diff --git a/Telegram/SourceFiles/apiwrap.cpp b/Telegram/SourceFiles/apiwrap.cpp
index 0f7acc35a..65cf0717e 100644
--- a/Telegram/SourceFiles/apiwrap.cpp
+++ b/Telegram/SourceFiles/apiwrap.cpp
@@ -42,11 +42,10 @@ ApiWrap::ApiWrap(QObject *parent) : QObject(parent)
 void ApiWrap::init() {
 }
 
-void ApiWrap::requestMessageData(ChannelData *channel, MsgId msgId, std_::unique_ptr<RequestMessageDataCallback> callback) {
+void ApiWrap::requestMessageData(ChannelData *channel, MsgId msgId, RequestMessageDataCallback &&callback) {
 	MessageDataRequest &req(channel ? _channelMessageDataRequests[channel][msgId] : _messageDataRequests[msgId]);
 	if (callback) {
-		MessageDataRequest::CallbackPtr pcallback(callback.release());
-		req.callbacks.append(pcallback);
+		req.callbacks.append(std_::move(callback));
 	}
 	if (!req.req) _messageDataResolveDelayed->call();
 }
@@ -138,7 +137,7 @@ void ApiWrap::gotMessageDatas(ChannelData *channel, const MTPmessages_Messages &
 		for (auto i = requests->begin(); i != requests->cend();) {
 			if (i.value().req == req) {
 				for_const (auto &callback, i.value().callbacks) {
-					callback->call(channel, i.key());
+					callback(channel, i.key());
 				}
 				i = requests->erase(i);
 			} else {
diff --git a/Telegram/SourceFiles/apiwrap.h b/Telegram/SourceFiles/apiwrap.h
index e4c83a8d6..524f195c6 100644
--- a/Telegram/SourceFiles/apiwrap.h
+++ b/Telegram/SourceFiles/apiwrap.h
@@ -28,8 +28,8 @@ public:
 	ApiWrap(QObject *parent);
 	void init();
 
-	using RequestMessageDataCallback = SharedCallback<void, ChannelData*, MsgId>;
-	void requestMessageData(ChannelData *channel, MsgId msgId, std_::unique_ptr<RequestMessageDataCallback> callback);
+	using RequestMessageDataCallback = base::lambda_wrap<void(ChannelData*, MsgId)>;
+	void requestMessageData(ChannelData *channel, MsgId msgId, RequestMessageDataCallback &&callback);
 
 	void requestFullPeer(PeerData *peer);
 	void requestPeer(PeerData *peer);
@@ -82,11 +82,8 @@ private:
 
 	void gotMessageDatas(ChannelData *channel, const MTPmessages_Messages &result, mtpRequestId req);
 	struct MessageDataRequest {
-		MessageDataRequest() : req(0) {
-		}
-		typedef SharedCallback<void, ChannelData*, MsgId>::Ptr CallbackPtr;
-		typedef QList<CallbackPtr> Callbacks;
-		mtpRequestId req;
+		using Callbacks = QList<RequestMessageDataCallback>;
+		mtpRequestId req = 0;
 		Callbacks callbacks;
 	};
 	typedef QMap<MsgId, MessageDataRequest> MessageDataRequests;
diff --git a/Telegram/SourceFiles/boxes/sharebox.cpp b/Telegram/SourceFiles/boxes/sharebox.cpp
index 37084e249..19b249b36 100644
--- a/Telegram/SourceFiles/boxes/sharebox.cpp
+++ b/Telegram/SourceFiles/boxes/sharebox.cpp
@@ -227,9 +227,9 @@ void ShareBox::onMustScrollTo(int top, int bottom) {
 		to = bottom - (scrollBottom - scrollTop);
 	}
 	if (from != to) {
-		START_ANIMATION(_scrollAnimation, func([this]() {
+		_scrollAnimation.start([this]() {
 			scrollArea()->scrollToY(_scrollAnimation.current(scrollArea()->scrollTop()));
-		}), from, to, st::shareScrollDuration, anim::sineInOut);
+		}, from, to, st::shareScrollDuration, anim::sineInOut);
 	}
 }
 
@@ -437,9 +437,9 @@ void ShareInner::setActive(int active) {
 	if (active != _active) {
 		auto changeNameFg = [this](int index, style::color from, style::color to) {
 			if (auto chat = getChatAtIndex(index)) {
-				START_ANIMATION(chat->nameFg, func([this, chat] {
+				chat->nameFg.start([this, chat] {
 					repaintChat(chat->peer);
-				}), from->c, to->c, st::shareActivateDuration, anim::linear);
+				}, from->c, to->c, st::shareActivateDuration);
 			}
 		};
 		changeNameFg(_active, st::shareNameActiveFg, st::shareNameFg);
@@ -459,16 +459,7 @@ void ShareInner::paintChat(Painter &p, Chat *chat, int index) {
 	auto w = width();
 	auto photoLeft = (_rowWidth - (st::sharePhotoRadius * 2)) / 2;
 	auto photoTop = st::sharePhotoTop;
-	if (chat->selection.isNull()) {
-		if (!chat->wideUserpicCache.isNull()) {
-			chat->wideUserpicCache = QPixmap();
-		}
-		auto userpicRadius = chat->selected ? st::sharePhotoSmallRadius : st::sharePhotoRadius;
-		auto userpicShift = st::sharePhotoRadius - userpicRadius;
-		auto userpicLeft = x + photoLeft + userpicShift;
-		auto userpicTop = y + photoTop + userpicShift;
-		chat->peer->paintUserpicLeft(p, userpicRadius * 2, userpicLeft, userpicTop, w);
-	} else {
+	if (chat->selection.animating()) {
 		p.setRenderHint(QPainter::SmoothPixmapTransform, true);
 		auto userpicRadius = qRound(WideCacheScale * (st::sharePhotoRadius + (st::sharePhotoSmallRadius - st::sharePhotoRadius) * selectionLevel));
 		auto userpicShift = WideCacheScale * st::sharePhotoRadius - userpicRadius;
@@ -478,6 +469,15 @@ void ShareInner::paintChat(Painter &p, Chat *chat, int index) {
 		auto from = QRect(QPoint(0, 0), chat->wideUserpicCache.size());
 		p.drawPixmapLeft(to, w, chat->wideUserpicCache, from);
 		p.setRenderHint(QPainter::SmoothPixmapTransform, false);
+	} else {
+		if (!chat->wideUserpicCache.isNull()) {
+			chat->wideUserpicCache = QPixmap();
+		}
+		auto userpicRadius = chat->selected ? st::sharePhotoSmallRadius : st::sharePhotoRadius;
+		auto userpicShift = st::sharePhotoRadius - userpicRadius;
+		auto userpicLeft = x + photoLeft + userpicShift;
+		auto userpicTop = y + photoTop + userpicShift;
+		chat->peer->paintUserpicLeft(p, userpicRadius * 2, userpicLeft, userpicTop, w);
 	}
 
 	if (selectionLevel > 0) {
@@ -516,11 +516,12 @@ void ShareInner::paintChat(Painter &p, Chat *chat, int index) {
 	p.setRenderHint(QPainter::SmoothPixmapTransform, false);
 	p.setOpacity(1.);
 
