diff --git a/Subsurface-mobile.pro b/Subsurface-mobile.pro
index f1afbceaf..36db76407 100644
--- a/Subsurface-mobile.pro
+++ b/Subsurface-mobile.pro
@@ -206,6 +206,7 @@ HEADERS += \
 	core/pref.h \
 	core/profile.h \
 	core/qthelper.h \
+	core/range.h \
 	core/save-html.h \
 	core/statistics.h \
 	core/units.h \
diff --git a/core/CMakeLists.txt b/core/CMakeLists.txt
index 54cafd7d6..83ad52eb9 100644
--- a/core/CMakeLists.txt
+++ b/core/CMakeLists.txt
@@ -147,6 +147,7 @@ set(SUBSURFACE_CORE_LIB_SRCS
 	qt-init.cpp
 	qthelper.cpp
 	qthelper.h
+	range.h
 	sample.c
 	sample.h
 	save-git.c
diff --git a/core/filterconstraint.cpp b/core/filterconstraint.cpp
index 75bfaed0a..e5d5e4a60 100644
--- a/core/filterconstraint.cpp
+++ b/core/filterconstraint.cpp
@@ -104,26 +104,11 @@ static const char *negate_description[2] {
 	QT_TRANSLATE_NOOP("gettextFromC", "is not"),
 };
 
-static constexpr size_t type_descriptions_count()
-{
-	return std::size(type_descriptions);
-}
-
-static constexpr size_t string_mode_descriptions_count()
-{
-	return std::size(string_mode_descriptions);
-}
-
-static constexpr size_t range_mode_descriptions_count()
-{
-	return std::size(range_mode_descriptions);
-}
-
 static const type_description *get_type_description(enum filter_constraint_type type)
 {
-	for (size_t i = 0; i < type_descriptions_count(); ++i) {
-		if (type_descriptions[i].type == type)
-			return &type_descriptions[i];
+	for (const auto &desc: type_descriptions) {
+		if (desc.type == type)
+			return &desc;
 	}
 	report_error("unknown filter constraint type: %d", type);
 	return nullptr;
@@ -131,9 +116,9 @@ static const type_description *get_type_description(enum filter_constraint_type
 
 static const string_mode_description *get_string_mode_description(enum filter_constraint_string_mode mode)
 {
-	for (size_t i = 0; i < string_mode_descriptions_count(); ++i) {
-		if (string_mode_descriptions[i].mode == mode)
-			return &string_mode_descriptions[i];
+	for (const auto &desc: string_mode_descriptions) {
+		if (desc.mode == mode)
+			return &desc;
 	}
 	report_error("unknown filter constraint string mode: %d", mode);
 	return nullptr;
@@ -141,9 +126,9 @@ static const string_mode_description *get_string_mode_description(enum filter_co
 
 static const range_mode_description *get_range_mode_description(enum filter_constraint_range_mode mode)
 {
-	for (size_t i = 0; i < range_mode_descriptions_count(); ++i) {
-		if (range_mode_descriptions[i].mode == mode)
-			return &range_mode_descriptions[i];
+	for (const auto &desc: range_mode_descriptions) {
+		if (desc.mode == mode)
+			return &desc;
 	}
 	report_error("unknown filter constraint range mode: %d", mode);
 	return nullptr;
@@ -151,9 +136,9 @@ static const range_mode_description *get_range_mode_description(enum filter_cons
 
 static enum filter_constraint_type filter_constraint_type_from_string(const char *s)
 {
-	for (size_t i = 0; i < type_descriptions_count(); ++i) {
-		if (same_string(type_descriptions[i].token, s))
-			return type_descriptions[i].type;
+	for (const auto &desc: type_descriptions) {
+		if (same_string(desc.token, s))
+			return desc.type;
 	}
 	report_error("unknown filter constraint type: %s", s);
 	return FILTER_CONSTRAINT_DATE;
@@ -161,9 +146,9 @@ static enum filter_constraint_type filter_constraint_type_from_string(const char
 
 static enum filter_constraint_string_mode filter_constraint_string_mode_from_string(const char *s)
 {
-	for (size_t i = 0; i < string_mode_descriptions_count(); ++i) {
-		if (same_string(string_mode_descriptions[i].token, s))
-			return string_mode_descriptions[i].mode;
+	for (const auto &desc: string_mode_descriptions) {
+		if (same_string(desc.token, s))
+			return desc.mode;
 	}
 	report_error("unknown filter constraint string mode: %s", s);
 	return FILTER_CONSTRAINT_EXACT;
@@ -171,9 +156,9 @@ static enum filter_constraint_string_mode filter_constraint_string_mode_from_str
 
