFormat::WriteFile(const AssFile *src, wxString const& filename,
 		wxString out_text;
 		if (strip_formatting) {
 			std::vector<AssDialogueBlock*> blocks = dia->ParseTags();
-			for (auto block : blocks) {
-				if (block->GetType() == BLOCK_PLAIN)
-					out_text += block->GetText();
-			}
+			for (auto block : blocks | agi::of_type<AssDialogueBlockPlain>())
+				out_text += block->GetText();
 			delete_clear(blocks);
 		}
 		else {

aegisub/src/visual_tool.cpp

@@ -42,10 +42,7 @@
 #include "visual_tool_drag.h"
 #include "visual_tool_vector_clip.h"
 
-template<class C, class F>
-static void for_each(C &range, F func) {
-	std::for_each(range.begin(), range.end(), func);
-}
+#include <libaegisub/of_type_adaptor.h>
 
 using std::placeholders::_1;
 
@@ -218,9 +215,10 @@ void VisualTool<FeatureType>::OnMouseEvent(wxMouseEvent &event) {
 	if (dragging) {
 		// continue drag
 		if (event.LeftIsDown()) {
-			for_each(sel_features, std::bind(&FeatureType::UpdateDrag, _1,
-				mouse_pos - drag_start, shift_down));
-			for_each(sel_features, std::bind(&VisualTool<FeatureType>::UpdateDrag, this, _1));
+			for (auto sel : sel_features)
+				sel->UpdateDrag(mouse_pos - drag_start, shift_down);
+			for (auto sel : sel_features)
+				UpdateDrag(sel);
 			Commit();
 			need_render = true;
 		}
@@ -273,7 +271,7 @@ void VisualTool<FeatureType>::OnMouseEvent(wxMouseEvent &event) {
 				c->selectionController->SetActiveLine(active_feature->line);
 
 			if (InitializeDrag(active_feature)) {
-				for_each(sel_features, std::bind(&VisualDraggableFeature::StartDrag, _1));
+				for (auto sel : sel_features) sel->StartDrag();
 				dragging = true;
 				parent->CaptureMouse();
 			}
@@ -370,10 +368,7 @@ struct scoped_tag_parse {
 
 // Find a tag's parameters in a line or return NULL if it's not found
 static param_vec find_tag(const AssDialogue *line, wxString tag_name) {
-	for (auto block : line->Blocks) {
-		const AssDialogueBlockOverride *ovr = dynamic_cast<const AssDialogueBlockOverride*>(block);
-		if (!ovr) continue;
-
+	for (auto ovr : line->Blocks | agi::of_type<AssDialogueBlockOverride>()) {
 		for (auto tag : ovr->Tags) {
 			if (tag->Name == tag_name)
 				return &tag->Params;
@@ -552,8 +547,8 @@ wxString VisualToolBase::GetLineVectorClip(AssDialogue *diag, int &scale, bool &
 }
 
 void VisualToolBase::SetSelectedOverride(wxString const& tag, wxString const& value) {
-	for_each(c->selectionController->GetSelectedSet(),
-		std::bind(&VisualToolBase::SetOverride, this, _1, tag, value));
+	for (auto line : c->selectionController->GetSelectedSet())
+		SetOverride(line, tag, value);
 }
 
 void VisualToolBase::SetOverride(AssDialogue* line, wxString const& tag, wxString const& value) {

aegisub/src/visual_tool_drag.cpp

@@ -39,6 +39,8 @@
 #include "video_context.h"
 #include "video_display.h"
 
+#include <libaegisub/of_type_adaptor.h>
+
 static const DraggableFeatureType DRAG_ORIGIN = DRAG_BIG_TRIANGLE;
 static const DraggableFeatureType DRAG_START = DRAG_BIG_SQUARE;
 static const DraggableFeatureType DRAG_END = DRAG_BIG_CIRCLE;
@@ -114,9 +116,8 @@ void VisualToolDrag::OnFileChanged() {
 	primary = 0;
 	active_feature = features.end();
 
-	for (auto& line : c->ass->Line) {
-		AssDialogue *diag = dynamic_cast<AssDialogue*>(&line);
-		if (diag && IsDisplayed(diag))
+	for (auto diag : c->ass->Line | agi::of_type<AssDialogue>()) {
+		if (IsDisplayed(diag))
 			MakeFeatures(diag);
 	}
 
@@ -130,10 +131,7 @@ void VisualToolDrag::OnFrameChanged() {
 	feature_iterator feat = features.begin();
 	feature_iterator end = features.end();
 
-	for (auto& line : c->ass->Line) {
-		AssDialogue *diag = dynamic_cast<AssDialogue*>(&line);
-		if (!diag) continue;
-
+	for (auto diag : c->ass->Line | agi::of_type<AssDialogue>()) {
 		if (IsDisplayed(diag)) {
 			// Features don't exist and should
 			if (feat == end || feat->line != diag)