-	if (chat->nameFg.isNull()) {
-		p.setPen((index == _active) ? st::shareNameActiveFg : st::shareNameFg);
-	} else {
+	if (chat->nameFg.animating()) {
 		p.setPen(chat->nameFg.current());
+	} else {
+		p.setPen((index == _active) ? st::shareNameActiveFg : st::shareNameFg);
 	}
+
 	auto nameWidth = (_rowWidth - st::shareColumnSkip);
 	auto nameLeft = st::shareColumnSkip / 2;
 	auto nameTop = photoTop + st::sharePhotoRadius * 2 + st::shareNameTop;
@@ -670,21 +671,21 @@ void ShareInner::changeCheckState(Chat *chat) {
 	if (chat->selected) {
 		_selected.insert(chat->peer);
 		chat->icons.push_back(Chat::Icon());
-		START_ANIMATION(chat->icons.back().fadeIn, func([this, chat] {
+		chat->icons.back().fadeIn.start([this, chat] {
 			repaintChat(chat->peer);
-		}), 0, 1, st::shareSelectDuration, anim::linear);
+		}, 0, 1, st::shareSelectDuration);
 	} else {
 		_selected.remove(chat->peer);
 		prepareWideCheckIconCache(&chat->icons.back());
-		START_ANIMATION(chat->icons.back().fadeOut, func([this, chat] {
-			removeFadeOutedIcons(chat);
+		chat->icons.back().fadeOut.start([this, chat] {
 			repaintChat(chat->peer);
-		}), 1, 0, st::shareSelectDuration, anim::linear);
+			removeFadeOutedIcons(chat); // this call can destroy current lambda
+		}, 1, 0, st::shareSelectDuration);
 	}
 	prepareWideUserpicCache(chat);
-	START_ANIMATION(chat->selection, func([this, chat] {
+	chat->selection.start([this, chat] {
 		repaintChat(chat->peer);
-	}), chat->selected ? 0 : 1, chat->selected ? 1 : 0, st::shareSelectDuration, anim_bumpy);
+	}, chat->selected ? 0 : 1, chat->selected ? 1 : 0, st::shareSelectDuration, anim_bumpy);
 	if (chat->selected) {
 		setActive(chatIndex(chat->peer));
 	}
@@ -692,9 +693,9 @@ void ShareInner::changeCheckState(Chat *chat) {
 }
 
 void ShareInner::removeFadeOutedIcons(Chat *chat) {
-	while (!chat->icons.empty() && chat->icons.front().fadeIn.isNull() && chat->icons.front().fadeOut.isNull()) {
+	while (!chat->icons.empty() && !chat->icons.front().fadeIn.animating() && !chat->icons.front().fadeOut.animating()) {
 		if (chat->icons.size() > 1 || !chat->selected) {
-			chat->icons.pop_front();
+			chat->icons.erase(chat->icons.begin());
 		} else {
 			break;
 		}
@@ -1016,18 +1017,6 @@ void shareGameScoreFromItem(HistoryItem *item) {
 	Ui::showLayer(new ShareBox(std_::move(copyCallback), std_::move(submitCallback)));
 }
 
-class GameMessageResolvedCallback : public SharedCallback<void, ChannelData*, MsgId> {
-public:
-	void call(ChannelData *channel, MsgId msgId) const override {
-		if (auto item = App::histItemById(channel, msgId)) {
-			shareGameScoreFromItem(item);
-		} else {
-			Ui::showLayer(new InformBox(lang(lng_edit_deleted)));
-		}
-	}
-
-};
-
 } // namespace
 
 void shareGameScoreByHash(const QString &hash) {
@@ -1062,7 +1051,13 @@ void shareGameScoreByHash(const QString &hash) {
 	} else if (App::api()) {
 		auto channel = channelId ? App::channelLoaded(channelId) : nullptr;
 		if (channel || !channelId) {
-			App::api()->requestMessageData(channel, msgId, std_::make_unique<GameMessageResolvedCallback>());
+			App::api()->requestMessageData(channel, msgId, [](ChannelData *channel, MsgId msgId) {
+				if (auto item = App::histItemById(channel, msgId)) {
+					shareGameScoreFromItem(item);
+				} else {
+					Ui::showLayer(new InformBox(lang(lng_edit_deleted)));
+				}
+			});
 		}
 	}
 }
diff --git a/Telegram/SourceFiles/boxes/sharebox.h b/Telegram/SourceFiles/boxes/sharebox.h
index 696a28242..675fb92aa 100644
--- a/Telegram/SourceFiles/boxes/sharebox.h
+++ b/Telegram/SourceFiles/boxes/sharebox.h
@@ -23,6 +23,7 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 #include "abstractbox.h"
 #include "core/lambda_wrap.h"
 #include "core/observer.h"
+#include "core/vector_of_moveable.h"
 
 namespace Dialogs {
 class Row;
@@ -163,7 +164,7 @@ private:
 			FloatAnimation fadeOut;
 			QPixmap wideCheckCache;
 		};
-		QList<Icon> icons;
+		std_::vector_of_moveable<Icon> icons;
 	};
 	void paintChat(Painter &p, Chat *chat, int index);
 	void updateChat(PeerData *peer);
diff --git a/Telegram/SourceFiles/boxes/stickersetbox.cpp b/Telegram/SourceFiles/boxes/stickersetbox.cpp
index 0f9974954..728cee690 100644
--- a/Telegram/SourceFiles/boxes/stickersetbox.cpp
+++ b/Telegram/SourceFiles/boxes/stickersetbox.cpp
@@ -62,8 +62,8 @@ void StickerSetInner::gotSet(const MTPmessages_StickerSet &set) {
 	_selected = -1;
 	setCursor(style::cur_default);
 	if (set.type() == mtpc_messages_stickerSet) {
-		auto &d(set.c_messages_stickerSet());
-		auto &v(d.vdocuments.c_vector().v);
+		auto &d = set.c_messages_stickerSet();
+		auto &v = d.vdocuments.c_vector().v;
 		_pack.reserve(v.size());
 		_packOvers.reserve(v.size());
 		for (int i = 0, l = v.size(); i < l; ++i) {
@@ -247,13 +247,13 @@ void StickerSetInner::updateSelected() {
 
 void StickerSetInner::startOverAnimation(int index, float64 from, float64 to) {
 	if (index >= 0 && index < _packOvers.size()) {
-		START_ANIMATION(_packOvers[index], func([this, index]() {
+		_packOvers[index].start([this, index] {
 			int row = index / StickerPanPerRow;
 			int column = index % StickerPanPerRow;
 			int left = st::stickersPadding.left() + column * st::stickersSize.width();
 			int top = st::stickersPadding.top() + row * st::stickersSize.height();
 			rtlupdate(left, top, st::stickersSize.width(), st::stickersSize.height());
-		}), from, to, st::emojiPanDuration, anim::linear);
+		}, from, to, st::emojiPanDuration);
 	}
 }
 
diff --git a/Telegram/SourceFiles/boxes/stickersetbox.h b/Telegram/SourceFiles/boxes/stickersetbox.h
index 699780a97..3c7a936a3 100644
--- a/Telegram/SourceFiles/boxes/stickersetbox.h
+++ b/Telegram/SourceFiles/boxes/stickersetbox.h
@@ -21,6 +21,7 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 #pragma once
 
 #include "abstractbox.h"
+#include "core/vector_of_moveable.h"
 
 class ConfirmBox;
 
@@ -69,7 +70,7 @@ private:
 		return (_setFlags & MTPDstickerSet::Flag::f_masks);
 	}
 
-	QVector<FloatAnimation> _packOvers;
+	std_::vector_of_moveable<FloatAnimation> _packOvers;
 	StickerPack _pack;
 	StickersByEmojiMap _emoji;
 	bool _loaded = false;
diff --git a/Telegram/SourceFiles/core/basic_types.h b/Telegram/SourceFiles/core/basic_types.h
index 68dd42b2e..778aff01b 100644
--- a/Telegram/SourceFiles/core/basic_types.h
+++ b/Telegram/SourceFiles/core/basic_types.h
@@ -20,6 +20,17 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 */
 #pragma once
 
+#include <string>
+#include <exception>
+
+#include <QtCore/QReadWriteLock>
+
+#include <ctime>
+
+#ifndef OS_MAC_OLD
+#include <memory>
+#endif // OS_MAC_OLD
+
 template <typename T>
 void deleteAndMark(T *&link) {
 	delete link;
@@ -259,13 +270,6 @@ typedef float float32;
 typedef double float64;
 #endif
 