 static enum filter_constraint_range_mode filter_constraint_range_mode_from_string(const char *s)
 {
-	for (size_t i = 0; i < range_mode_descriptions_count(); ++i) {
-		if (same_string(range_mode_descriptions[i].token, s))
-			return range_mode_descriptions[i].mode;
+	for (const auto &desc: range_mode_descriptions) {
+		if (same_string(desc.token, s))
+			return desc.mode;
 	}
 	report_error("unknown filter constraint range mode: %s", s);
 	return FILTER_CONSTRAINT_EQUAL;
@@ -217,21 +202,21 @@ extern "C" int filter_constraint_range_mode_to_index(enum filter_constraint_rang
 
 extern "C" enum filter_constraint_type filter_constraint_type_from_index(int index)
 {
-	if (index >= 0 && index < (int)type_descriptions_count())
+	if (index >= 0 && index < (int)std::size(type_descriptions))
 		return type_descriptions[index].type;
 	return (enum filter_constraint_type)-1;
 }
 
 extern "C" enum filter_constraint_string_mode filter_constraint_string_mode_from_index(int index)
 {
-	if (index >= 0 && index < (int)string_mode_descriptions_count())
+	if (index >= 0 && index < (int)std::size(string_mode_descriptions))
 		return string_mode_descriptions[index].mode;
 	return (enum filter_constraint_string_mode)-1;
 }
 
 extern "C" enum filter_constraint_range_mode filter_constraint_range_mode_from_index(int index)
 {
-	if (index >= 0 && index < (int)range_mode_descriptions_count())
+	if (index >= 0 && index < (int)std::size(range_mode_descriptions))
 		return range_mode_descriptions[index].mode;
 	return (enum filter_constraint_range_mode)-1;
 }
@@ -347,32 +332,32 @@ static double base_to_display_unit(int i, enum filter_constraint_type type)
 QStringList filter_constraint_type_list_translated()
 {
 	QStringList res;
-	for (size_t i = 0; i < type_descriptions_count(); ++i)
-		res.push_back(gettextFromC::tr(type_descriptions[i].text_ui));
+	for (const auto &desc: type_descriptions)
+		res.push_back(gettextFromC::tr(desc.text_ui));
 	return res;
 }
 
 QStringList filter_constraint_string_mode_list_translated()
 {
 	QStringList res;
-	for (size_t i = 0; i < string_mode_descriptions_count(); ++i)
-		res.push_back(gettextFromC::tr(string_mode_descriptions[i].text_ui));
+	for (const auto &desc: string_mode_descriptions)
+		res.push_back(gettextFromC::tr(desc.text_ui));
 	return res;
 }
 
 QStringList filter_constraint_range_mode_list_translated()
 {
 	QStringList res;
-	for (size_t i = 0; i < range_mode_descriptions_count(); ++i)
-		res.push_back(gettextFromC::tr(range_mode_descriptions[i].text_ui));
+	for (const auto &desc: range_mode_descriptions)
+		res.push_back(gettextFromC::tr(desc.text_ui));
 	return res;
 }
 
 QStringList filter_constraint_range_mode_list_translated_date()
 {
 	QStringList res;
-	for (size_t i = 0; i < range_mode_descriptions_count(); ++i)
-		res.push_back(gettextFromC::tr(range_mode_descriptions[i].text_ui_date));
+	for (const auto &desc: range_mode_descriptions)
+		res.push_back(gettextFromC::tr(desc.text_ui_date));
 	return res;
 }
 
diff --git a/core/planner.c b/core/planner.c
index 598e568bf..a4c93ba77 100644
--- a/core/planner.c
+++ b/core/planner.c
@@ -92,7 +92,7 @@ int get_cylinderid_at_time(struct dive *dive, struct divecomputer *dc, duration_
 	return cylinder_idx;
 }
 
-int get_gasidx(struct dive *dive, struct gasmix mix)
+static int get_gasidx(struct dive *dive, struct gasmix mix)
 {
 	return find_best_gasmix_match(mix, &dive->cylinders);
 }
diff --git a/core/planner.h b/core/planner.h
index 6d0353db0..48d2bb33f 100644
--- a/core/planner.h
+++ b/core/planner.h
@@ -42,22 +42,13 @@ extern "C" {
 
 extern int validate_gas(const char *text, struct gasmix *gas);
 extern int validate_po2(const char *text, int *mbar_po2);
-extern timestamp_t current_time_notz(void);
-extern void set_last_stop(bool last_stop_6m);
-extern void set_verbatim(bool verbatim);
-extern void set_display_runtime(bool display);
-extern void set_display_duration(bool display);
-extern void set_display_transitions(bool display);
 extern int get_cylinderid_at_time(struct dive *dive, struct divecomputer *dc, duration_t time);
-extern int get_gasidx(struct dive *dive, struct gasmix mix);
 extern bool diveplan_empty(struct diveplan *diveplan);
 extern void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool show_disclaimer, int error);
 extern const char *get_planner_disclaimer();
 extern char *get_planner_disclaimer_formatted();
 
 extern void free_dps(struct diveplan *diveplan);
-extern struct dive *planned_dive;
-extern char *cache_data;
 
 struct divedatapoint *plan_add_segment(struct diveplan *diveplan, int duration, int depth, int cylinderid, int po2, bool entered, enum divemode_t divemode);
 struct divedatapoint *create_dp(int time_incr, int depth, int cylinderid, int po2);
diff --git a/core/qthelper.cpp b/core/qthelper.cpp
index 1682db44b..62f3f5755 100644
--- a/core/qthelper.cpp
+++ b/core/qthelper.cpp
@@ -36,7 +36,6 @@
 #include <QApplication>
 #include <QTextDocument>
 #include <QPainter>
-#include <QProgressDialog>	// TODO: remove with convertThumbnails()
 #include <QSvgRenderer>
 #include <cstdarg>
 #include <cstdint>
@@ -676,7 +675,7 @@ QString get_water_type_string(int salinity)
 QStringList getWaterTypesAsString()
 {
 	QStringList res;
-	res.reserve(std::end(waterTypes) - std::begin(waterTypes)); // Waiting for C++17's std::size()
+	res.reserve(std::size(waterTypes));
 	for (const char *t: waterTypes)
 		res.push_back(gettextFromC::tr(t));
 	return res;
@@ -719,17 +718,17 @@ static const char *printing_templates = "printing_templates";
 
 QString getPrintingTemplatePathUser()
 {
-	static QString path = QString();
-	if (path.isEmpty())
-		path = QString(system_default_directory()) + QDir::separator() + QString(printing_templates);
+	// Function-local statics are initialized on first invocation
+	static QString path(QString(system_default_directory()) +
+			    QDir::separator() +
+			    QString(printing_templates));
 	return path;
 }
 
 QString getPrintingTemplatePathBundle()
 {
-	static QString path = QString();
-	if (path.isEmpty())
-		path = getSubsurfaceDataPath(printing_templates);
+	// Function-local statics are initialized on first invocation
+	static QString path(getSubsurfaceDataPath(printing_templates));
 	return path;
 }
 
@@ -1072,45 +1071,6 @@ extern "C" char *hashfile_name_string()
 	return copy_qstring(hashfile_name());
 }
 
-// During a transition period, convert old thumbnail-hashes to individual files
-// TODO: remove this code in due course
-static void convertThumbnails(const QHash <QString, QImage> &thumbnails)
-{
-	if (thumbnails.empty())
-		return;
-	// This is a singular occurrence, therefore translating the strings seems not worth it
-	QProgressDialog progress("Convert thumbnails...", "Abort", 0, thumbnails.size());
-	progress.setWindowModality(Qt::WindowModal);
-
-	int count = 0;
-	for (const QString &name: thumbnails.keys()) {
-		const QImage thumbnail = thumbnails[name];
-
-		if (thumbnail.isNull())
-			continue;
-
-		// This is duplicate code (see qt-models/divepicturemodel.cpp)
-		// Not a problem, since this routine will be removed in due course.
-		QString filename = thumbnailFileName(name);
-		if (filename.isEmpty())
-			continue;
-
-		QSaveFile file(filename);
-		if (!file.open(QIODevice::WriteOnly))
-			return;
-		QDataStream stream(&file);
-
-		quint32 type = MEDIATYPE_PICTURE;
-		stream << type;
-		stream << thumbnail;
-		file.commit();
-
-		progress.setValue(++count);
-		if (progress.wasCanceled())
-			break;
-	}
-}
-
 // TODO: This is a temporary helper struct. Remove in due course with convertLocalFilename().
 struct HashToFile {
 	QByteArray hash;
@@ -1129,7 +1089,7 @@ static void convertLocalFilename(const QHash<QString, QByteArray> &hashOf, const
 		return;
 