-#include <string>
-#include <exception>
-
-#include <QtCore/QReadWriteLock>
-
-#include <ctime>
-
 using std::string;
 using std::exception;
 #ifdef OS_MAC_OLD
@@ -1035,13 +1039,15 @@ struct ComponentWrapStruct {
 	// global scope, so it will be filled by zeros from the start
 	ComponentWrapStruct() {
 	}
-	ComponentWrapStruct(int size, ComponentConstruct construct, ComponentDestruct destruct, ComponentMove move)
+	ComponentWrapStruct(std::size_t size, std::size_t align, ComponentConstruct construct, ComponentDestruct destruct, ComponentMove move)
 	: Size(size)
+	, Align(align)
 	, Construct(construct)
 	, Destruct(destruct)
 	, Move(move) {
 	}
-	int Size;
+	std::size_t Size;
+	std::size_t Align;
 	ComponentConstruct Construct;
 	ComponentDestruct Destruct;
 	ComponentMove Move;
@@ -1058,6 +1064,7 @@ extern QAtomicInt ComponentIndexLast;
 template <typename Type>
 struct BaseComponent {
 	BaseComponent() {
+		static_assert(alignof(Type) <= sizeof(SmallestSizeType), "Components should align to a pointer!");
 	}
 	BaseComponent(const BaseComponent &other) = delete;
 	BaseComponent &operator=(const BaseComponent &other) = delete;
@@ -1075,8 +1082,11 @@ struct BaseComponent {
 				t_assert(last < 64);
 				if (_index.testAndSetOrdered(0, last + 1)) {
 					ComponentWraps[last] = ComponentWrapStruct(
-						CeilDivideMinimumOne<sizeof(Type), sizeof(uint64)>::Result * sizeof(uint64),
-						Type::ComponentConstruct, Type::ComponentDestruct, Type::ComponentMove);
+						CeilDivideMinimumOne<sizeof(Type), sizeof(SmallestSizeType)>::Result * sizeof(SmallestSizeType),
+						alignof(Type),
+						Type::ComponentConstruct,
+						Type::ComponentDestruct,
+						Type::ComponentMove);
 				}
 				break;
 			}
@@ -1088,6 +1098,8 @@ struct BaseComponent {
 	}
 
 protected:
+	using SmallestSizeType = void*;
+
 	static void ComponentConstruct(void *location, Composer *composer) {
 		new (location) Type();
 	}
@@ -1102,7 +1114,6 @@ protected:
 
 class ComposerMetadata {
 public:
-
 	ComposerMetadata(uint64 mask) : size(0), last(64), _mask(mask) {
 		for (int i = 0; i < 64; ++i) {
 			uint64 m = (1ULL << i);
@@ -1147,15 +1158,13 @@ const ComposerMetadata *GetComposerMetadata(uint64 mask);
 
 class Composer {
 public:
-
 	Composer(uint64 mask = 0) : _data(zerodata()) {
 		if (mask) {
 			const ComposerMetadata *meta = GetComposerMetadata(mask);
 			int size = sizeof(meta) + meta->size;
-			void *data = operator new(size);
-			if (!data) { // terminate if we can't allocate memory
-				throw "Can't allocate memory!";
-			}
+
+			auto data = operator new(size);
+			t_assert(data != nullptr);
 
 			_data = data;
 			_meta() = meta;
@@ -1163,7 +1172,13 @@ public:
 				int offset = meta->offsets[i];
 				if (offset >= 0) {
 					try {
-						ComponentWraps[i].Construct(_dataptrunsafe(offset), this);
+						auto constructAt = _dataptrunsafe(offset);
+#ifndef OS_MAC_OLD
+						auto space = ComponentWraps[i].Size;
+						auto alignedAt = std::align(ComponentWraps[i].Align, space, constructAt, space);
+						t_assert(alignedAt == constructAt);
+#endif // OS_MAC_OLD
+						ComponentWraps[i].Construct(constructAt, this);
 					} catch (...) {
 						while (i > 0) {
 							--i;
@@ -1182,7 +1197,7 @@ public:
 	Composer &operator=(const Composer &other) = delete;
 	~Composer() {
 		if (_data != zerodata()) {
-			const ComposerMetadata *meta = _meta();
+			auto meta = _meta();
 			for (int i = 0; i < meta->last; ++i) {
 				int offset = meta->offsets[i];
 				if (offset >= 0) {
@@ -1213,7 +1228,7 @@ protected:
 			Composer tmp(mask);
 			tmp.swap(*this);
 			if (_data != zerodata() && tmp._data != zerodata()) {
-				const ComposerMetadata *meta = _meta(), *wasmeta = tmp._meta();
+				auto meta = _meta(), wasmeta = tmp._meta();
 				for (int i = 0; i < meta->last; ++i) {
 					int offset = meta->offsets[i], wasoffset = wasmeta->offsets[i];
 					if (offset >= 0 && wasoffset >= 0) {
@@ -1252,103 +1267,3 @@ private:
 	}
 
 };
-
-template <typename R, typename... Args>
-class SharedCallback {
-public:
-	virtual R call(Args... args) const = 0;
-	virtual ~SharedCallback() {
-	}
-	using Ptr = QSharedPointer<SharedCallback<R, Args...>>;
-
-};
-
-template <typename R, typename... Args>
-class FunctionImplementation {
-public:
-	virtual R call(Args... args) = 0;
-	virtual void destroy() { delete this; }
-	virtual ~FunctionImplementation() {}
-
-};
-
-template <typename R, typename... Args>
-class NullFunctionImplementation : public FunctionImplementation<R, Args...> {
-public:
-	R call(Args... args) override { return R(); }
-	void destroy() override {}
-	static NullFunctionImplementation<R, Args...> SharedInstance;
-
-};
-template <typename R, typename... Args>
-NullFunctionImplementation<R, Args...> NullFunctionImplementation<R, Args...>::SharedInstance;
-
-template <typename R, typename... Args>
-class Function {
-public:
-	Function() : _implementation(nullImpl()) {}
-	Function(FunctionImplementation<R, Args...> *implementation) : _implementation(implementation) {}
-	Function(const Function<R, Args...> &other) = delete;
-	Function<R, Args...> &operator=(const Function<R, Args...> &other) = delete;
-	Function(Function<R, Args...> &&other) : _implementation(other._implementation) {
-		other._implementation = nullImpl();
-	}
-	Function<R, Args...> &operator=(Function<R, Args...> &&other) {
-		std::swap(_implementation, other._implementation);
-		return *this;
-	}
-
-	bool isNull() const {
-		return (_implementation == nullImpl());
-	}
-
-	R call(Args... args) { return _implementation->call(args...); }
-	~Function() {
-		if (_implementation) {
-			_implementation->destroy();
-			_implementation = nullptr;
-		}
-		deleteAndMark(_implementation);
-	}
-
-private:
-	static FunctionImplementation<R, Args...> *nullImpl() {
-		return &NullFunctionImplementation<R, Args...>::SharedInstance;
-	}
-
-	FunctionImplementation<R, Args...> *_implementation;
-
-};
-
-template <typename R, typename... Args>
-class WrappedFunction : public FunctionImplementation<R, Args...> {
-public:
-	using Method = R(*)(Args... args);
-	WrappedFunction(Method method) : _method(method) {}
-	R call(Args... args) override { return (*_method)(args...); }
-
-private:
-	Method _method;
-
-};
-template <typename R, typename... Args>
-inline Function<R, Args...> func(R(*method)(Args... args)) {
-	return Function<R, Args...>(new WrappedFunction<R, Args...>(method));
-}
-
-template <typename O, typename I, typename R, typename... Args>
-class ObjectFunction : public FunctionImplementation<R, Args...> {
-public:
-	using Method = R(I::*)(Args... args);
-	ObjectFunction(O *obj, Method method) : _obj(obj), _method(method) {}
-	R call(Args... args) override { return (_obj->*_method)(args...); }
-
-private:
-	O *_obj;
-	Method _method;
-
-};
-template <typename O, typename I, typename R, typename... Args>
-inline Function<R, Args...> func(O *obj, R(I::*method)(Args...)) {
-	return Function<R, Args...>(new ObjectFunction<O, I, R, Args...>(obj, method));
-}
diff --git a/Telegram/SourceFiles/core/lambda_wrap.h b/Telegram/SourceFiles/core/lambda_wrap.h
index 77982086c..9bc1fe084 100644
--- a/Telegram/SourceFiles/core/lambda_wrap.h
+++ b/Telegram/SourceFiles/core/lambda_wrap.h
@@ -373,48 +373,20 @@ public:
 
 } // namespace base
 
-// While we still use Function<>
+// While we still use rpcDone() and rpcFail()
+
+#include "mtproto/rpc_sender.h"
 
 template <typename FunctionType>
-struct LambdaFunctionHelper;
+struct LambdaUniqueHelper;
 
 template <typename Lambda, typename R, typename ...Args>
-struct LambdaFunctionHelper<R(Lambda::*)(Args...) const> {
-	using FunctionType = Function<R, Args...>;
+struct LambdaUniqueHelper<R(Lambda::*)(Args...) const> {
 	using UniqueType = base::lambda_unique<R(Args...)>;
 };
 
 template <typename FunctionType>
-using LambdaGetFunction = typename LambdaFunctionHelper<FunctionType>::FunctionType;
-
-template <typename FunctionType>
-using LambdaGetUnique = typename LambdaFunctionHelper<FunctionType>::UniqueType;
-
-template <typename R, typename ...Args>
-class LambdaFunctionImplementation : public FunctionImplementation<R, Args...> {
-public:
-	LambdaFunctionImplementation(base::lambda_unique<R(Args...)> &&lambda) : _lambda(std_::move(lambda)) {
-	}
-	R call(Args... args) override { return _lambda(std_::forward<Args>(args)...); }
-
-private:
-	base::lambda_unique<R(Args...)> _lambda;
-
-};
-
-template <typename R, typename ...Args>
-inline Function<R, Args...> func_lambda_wrap_helper(base::lambda_unique<R(Args...)> &&lambda) {
-	return Function<R, Args...>(new LambdaFunctionImplementation<R, Args...>(std_::move(lambda)));
-}
-
-template <typename Lambda, typename = std_::enable_if_t<std_::is_rvalue_reference<Lambda&&>::value>>
-inline LambdaGetFunction<decltype(&Lambda::operator())> func(Lambda &&lambda) {
-	return func_lambda_wrap_helper(LambdaGetUnique<decltype(&Lambda::operator())>(std_::move(lambda)));
-}
-
-// While we still use rpcDone() and rpcFail()
-
-#include "mtproto/rpc_sender.h"
+using LambdaGetUnique = typename LambdaUniqueHelper<FunctionType>::UniqueType;
 
 template <typename Base, typename FunctionType>
 class RPCHandlerImplementation : public Base {
diff --git a/Telegram/SourceFiles/core/observer.h b/Telegram/SourceFiles/core/observer.h
index f37494625..97665a294 100644
--- a/Telegram/SourceFiles/core/observer.h
+++ b/Telegram/SourceFiles/core/observer.h
@@ -58,7 +58,7 @@ private:
 
 };
 
-// Handler is one of Function<> instantiations.
+// Handler is one of base::lambda_unique<> instantiations.
 template <typename Flags, typename Handler>
 struct ObserversList {
 	struct Entry {
@@ -109,8 +109,8 @@ public:
 		// entries list while the loop is still running.
 		for (int i = 0; i < entries.size(); ++i) {
 			auto &entry = entries[i];
-			if (!entry.handler.isNull() && (flags & entry.flags)) {
-				entry.handler.call(std_::forward<Args>(args)...);
+			if (entry.handler && (flags & entry.flags)) {
+				entry.handler(std_::forward<Args>(args)...);
 			}
 		}
 	}
@@ -140,7 +140,7 @@ private:
 		if (entries.size() <= connectionIndex) return;
 
 		if (entries.size() == connectionIndex + 1) {
-			for (entries.pop_back(); !entries.isEmpty() && entries.back().handler.isNull();) {
+			for (entries.pop_back(); !entries.isEmpty() && !entries.back().handler;) {
 				entries.pop_back();
 			}
 		} else {
diff --git a/Telegram/SourceFiles/core/vector_of_moveable.h b/Telegram/SourceFiles/core/vector_of_moveable.h
index 861b184ec..7077237d4 100644
--- a/Telegram/SourceFiles/core/vector_of_moveable.h
+++ b/Telegram/SourceFiles/core/vector_of_moveable.h
@@ -93,6 +93,7 @@ public:
 			*prev = std_::move(*next);
 		}
 		--_size;
+		end()->~T();
 		return it;
 	}
 
@@ -143,15 +144,21 @@ public:
 	}
 	inline const T &at(int index) const {
 		if (index < 0 || index >= _size) {
-#if QT_VERSION < QT_VERSION_CHECK(5, 5, 0)
-			throw std::exception();
-#else // QT_VERSION < 5.5.0
+#ifndef OS_MAC_OLD
 			throw std::out_of_range("");
-#endif // QT_VERSION < 5.5.0
+#else // OS_MAC_OLD
+			throw std::exception();
+#endif // OS_MAC_OLD
 		}
 		return data()[index];
 	}
 
+	void reserve(int newCapacity) {
+		if (newCapacity > _capacity) {
+			reallocate(newCapacity);
+		}
+	}
+
 	inline ~vector_of_moveable() {
 		clear();
 	}
diff --git a/Telegram/SourceFiles/history.cpp b/Telegram/SourceFiles/history.cpp
index be131950d..59281428e 100644
--- a/Telegram/SourceFiles/history.cpp
+++ b/Telegram/SourceFiles/history.cpp
@@ -2644,10 +2644,12 @@ void HistoryMessageReplyMarkup::create(const MTPReplyMarkup &markup) {
 	}
 }
 
-void HistoryDependentItemCallback::call(ChannelData *channel, MsgId msgId) const {
-	if (HistoryItem *item = App::histItemById(_dependent)) {
-		item->updateDependencyItem();
-	}
+ApiWrap::RequestMessageDataCallback historyDependentItemCallback(const FullMsgId &msgId) {
+	return [dependent = msgId](ChannelData *channel, MsgId msgId) {
+		if (HistoryItem *item = App::histItemById(dependent)) {
+			item->updateDependencyItem();
+		}
+	};
 }
 
 void HistoryMessageUnreadBar::init(int count) {
@@ -4910,7 +4912,9 @@ bool HistoryGif::playInline(bool autoplay) {
 		if (!cAutoPlayGif()) {
 			App::stopGifItems();
 		}
-		_gif = new Media::Clip::Reader(_data->location(), _data->data(), func(_parent, &HistoryItem::clipCallback));
+		_gif = new Media::Clip::Reader(_data->location(), _data->data(), [this](Media::Clip::Notification notification) {
+			_parent->clipCallback(notification);
+		});
 		App::regGifItem(_gif, _parent);
 		if (gif()) _gif->setAutoplay();
 	}
@@ -6837,7 +6841,7 @@ void HistoryMessage::createComponents(const CreateConfig &config) {
 	if (auto reply = Get<HistoryMessageReply>()) {
 		reply->replyToMsgId = config.replyTo;
 		if (!reply->updateData(this) && App::api()) {
-			App::api()->requestMessageData(history()->peer->asChannel(), reply->replyToMsgId, std_::make_unique<HistoryDependentItemCallback>(fullId()));
+			App::api()->requestMessageData(history()->peer->asChannel(), reply->replyToMsgId, historyDependentItemCallback(fullId()));
 		}
 	}
 	if (auto via = Get<HistoryMessageVia>()) {
@@ -8388,7 +8392,7 @@ void HistoryService::createFromMtp(const MTPDmessageService &message) {
 		if (auto dependent = GetDependentData()) {
 			dependent->msgId = message.vreply_to_msg_id.v;
 			if (!updateDependent() && App::api()) {
-				App::api()->requestMessageData(history()->peer->asChannel(), dependent->msgId, std_::make_unique<HistoryDependentItemCallback>(fullId()));
+				App::api()->requestMessageData(history()->peer->asChannel(), dependent->msgId, historyDependentItemCallback(fullId()));
 			}
 		}
 	}
diff --git a/Telegram/SourceFiles/history.h b/Telegram/SourceFiles/history.h
index b6119cd76..ecba44ef3 100644
--- a/Telegram/SourceFiles/history.h
+++ b/Telegram/SourceFiles/history.h
@@ -935,17 +935,6 @@ private:
 	StylePtr _st;
 };
 