 	// Create a vector of hash/filename pairs and sort by hash.
-	// Elements can than be accessed with binary search.
+	// Elements can then be accessed with binary search.
 	QHash<QByteArray, QString> canonicalFilenameByHash;
 	QVector<HashToFile> h2f;
 	h2f.reserve(hashOf.size());
@@ -1166,7 +1126,6 @@ void read_hashes()
 		stream >> localFilenameOf;
 		locker.unlock();
 		hashfile.close();
-		convertThumbnails(thumbnailCache);
 		convertLocalFilename(hashOf, localFilenameByHash);
 	}
 	QMutexLocker locker(&hashOfMutex);
diff --git a/core/qthelper.h b/core/qthelper.h
index ddc0d3ac3..af73cc813 100644
--- a/core/qthelper.h
+++ b/core/qthelper.h
@@ -108,31 +108,6 @@ void uiNotification(const QString &msg);
 #define TITLE_OR_TEXT(_t, _m) _t, _m
 #endif
 
-// Move a range in a vector to a different position.
-// The parameters are given according to the usual STL-semantics:
-//	v: a container with STL-like random access iterator via std::begin(...)
-//	rangeBegin: index of first element
-//	rangeEnd: index one *past* last element
-//	destination: index to element before which the range will be moved
-// Owing to std::begin() magic, this function works with STL-like containers:
-//	QVector<int> v{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
-//	moveInVector(v, 1, 4, 6);
-// as well as with C-style arrays:
-//	int array[10] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
-//	moveInVector(array, 1, 4, 6);
-// Both calls will have the following effect:
-//	Before: 0 1 2 3 4 5 6 7 8 9
-//	After:  0 4 5 1 2 3 6 7 8 9
-// No sanitizing of the input arguments is performed.
-template <typename Vector>
-void moveInVector(Vector &v, int rangeBegin, int rangeEnd, int destination)
-{
-	auto it = std::begin(v);
-	if (destination > rangeEnd)
-		std::rotate(it + rangeBegin, it + rangeEnd, it + destination);
-	else if (destination < rangeBegin)
-		std::rotate(it + destination, it + rangeBegin, it + rangeEnd);
-}
 #endif
 
 // 3) Functions visible to C and C++
diff --git a/core/range.h b/core/range.h
new file mode 100644
index 000000000..561424079
--- /dev/null
+++ b/core/range.h
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+// Helper functions for range manipulations
+#ifndef RANGE_H
+#define RANGE_H
+
+#include <utility>	// for std::pair
+#include <vector>	// we need a declaration of std::begin() and std::end()
+
+// Move a range in a vector to a different position.
+// The parameters are given according to the usual STL-semantics:
+//	v: a container with STL-like random access iterator via std::begin(...)
+//	rangeBegin: index of first element
+//	rangeEnd: index one *past* last element
+//	destination: index to element before which the range will be moved
+// Owing to std::begin() magic, this function works with STL-like containers:
+//	QVector<int> v{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
+//	move_in_range(v, 1, 4, 6);
+// as well as with C-style arrays:
+//	int array[10] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
+//	move_in_range(array, 1, 4, 6);
+// Both calls will have the following effect:
+//	Before: 0 1 2 3 4 5 6 7 8 9
+//	After:  0 4 5 1 2 3 6 7 8 9
+// No sanitizing of the input arguments is performed.
+template <typename Range>
+void move_in_range(Range &v, int rangeBegin, int rangeEnd, int destination)
+{
+	auto it = std::begin(v);
+	if (destination > rangeEnd)
+		std::rotate(it + rangeBegin, it + rangeEnd, it + destination);
+	else if (destination < rangeBegin)
+		std::rotate(it + destination, it + rangeBegin, it + rangeEnd);
+}
+
+// A rudimentary adaptor for looping over ranges with an index:
+//	for (auto [idx, item]: enumerated_range(v)) ...
+// The index is a signed integer, since this is what we use more often.
+template <typename Range>
+class enumerated_range
+{
+	Range &base;
+public:
+	using base_iterator = decltype(std::begin(std::declval<Range>()));
+	class iterator {
+		int idx;
+		base_iterator it;
+	public:
+		std::pair<int, decltype(*it)> operator*() const
+		{
+			return { idx, *it };
+		}
+		iterator &operator++()
+		{
+			++idx;
+			++it;
+			return *this;
+		}
+		iterator(int idx, base_iterator it) : idx(idx), it(it)
+		{
+		}
+		bool operator==(const iterator &it2) const
+		{
+			return it == it2.it;
+		}
+		bool operator!=(const iterator &it2) const
+		{
+			return it != it2.it;
+		}
+	};
+
+	iterator begin()
+	{
+		return iterator(0, std::begin(base));
+	}
+	iterator end()
+	{
+		return iterator(-1, std::end(base));
+	}
+
+	enumerated_range(Range &base) : base(base)
+	{
+	}
+};
+
+// Find the index of an element in a range. Return -1 if not found
+// Range must have a random access iterator.
+template <typename Range, typename Element>
+int index_of(const Range &range, const Element &e)
+{
+	auto it = std::find(std::begin(range), std::end(range), e);
+	return it == std::end(range) ? -1 : it - std::begin(range);
+}
+
+template <typename Range, typename Func>
+int index_of_if(const Range &range, Func f)
+{
+	auto it = std::find_if(std::begin(range), std::end(range), f);
+	return it == std::end(range) ? -1 : it - std::begin(range);
+}
+
+#endif
diff --git a/desktop-widgets/printoptions.cpp b/desktop-widgets/printoptions.cpp
index e36351443..88cf57c4f 100644
--- a/desktop-widgets/printoptions.cpp
+++ b/desktop-widgets/printoptions.cpp
@@ -3,6 +3,7 @@
 #include "templateedit.h"
 #include "templatelayout.h"
 #include "core/qthelper.h"
+#include "core/range.h"
 