-class HistoryDependentItemCallback : public SharedCallback<void, ChannelData*, MsgId> {
-public:
-	HistoryDependentItemCallback(FullMsgId dependent) : _dependent(dependent) {
-	}
-	void call(ChannelData *channel, MsgId msgId) const override;
-
-private:
-	FullMsgId _dependent;
-
-};
-
 // any HistoryItem can have this Interface for
 // displaying the day mark above the message
 struct HistoryMessageDate : public BaseComponent<HistoryMessageDate> {
diff --git a/Telegram/SourceFiles/historywidget.cpp b/Telegram/SourceFiles/historywidget.cpp
index ccf5631df..9b38e8eb5 100644
--- a/Telegram/SourceFiles/historywidget.cpp
+++ b/Telegram/SourceFiles/historywidget.cpp
@@ -101,6 +101,14 @@ public:
 
 constexpr int ScrollDateHideTimeout = 1000;
 
+ApiWrap::RequestMessageDataCallback replyEditMessageDataCallback() {
+	return [](ChannelData *channel, MsgId msgId) {
+		if (App::main()) {
+			App::main()->messageDataReceived(channel, msgId);
+		}
+	};
+}
+
 } // namespace
 
 // flick scroll taken from http://qt-project.org/doc/qt-4.8/demos-embedded-anomaly-src-flickcharm-cpp.html
@@ -1684,7 +1692,7 @@ void HistoryInner::toggleScrollDateShown() {
 	_scrollDateShown = !_scrollDateShown;
 	auto from = _scrollDateShown ? 0. : 1.;
 	auto to = _scrollDateShown ? 1. : 0.;
-	START_ANIMATION(_scrollDateOpacity, func(this, &HistoryInner::repaintScrollDateCallback), from, to, st::btnAttachEmoji.duration, anim::linear);
+	_scrollDateOpacity.start([this] { repaintScrollDateCallback(); }, from, to, st::btnAttachEmoji.duration);
 }
 
 void HistoryInner::repaintScrollDateCallback() {
@@ -4117,7 +4125,7 @@ void HistoryWidget::applyDraft(bool parseLinks) {
 	if (_editMsgId || _replyToId) {
 		updateReplyEditTexts();
 		if (!_replyEditMsg && App::api()) {
-			App::api()->requestMessageData(_peer->asChannel(), _editMsgId ? _editMsgId : _replyToId, std_::make_unique<ReplyEditMessageDataCallback>());
+			App::api()->requestMessageData(_peer->asChannel(), _editMsgId ? _editMsgId : _replyToId, replyEditMessageDataCallback());
 		}
 	}
 }
@@ -7633,7 +7641,7 @@ bool HistoryWidget::pinnedMsgVisibilityUpdated() {
 			update();
 		}
 		if (!_pinnedBar->msg && App::api()) {
-			App::api()->requestMessageData(_peer->asChannel(), _pinnedBar->msgId, std_::make_unique<ReplyEditMessageDataCallback>());
+			App::api()->requestMessageData(_peer->asChannel(), _pinnedBar->msgId, replyEditMessageDataCallback());
 		}
 	} else if (_pinnedBar) {
 		destroyPinnedBar();
@@ -7652,12 +7660,6 @@ void HistoryWidget::destroyPinnedBar() {
 	_inPinnedMsg = false;
 }
 
-void HistoryWidget::ReplyEditMessageDataCallback::call(ChannelData *channel, MsgId msgId) const {
-	if (App::main()) {
-		App::main()->messageDataReceived(channel, msgId);
-	}
-}
-
 bool HistoryWidget::sendExistingDocument(DocumentData *doc, const QString &caption) {
 	if (!_history || !doc || !canSendMessages(_peer)) {
 		return false;
diff --git a/Telegram/SourceFiles/historywidget.h b/Telegram/SourceFiles/historywidget.h
index e87585120..ab8d8282c 100644
--- a/Telegram/SourceFiles/historywidget.h
+++ b/Telegram/SourceFiles/historywidget.h
@@ -908,11 +908,6 @@ private:
 	void destroyPinnedBar();
 	void unpinDone(const MTPUpdates &updates);
 
-	class ReplyEditMessageDataCallback : public SharedCallback<void, ChannelData*, MsgId> {
-	public:
-		void call(ChannelData *channel, MsgId msgId) const override;
-	};
-
 	bool sendExistingDocument(DocumentData *doc, const QString &caption);
 	void sendExistingPhoto(PhotoData *photo, const QString &caption);
 
diff --git a/Telegram/SourceFiles/inline_bots/inline_bot_layout_internal.cpp b/Telegram/SourceFiles/inline_bots/inline_bot_layout_internal.cpp
index 06b1e07be..49a70a392 100644
--- a/Telegram/SourceFiles/inline_bots/inline_bot_layout_internal.cpp
+++ b/Telegram/SourceFiles/inline_bots/inline_bot_layout_internal.cpp
@@ -134,7 +134,9 @@ void Gif::paint(Painter &p, const QRect &clip, const PaintContext *context) cons
 	bool loaded = document->loaded(), loading = document->loading(), displayLoading = document->displayLoading();
 	if (loaded && !gif() && _gif != Media::Clip::BadReader) {
 		Gif *that = const_cast<Gif*>(this);
-		that->_gif = new Media::Clip::Reader(document->location(), document->data(), func(that, &Gif::clipCallback));
+		that->_gif = new Media::Clip::Reader(document->location(), document->data(), [that](Media::Clip::Notification notification) {
+			that->clipCallback(notification);
+		});
 		if (gif()) _gif->setAutoplay();
 	}
 
@@ -164,9 +166,9 @@ void Gif::paint(Painter &p, const QRect &clip, const PaintContext *context) cons
 	}
 
 	if (radial || (!_gif && !loaded && !loading) || (_gif == Media::Clip::BadReader)) {
-		float64 radialOpacity = (radial && loaded) ? _animation->radial.opacity() : 1;
+		auto radialOpacity = (radial && loaded) ? _animation->radial.opacity() : 1.;
 		if (_animation && _animation->_a_over.animating(context->ms)) {
-			float64 over = _animation->_a_over.current();
+			auto over = _animation->_a_over.current();
 			p.setOpacity((st::msgDateImgBg->c.alphaF() * (1 - over)) + (st::msgDateImgBgOver->c.alphaF() * over));
 			p.fillRect(r, st::black);
 		} else {
@@ -218,7 +220,7 @@ void Gif::clickHandlerActiveChanged(const ClickHandlerPtr &p, bool active) {
 		bool wasactive = (_state & StateFlag::DeleteOver);
 		if (active != wasactive) {
 			auto from = active ? 0. : 1., to = active ? 1. : 0.;
-			START_ANIMATION(_a_deleteOver, func(this, &Gif::update), from, to, st::stickersRowDuration, anim::linear);
+			_a_deleteOver.start([this] { update(); }, from, to, st::stickersRowDuration);
 			if (active) {
 				_state |= StateFlag::DeleteOver;
 			} else {
@@ -232,7 +234,7 @@ void Gif::clickHandlerActiveChanged(const ClickHandlerPtr &p, bool active) {
 			if (!getShownDocument()->loaded()) {
 				ensureAnimation();
 				auto from = active ? 0. : 1., to = active ? 1. : 0.;
-				START_ANIMATION(_animation->_a_over, func(this, &Gif::update), from, to, st::stickersRowDuration, anim::linear);
+				_animation->_a_over.start([this] { update(); }, from, to, st::stickersRowDuration);
 			}
 			if (active) {
 				_state |= StateFlag::Over;
@@ -385,7 +387,7 @@ void Sticker::preload() const {
 void Sticker::paint(Painter &p, const QRect &clip, const PaintContext *context) const {
 	bool loaded = getShownDocument()->loaded();
 
-	float64 over = _a_over.isNull() ? (_active ? 1 : 0) : _a_over.current();
+	auto over = _a_over.current(_active ? 1. : 0.);
 	if (over > 0) {
 		p.setOpacity(over);
 		App::roundRect(p, QRect(QPoint(0, 0), st::stickerPanSize), st::emojiPanHover, StickerHoverCorners);
@@ -414,7 +416,7 @@ void Sticker::clickHandlerActiveChanged(const ClickHandlerPtr &p, bool active) {
 			_active = active;
 
 			auto from = active ? 0. : 1., to = active ? 1. : 0.;
-			START_ANIMATION(_a_over, func(this, &Sticker::update), from, to, st::stickersRowDuration, anim::linear);
+			_a_over.start([this] { update(); }, from, to, st::stickersRowDuration);
 		}
 	}
 	ItemBase::clickHandlerActiveChanged(p, active);
diff --git a/Telegram/SourceFiles/layerwidget.cpp b/Telegram/SourceFiles/layerwidget.cpp
index a5052f877..9c38039f1 100644
--- a/Telegram/SourceFiles/layerwidget.cpp
+++ b/Telegram/SourceFiles/layerwidget.cpp
@@ -638,7 +638,9 @@ QPixmap MediaPreviewWidget::currentImage() const {
 			if (_document->loaded()) {
 				if (!_gif && _gif != Media::Clip::BadReader) {
 					auto that = const_cast<MediaPreviewWidget*>(this);
-					that->_gif = new Media::Clip::Reader(_document->location(), _document->data(), func(that, &MediaPreviewWidget::clipCallback));
+					that->_gif = new Media::Clip::Reader(_document->location(), _document->data(), [this, that](Media::Clip::Notification notification) {
+						that->clipCallback(notification);
+					});
 					if (gif()) _gif->setAutoplay();
 				}
 			}
diff --git a/Telegram/SourceFiles/mainwidget.cpp b/Telegram/SourceFiles/mainwidget.cpp
index 45ea448aa..d96db84ee 100644
--- a/Telegram/SourceFiles/mainwidget.cpp
+++ b/Telegram/SourceFiles/mainwidget.cpp
@@ -4020,7 +4020,7 @@ DataIsLoadedResult allDataLoadedForMessage(const MTPMessage &msg) {
 void MainWidget::feedUpdates(const MTPUpdates &updates, uint64 randomId) {
 	switch (updates.type()) {
 	case mtpc_updates: {
-		const auto &d(updates.c_updates());
+		auto &d = updates.c_updates();
 		if (d.vseq.v) {
 			if (d.vseq.v <= updSeq) return;
 			if (d.vseq.v > updSeq + 1) {
@@ -4037,7 +4037,7 @@ void MainWidget::feedUpdates(const MTPUpdates &updates, uint64 randomId) {
 	} break;
 
 	case mtpc_updatesCombined: {
-		const auto &d(updates.c_updatesCombined());
+		auto &d = updates.c_updatesCombined();
 		if (d.vseq_start.v) {
 			if (d.vseq_start.v <= updSeq) return;
 			if (d.vseq_start.v > updSeq + 1) {
@@ -4054,15 +4054,14 @@ void MainWidget::feedUpdates(const MTPUpdates &updates, uint64 randomId) {
 	} break;
 
 	case mtpc_updateShort: {
-		const auto &d(updates.c_updateShort());
-
+		auto &d = updates.c_updateShort();
 		feedUpdate(d.vupdate);
 
 		updSetState(0, d.vdate.v, updQts, updSeq);
 	} break;
 
 	case mtpc_updateShortMessage: {
-		const auto &d(updates.c_updateShortMessage());
+		auto &d = updates.c_updateShortMessage();
 		if (!App::userLoaded(d.vuser_id.v)
 			|| (d.has_via_bot_id() && !App::userLoaded(d.vvia_bot_id.v))
 			|| (d.has_entities() && !mentionUsersLoaded(d.ventities))
@@ -4076,7 +4075,7 @@ void MainWidget::feedUpdates(const MTPUpdates &updates, uint64 randomId) {
 
 		// update before applying skipped
 		MTPDmessage::Flags flags = mtpCastFlags(d.vflags.v) | MTPDmessage::Flag::f_from_id;
-		HistoryItem *item = App::histories().addNewMessage(MTP_message(MTP_flags(flags), d.vid, d.is_out() ? MTP_int(MTP::authedId()) : d.vuser_id, MTP_peerUser(d.is_out() ? d.vuser_id : MTP_int(MTP::authedId())), d.vfwd_from, d.vvia_bot_id, d.vreply_to_msg_id, d.vdate, d.vmessage, MTP_messageMediaEmpty(), MTPnullMarkup, d.has_entities() ? d.ventities : MTPnullEntities, MTPint(), MTPint()), NewMessageUnread);
+		auto item = App::histories().addNewMessage(MTP_message(MTP_flags(flags), d.vid, d.is_out() ? MTP_int(MTP::authedId()) : d.vuser_id, MTP_peerUser(d.is_out() ? d.vuser_id : MTP_int(MTP::authedId())), d.vfwd_from, d.vvia_bot_id, d.vreply_to_msg_id, d.vdate, d.vmessage, MTP_messageMediaEmpty(), MTPnullMarkup, d.has_entities() ? d.ventities : MTPnullEntities, MTPint(), MTPint()), NewMessageUnread);
 		if (item) {
 			_history->peerMessagesUpdated(item->history()->peer->id);
 		}
@@ -4087,7 +4086,7 @@ void MainWidget::feedUpdates(const MTPUpdates &updates, uint64 randomId) {
 	} break;
 
 	case mtpc_updateShortChatMessage: {
-		const auto &d(updates.c_updateShortChatMessage());
+		auto &d = updates.c_updateShortChatMessage();
 		bool noFrom = !App::userLoaded(d.vfrom_id.v);
 		if (!App::chatLoaded(d.vchat_id.v)
 			|| noFrom
@@ -4104,7 +4103,7 @@ void MainWidget::feedUpdates(const MTPUpdates &updates, uint64 randomId) {
 
 		// update before applying skipped
 		MTPDmessage::Flags flags = mtpCastFlags(d.vflags.v) | MTPDmessage::Flag::f_from_id;
-		HistoryItem *item = App::histories().addNewMessage(MTP_message(MTP_flags(flags), d.vid, d.vfrom_id, MTP_peerChat(d.vchat_id), d.vfwd_from, d.vvia_bot_id, d.vreply_to_msg_id, d.vdate, d.vmessage, MTP_messageMediaEmpty(), MTPnullMarkup, d.has_entities() ? d.ventities : MTPnullEntities, MTPint(), MTPint()), NewMessageUnread);
+		auto item = App::histories().addNewMessage(MTP_message(MTP_flags(flags), d.vid, d.vfrom_id, MTP_peerChat(d.vchat_id), d.vfwd_from, d.vvia_bot_id, d.vreply_to_msg_id, d.vdate, d.vmessage, MTP_messageMediaEmpty(), MTPnullMarkup, d.has_entities() ? d.ventities : MTPnullEntities, MTPint(), MTPint()), NewMessageUnread);
 		if (item) {
 			_history->peerMessagesUpdated(item->history()->peer->id);
 		}
@@ -4115,7 +4114,7 @@ void MainWidget::feedUpdates(const MTPUpdates &updates, uint64 randomId) {
 	} break;
 
 	case mtpc_updateShortSentMessage: {
-		const auto &d(updates.c_updateShortSentMessage());
+		auto &d = updates.c_updateShortSentMessage();
 		if (randomId) {
 			PeerId peerId = 0;
 			QString text;
@@ -4125,7 +4124,7 @@ void MainWidget::feedUpdates(const MTPUpdates &updates, uint64 randomId) {
 			if (peerId) {
 				if (auto item = App::histItemById(peerToChannel(peerId), d.vid.v)) {
 					if (d.has_entities() && !mentionUsersLoaded(d.ventities)) {
-						api()->requestMessageData(item->history()->peer->asChannel(), item->id, nullptr);
+						api()->requestMessageData(item->history()->peer->asChannel(), item->id, ApiWrap::RequestMessageDataCallback());
 					}
 					auto entities = d.has_entities() ? entitiesFromMTP(d.ventities.c_vector().v) : EntitiesInText();
 					item->setText({ text, entities });
diff --git a/Telegram/SourceFiles/media/media_clip_reader.cpp b/Telegram/SourceFiles/media/media_clip_reader.cpp
index 2ed2aa0e0..792cefaa4 100644
--- a/Telegram/SourceFiles/media/media_clip_reader.cpp
+++ b/Telegram/SourceFiles/media/media_clip_reader.cpp
@@ -180,8 +180,8 @@ void Reader::moveToNextWrite() const {
 