 #include <QDebug>
 #include <QFileDialog>
@@ -63,10 +64,10 @@ void PrintOptions::setupTemplates()
 	currList.sort();
 	int current_index = 0;
 	ui.printTemplate->clear();
-	Q_FOREACH(const QString& theme, currList) {
+	for (auto [idx, theme]: enumerated_range(currList)) {
 		 // find the stored template in the list
 		if (theme == storedTemplate || theme == lastImportExportTemplate)
-			current_index = currList.indexOf(theme);
+			current_index = idx;
 		ui.printTemplate->addItem(theme.split('.')[0], theme);
 	}
 	ui.printTemplate->setCurrentIndex(current_index);
diff --git a/profile-widget/profilewidget2.cpp b/profile-widget/profilewidget2.cpp
index 0d379d797..65ccb64a7 100644
--- a/profile-widget/profilewidget2.cpp
+++ b/profile-widget/profilewidget2.cpp
@@ -5,6 +5,7 @@
 #include "core/event.h"
 #include "core/subsurface-string.h"
 #include "core/qthelper.h"
+#include "core/range.h"
 #include "core/settings/qPrefTechnicalDetails.h"
 #include "core/settings/qPrefPartialPressureGas.h"
 #include "profile-widget/diveeventitem.h"
@@ -870,8 +871,8 @@ void ProfileWidget2::pointsRemoved(const QModelIndex &, int start, int end)
 
 void ProfileWidget2::pointsMoved(const QModelIndex &, int start, int end, const QModelIndex &, int row)
 {
-	moveInVector(handles, start, end + 1, row);
-	moveInVector(gases, start, end + 1, row);
+	move_in_range(handles, start, end + 1, row);
+	move_in_range(gases, start, end + 1, row);
 }
 