 void Reader::callback(Reader *reader, int32 threadIndex, Notification notification) {
 	// check if reader is not deleted already
-	if (managers.size() > threadIndex && managers.at(threadIndex)->carries(reader)) {
-		reader->_callback.call(notification);
+	if (managers.size() > threadIndex && managers.at(threadIndex)->carries(reader) && reader->_callback) {
+		reader->_callback(notification);
 	}
 }
 
diff --git a/Telegram/SourceFiles/media/media_clip_reader.h b/Telegram/SourceFiles/media/media_clip_reader.h
index 90dd5e3dd..220632c55 100644
--- a/Telegram/SourceFiles/media/media_clip_reader.h
+++ b/Telegram/SourceFiles/media/media_clip_reader.h
@@ -52,7 +52,7 @@ enum ReaderSteps {
 class ReaderPrivate;
 class Reader {
 public:
-	using Callback = Function<void, Notification>;
+	using Callback = base::lambda_unique<void(Notification)>;
 	enum class Mode {
 		Gif,
 		Video,
diff --git a/Telegram/SourceFiles/media/view/media_clip_controller.cpp b/Telegram/SourceFiles/media/view/media_clip_controller.cpp
index 796aee8cc..3e76932e1 100644
--- a/Telegram/SourceFiles/media/view/media_clip_controller.cpp
+++ b/Telegram/SourceFiles/media/view/media_clip_controller.cpp
@@ -41,8 +41,8 @@ Controller::Controller(QWidget *parent) : TWidget(parent)
 , _toPlayLeft(this, st::mediaviewPlayProgressLabel)
 , _fadeAnimation(std_::make_unique<Ui::FadeAnimation>(this)) {
 	_fadeAnimation->show();
-	_fadeAnimation->setFinishedCallback(func(this, &Controller::fadeFinished));
-	_fadeAnimation->setUpdatedCallback(func(this, &Controller::fadeUpdated));
+	_fadeAnimation->setFinishedCallback([this] { fadeFinished(); });
+	_fadeAnimation->setUpdatedCallback([this](float64 opacity) { fadeUpdated(opacity); });
 
 	_volumeController->setVolume(Global::VideoVolume());
 
diff --git a/Telegram/SourceFiles/media/view/media_clip_playback.cpp b/Telegram/SourceFiles/media/view/media_clip_playback.cpp
index 6dfbaed15..b5b33e423 100644
--- a/Telegram/SourceFiles/media/view/media_clip_playback.cpp
+++ b/Telegram/SourceFiles/media/view/media_clip_playback.cpp
@@ -156,7 +156,7 @@ void Playback::setOver(bool over) {
 
 	_over = over;
 	auto from = _over ? 0. : 1., to = _over ? 1. : 0.;
-	START_ANIMATION(_a_over, func(this, &Playback::updateCallback), from, to, st::mediaviewOverDuration, anim::linear);
+	_a_over.start([this] { update(); }, from, to, st::mediaviewOverDuration);
 }
 
 } // namespace Clip
diff --git a/Telegram/SourceFiles/media/view/media_clip_playback.h b/Telegram/SourceFiles/media/view/media_clip_playback.h
index 190358d78..029c4503a 100644
--- a/Telegram/SourceFiles/media/view/media_clip_playback.h
+++ b/Telegram/SourceFiles/media/view/media_clip_playback.h
@@ -48,9 +48,6 @@ protected:
 
 private:
 	void step_progress(float64 ms, bool timer);
-	void updateCallback() {
-		update();
-	}
 	void setOver(bool over);
 
 	bool _over = false;
diff --git a/Telegram/SourceFiles/media/view/media_clip_volume_controller.cpp b/Telegram/SourceFiles/media/view/media_clip_volume_controller.cpp
index 8ffed03f2..c1b83746f 100644
--- a/Telegram/SourceFiles/media/view/media_clip_volume_controller.cpp
+++ b/Telegram/SourceFiles/media/view/media_clip_volume_controller.cpp
@@ -100,7 +100,7 @@ void VolumeController::setOver(bool over) {
 
 	_over = over;
 	auto from = _over ? 0. : 1., to = _over ? 1. : 0.;
-	START_ANIMATION(_a_over, func(this, &VolumeController::updateCallback), from, to, st::mediaviewOverDuration, anim::linear);
+	_a_over.start([this] { update(); }, from, to, st::mediaviewOverDuration);
 }
 
 } // namespace Clip
diff --git a/Telegram/SourceFiles/media/view/media_clip_volume_controller.h b/Telegram/SourceFiles/media/view/media_clip_volume_controller.h
index cf062ce09..69389eeab 100644
--- a/Telegram/SourceFiles/media/view/media_clip_volume_controller.h
+++ b/Telegram/SourceFiles/media/view/media_clip_volume_controller.h
@@ -43,9 +43,6 @@ protected:
 	void leaveEvent(QEvent *e) override;
 
 private:
-	void updateCallback() {
-		update();
-	}
 	void setOver(bool over);
 	void changeVolume(float64 newVolume);
 
diff --git a/Telegram/SourceFiles/mediaview.cpp b/Telegram/SourceFiles/mediaview.cpp
index 77eb491d7..8e4ea3e3c 100644
--- a/Telegram/SourceFiles/mediaview.cpp
+++ b/Telegram/SourceFiles/mediaview.cpp
@@ -1368,7 +1368,9 @@ void MediaView::createClipReader() {
 		_current = _doc->thumb->pixNoCache(_doc->thumb->width(), _doc->thumb->height(), ImagePixSmooth | ImagePixBlurred, st::mvDocIconSize, st::mvDocIconSize);
 	}
 	auto mode = _doc->isVideo() ? Media::Clip::Reader::Mode::Video : Media::Clip::Reader::Mode::Gif;
-	_gif = std_::make_unique<Media::Clip::Reader>(_doc->location(), _doc->data(), func(this, &MediaView::clipCallback), mode);
+	_gif = std_::make_unique<Media::Clip::Reader>(_doc->location(), _doc->data(), [this](Media::Clip::Notification notification) {
+		clipCallback(notification);
+	}, mode);
 
 	// Correct values will be set when gif gets inited.
 	_videoPaused = _videoIsSilent = _videoStopped = false;
@@ -1439,7 +1441,9 @@ void MediaView::restartVideoAtSeekPosition(int64 positionMs) {
 	if (_current.isNull()) {
 		_current = _gif->current(_gif->width(), _gif->height(), _gif->width(), _gif->height(), getms());
 	}
-	_gif = std_::make_unique<Media::Clip::Reader>(_doc->location(), _doc->data(), func(this, &MediaView::clipCallback), Media::Clip::Reader::Mode::Video, positionMs);
+	_gif = std_::make_unique<Media::Clip::Reader>(_doc->location(), _doc->data(), [this](Media::Clip::Notification notification) {
+		clipCallback(notification);
+	}, Media::Clip::Reader::Mode::Video, positionMs);
 
 	// Correct values will be set when gif gets inited.
 	_videoPaused = _videoIsSilent = _videoStopped = false;
diff --git a/Telegram/SourceFiles/mtproto/file_download.h b/Telegram/SourceFiles/mtproto/file_download.h
index 94b65fb2b..0d883504b 100644
--- a/Telegram/SourceFiles/mtproto/file_download.h
+++ b/Telegram/SourceFiles/mtproto/file_download.h
@@ -396,9 +396,10 @@ void reinitWebLoadManager();
 void stopWebLoadManager();
 
 namespace FileDownload {
+
 namespace internal {
 
-using ImageLoadedHandler = Function<void>;
+using ImageLoadedHandler = base::lambda_unique<void()>;
 Notify::ConnectionId plainRegisterImageLoadedObserver(ImageLoadedHandler &&handler);
 
 void notifyImageLoaded();
@@ -407,7 +408,9 @@ void notifyImageLoaded();
 
 template <typename ObserverType>
 void registerImageLoadedObserver(ObserverType *observer, void (ObserverType::*handler)()) {
-	auto connection = internal::plainRegisterImageLoadedObserver(func(observer, handler));
+	auto connection = internal::plainRegisterImageLoadedObserver([observer, handler]() {
+		(observer->*handler)();
+	});
 	Notify::observerRegistered(observer, connection);
 }
 
diff --git a/Telegram/SourceFiles/observer_peer.h b/Telegram/SourceFiles/observer_peer.h
index fe0e26cbc..aee59e5c3 100644
--- a/Telegram/SourceFiles/observer_peer.h
+++ b/Telegram/SourceFiles/observer_peer.h
@@ -91,14 +91,16 @@ void peerUpdatedSendDelayed();
 
 namespace internal {
 
-using PeerUpdateHandler = Function<void, const PeerUpdate&>;
+using PeerUpdateHandler = base::lambda_unique<void(const PeerUpdate&)>;
 ConnectionId plainRegisterPeerObserver(PeerUpdate::Flags events, PeerUpdateHandler &&handler);
 