 void ProfileWidget2::repositionDiveHandlers()
@@ -1319,7 +1320,7 @@ void ProfileWidget2::pictureOffsetChanged(dive *dIn, QString filename, offset_t
 			// Move image from old to new position
 			int oldIndex = oldPos - pictures.begin();
 			int newIndex = newPos - pictures.begin();
-			moveInVector(pictures, oldIndex, oldIndex + 1, newIndex);
+			move_in_range(pictures, oldIndex, oldIndex + 1, newIndex);
 		} else {
 			// Case 1b): remove picture
 			pictures.erase(oldPos);
diff --git a/qt-models/divepicturemodel.cpp b/qt-models/divepicturemodel.cpp
index af2813e78..9abd16192 100644
--- a/qt-models/divepicturemodel.cpp
+++ b/qt-models/divepicturemodel.cpp
@@ -5,6 +5,7 @@
 #include "core/imagedownloader.h"
 #include "core/picture.h"
 #include "core/qthelper.h"
+#include "core/range.h"
 #include "core/selection.h"
 #include "core/subsurface-qt/divelistnotifier.h"
 #include "commands/command.h"
@@ -205,8 +206,8 @@ void DivePictureModel::picturesAdded(dive *d, QVector<PictureObj> picsIn)
 	// Convert the picture-data into our own format
 	std::vector<PictureEntry> pics;
 	pics.reserve(picsIn.size());
-	for (int i = 0; i < picsIn.size(); ++i)
-		pics.push_back(PictureEntry(d, picsIn[i]));
+	for (const PictureObj &pic: picsIn)
+		pics.push_back(PictureEntry(d, pic));
 
 	// Insert batch-wise to avoid too many reloads
 	pictures.reserve(pictures.size() + pics.size());
@@ -241,10 +242,8 @@ int DivePictureModel::rowCount(const QModelIndex&) const
 
 int DivePictureModel::findPictureId(const std::string &filename)
 {
-	for (int i = 0; i < (int)pictures.size(); ++i)
-		if (pictures[i].filename == filename)
-			return i;
-	return -1;
+	return index_of_if(pictures, [&filename](const PictureEntry &p)
+				     { return p.filename == filename; });
 }
 
 static void addDurationToThumbnail(QImage &img, duration_t duration)
@@ -312,6 +311,6 @@ void DivePictureModel::pictureOffsetChanged(dive *d, const QString filenameIn, o
 	if (oldIndex == newIndex || oldIndex + 1 == newIndex)
 		return;
 	beginMoveRows(QModelIndex(), oldIndex, oldIndex, QModelIndex(), newIndex);
-	moveInVector(pictures, oldIndex, oldIndex + 1, newIndex);
+	move_in_range(pictures, oldIndex, oldIndex + 1, newIndex);
 	endMoveRows();
 }
diff --git a/qt-models/diveplannermodel.cpp b/qt-models/diveplannermodel.cpp
index 17be91a29..058bc3821 100644
--- a/qt-models/diveplannermodel.cpp
+++ b/qt-models/diveplannermodel.cpp
@@ -7,6 +7,7 @@
 #include "qt-models/models.h"
 #include "core/device.h"
 #include "core/qthelper.h"
+#include "core/range.h"
 #include "core/sample.h"
 #include "core/settings/qPrefDivePlanner.h"
 #include "core/settings/qPrefUnit.h"
@@ -877,7 +878,7 @@ void DivePlannerPointsModel::editStop(int row, divedatapoint newData)
 
 	if (newRow != row && newRow != row + 1) {
 		beginMoveRows(QModelIndex(), row, row, QModelIndex(), newRow);
-		moveInVector(divepoints, row, row + 1, newRow);
+		move_in_range(divepoints, row, row + 1, newRow);
 		endMoveRows();
 
 		// Account for moving the row backwards in the array.
diff --git a/qt-models/divetripmodel.cpp b/qt-models/divetripmodel.cpp
index 2f35367a3..e55d620df 100644
--- a/qt-models/divetripmodel.cpp
+++ b/qt-models/divetripmodel.cpp
@@ -10,6 +10,7 @@
 #include "core/string-format.h"
 #include "core/trip.h"
 #include "core/qthelper.h"
+#include "core/range.h"
 #include "core/divesite.h"
 #include "core/picture.h"
 #include "core/subsurface-string.h"
@@ -205,8 +206,8 @@ static QPixmap &getPhotoIcon(int idx)
 	if (!icons) {
 		const IconMetrics &im = defaultIconMetrics();
 		icons = std::make_unique<QPixmap[]>(std::size(icon_names));
-		for (size_t i = 0; i < std::size(icon_names); ++i)
-			icons[i] = QIcon(icon_names[i]).pixmap(im.sz_small, im.sz_small);
+		for (auto [i, name]: enumerated_range(icon_names))
+			icons[i] = QIcon(name).pixmap(im.sz_small, im.sz_small);
 	}
 	return icons[idx];
 }
@@ -974,7 +975,7 @@ void DiveTripModelTree::topLevelChanged(int idx)
 	// If index changed, move items
 	if (newIdx != idx && newIdx != idx + 1) {
 		beginMoveRows(QModelIndex(), idx, idx, QModelIndex(), newIdx);
-		moveInVector(items, idx, idx + 1, newIdx);
+		move_in_range(items, idx, idx + 1, newIdx);
 		endMoveRows();
 	}
 
@@ -1007,34 +1008,26 @@ void DiveTripModelTree::addDivesToTrip(int trip, const QVector<dive *> &dives)
 
 int DiveTripModelTree::findTripIdx(const dive_trip *trip) const
 {
-	for (int i = 0; i < (int)items.size(); ++i)
-		if (items[i].d_or_t.trip == trip)
-			return i;
-	return -1;
+	return index_of_if(items, [trip] (const Item &item)
+				  { return item.d_or_t.trip == trip; });
 }
 
 int DiveTripModelTree::findDiveIdx(const dive *d) const
 {
-	for (int i = 0; i < (int)items.size(); ++i)
-		if (items[i].isDive(d))
-			return i;
-	return -1;
+	return index_of_if(items, [d] (const Item &item)
+				  { return item.isDive(d); });
 }
 
 int DiveTripModelTree::findDiveInTrip(int tripIdx, const dive *d) const
 {
-	const Item &item = items[tripIdx];
-	for (int i = 0; i < (int)item.dives.size(); ++i)
-		if (item.dives[i] == d)
-			return i;
-	return -1;
+	return index_of(items[tripIdx].dives, d);
 }
 
 int DiveTripModelTree::findInsertionIndex(const dive_trip *trip) const
 {
 	dive_or_trip d_or_t{ nullptr, (dive_trip *)trip };
-	for (int i = 0; i < (int)items.size(); ++i) {
-		if (dive_or_trip_less_than(d_or_t, items[i].d_or_t))
+	for (auto [i, item]: enumerated_range(items)) {
+		if (dive_or_trip_less_than(d_or_t, item.d_or_t))
 			return i;
 	}
 	return items.size();
@@ -1121,8 +1114,8 @@ static QVector<dive *> visibleDives(const QVector<dive *> &dives)
 #ifdef SUBSURFACE_MOBILE
 int DiveTripModelTree::tripInDirection(const struct dive *d, int direction) const
 {
-	for (int i = 0; i < (int)items.size(); ++i) {
-		if (items[i].d_or_t.dive == d || (items[i].d_or_t.trip && findDiveInTrip(i, d) != -1)) {
+	for (auto [i, item]: enumerated_range(items)) {
+		if (item.d_or_t.dive == d || (item.d_or_t.trip && findDiveInTrip(i, d) != -1)) {
 			// now walk in the direction given to find a trip
 			int offset = direction;
 			while (i + offset >= 0 && i + offset < (int)items.size()) {
@@ -1405,8 +1398,8 @@ void DiveTripModelTree::divesSelectedTrip(dive_trip *trip, const QVector<dive *>
 		// Since both lists are sorted, we can do this linearly. Perhaps a binary search
 		// would be better?
 		int j = 0; // Index in items array
-		for (int i = 0; i < dives.size(); ++i) {
-			while (j < (int)items.size() && !items[j].isDive(dives[i]))
+		for (struct dive *dive: dives) {
+			while (j < (int)items.size() && !items[j].isDive(dive))
 				++j;
 			if (j >= (int)items.size())
 				break;
@@ -1426,8 +1419,8 @@ void DiveTripModelTree::divesSelectedTrip(dive_trip *trip, const QVector<dive *>
 		// would be better?
 		int j = 0; // Index in items array
 		const Item &entry = items[idx];
-		for (int i = 0; i < dives.size(); ++i) {
-			while (j < (int)entry.dives.size() && entry.dives[j] != dives[i])
+		for (struct dive *dive: dives) {
+			while (j < (int)entry.dives.size() && entry.dives[j] != dive)
 				++j;
 			if (j >= (int)entry.dives.size())
 				break;
@@ -1662,8 +1655,8 @@ void DiveTripModelList::divesSelected(const QVector<dive *> &divesIn)
 	// Since both lists are sorted, we can do this linearly. Perhaps a binary search
 	// would be better?
 	int j = 0; // Index in items array
-	for (int i = 0; i < dives.size(); ++i) {
-		while (j < (int)items.size() && items[j] != dives[i])
+	for (struct dive *dive: dives) {
+		while (j < (int)items.size() && items[j] != dive)
 			++j;
 		if (j >= (int)items.size())
 			break;