 } // namespace internal
 
 template <typename ObserverType>
 void registerPeerObserver(PeerUpdate::Flags events, ObserverType *observer, void (ObserverType::*handler)(const PeerUpdate &)) {
-	auto connection = internal::plainRegisterPeerObserver(events, func(observer, handler));
+	auto connection = internal::plainRegisterPeerObserver(events, [observer, handler](const PeerUpdate &update) {
+		(observer->*handler)(update);
+	});
 	observerRegistered(observer, connection);
 }
 
diff --git a/Telegram/SourceFiles/profile/profile_cover.cpp b/Telegram/SourceFiles/profile/profile_cover.cpp
index 056b2f07c..16e2cb6cc 100644
--- a/Telegram/SourceFiles/profile/profile_cover.cpp
+++ b/Telegram/SourceFiles/profile/profile_cover.cpp
@@ -285,7 +285,7 @@ void CoverWidget::dragEnterEvent(QDragEnterEvent *e) {
 
 void CoverWidget::dragLeaveEvent(QDragLeaveEvent *e) {
 	if (_dropArea && !_dropArea->hiding()) {
-		_dropArea->hideAnimated(func(this, &CoverWidget::dropAreaHidden));
+		_dropArea->hideAnimated([this](CoverDropArea *area) { dropAreaHidden(area); });
 	}
 }
 
@@ -306,7 +306,7 @@ void CoverWidget::dropEvent(QDropEvent *e) {
 	}
 
 	if (!_dropArea->hiding()) {
-		_dropArea->hideAnimated(func(this, &CoverWidget::dropAreaHidden));
+		_dropArea->hideAnimated([this](CoverDropArea *area) { dropAreaHidden(area); });
 	}
 	e->acceptProposedAction();
 
diff --git a/Telegram/SourceFiles/profile/profile_cover_drop_area.cpp b/Telegram/SourceFiles/profile/profile_cover_drop_area.cpp
index e3370f66d..e23e8fc74 100644
--- a/Telegram/SourceFiles/profile/profile_cover_drop_area.cpp
+++ b/Telegram/SourceFiles/profile/profile_cover_drop_area.cpp
@@ -57,7 +57,9 @@ void CoverDropArea::paintEvent(QPaintEvent *e) {
 		_cache = QPixmap();
 		if (_hiding) {
 			hide();
-			_hideFinishCallback.call(this);
+			if (_hideFinishCallback) {
+				_hideFinishCallback(this);
+			}
 			return;
 		}
 	}
@@ -93,7 +95,7 @@ void CoverDropArea::setupAnimation() {
 		_cache = myGrab(this);
 	}
 	auto from = _hiding ? 1. : 0., to = _hiding ? 0. : 1.;
-	START_ANIMATION(_a_appearance, func(this, &CoverDropArea::refreshCallback), from, to, st::profileDropAreaDuration, anim::linear);
+	_a_appearance.start([this]() { update(); }, from, to, st::profileDropAreaDuration);
 }
 
 } // namespace Profile
diff --git a/Telegram/SourceFiles/profile/profile_cover_drop_area.h b/Telegram/SourceFiles/profile/profile_cover_drop_area.h
index 871523ff8..063e223ea 100644
--- a/Telegram/SourceFiles/profile/profile_cover_drop_area.h
+++ b/Telegram/SourceFiles/profile/profile_cover_drop_area.h
@@ -28,7 +28,7 @@ public:
 
 	void showAnimated();
 
-	using HideFinishCallback = Function<void, CoverDropArea*>;
+	using HideFinishCallback = base::lambda_unique<void(CoverDropArea*)>;
 	void hideAnimated(HideFinishCallback &&callback);
 
 	bool hiding() const {
@@ -39,9 +39,6 @@ protected:
 	void paintEvent(QPaintEvent *e) override;
 
 private:
-	void refreshCallback() {
-		update();
-	}
 	void setupAnimation();
 
 	QString _title, _subtitle;
diff --git a/Telegram/SourceFiles/profile/profile_info_widget.cpp b/Telegram/SourceFiles/profile/profile_info_widget.cpp
index bbb62d9e2..032f6cd6f 100644
--- a/Telegram/SourceFiles/profile/profile_info_widget.cpp
+++ b/Telegram/SourceFiles/profile/profile_info_widget.cpp
@@ -149,15 +149,13 @@ void InfoWidget::refreshAbout() {
 		textParseEntities(aboutText, TextParseLinks | TextParseMentions | TextParseHashtags | TextParseBotCommands, &aboutEntities);
 		_about->setMarkedText({ aboutText, aboutEntities });
 		_about->setSelectable(true);
-		_about->setClickHandlerHook(func(this, &InfoWidget::aboutClickHandlerHook));
+		_about->setClickHandlerHook([this](const ClickHandlerPtr &handler, Qt::MouseButton button) {
+			BotCommandClickHandler::setPeerForCommand(peer());
+			return true;
+		});
 	}
 }
 
-bool InfoWidget::aboutClickHandlerHook(const ClickHandlerPtr &handler, Qt::MouseButton button) {
-	BotCommandClickHandler::setPeerForCommand(peer());
-	return true;
-}
-
 void InfoWidget::refreshMobileNumber() {
 	TextWithEntities phoneText;
 	if (auto user = peer()->asUser()) {
diff --git a/Telegram/SourceFiles/profile/profile_info_widget.h b/Telegram/SourceFiles/profile/profile_info_widget.h
index 16be5604b..37618ab77 100644
--- a/Telegram/SourceFiles/profile/profile_info_widget.h
+++ b/Telegram/SourceFiles/profile/profile_info_widget.h
@@ -51,8 +51,6 @@ private:
 	void refreshChannelLink();
 	void refreshVisibility();
 
-	bool aboutClickHandlerHook(const ClickHandlerPtr &handler, Qt::MouseButton button);
-
 	// labelWidget may be nullptr.
 	void setLabeledText(ChildWidget<FlatLabel> *labelWidget, const QString &label,
 		ChildWidget<FlatLabel> *textWidget, const TextWithEntities &textWithEntities, const QString &copyText);
diff --git a/Telegram/SourceFiles/profile/profile_invite_link_widget.cpp b/Telegram/SourceFiles/profile/profile_invite_link_widget.cpp
index f0a524578..294d4626b 100644
--- a/Telegram/SourceFiles/profile/profile_invite_link_widget.cpp
+++ b/Telegram/SourceFiles/profile/profile_invite_link_widget.cpp
@@ -99,19 +99,17 @@ void InviteLinkWidget::refreshLink() {
 		_link->setMarkedText(linkData);
 		_link->setSelectable(true);
 		_link->setContextCopyText(QString());
-		_link->setClickHandlerHook(func(this, &InviteLinkWidget::clickHandlerHook));
-	}
-}
+		_link->setClickHandlerHook([this](const ClickHandlerPtr &handler, Qt::MouseButton button) {
+			auto link = getInviteLink();
+			if (link.isEmpty()) {
+				return true;
+			}
 
-bool InviteLinkWidget::clickHandlerHook(const ClickHandlerPtr &handler, Qt::MouseButton button) {
-	auto link = getInviteLink();
-	if (link.isEmpty()) {
-		return true;
+			QApplication::clipboard()->setText(link);
+			Ui::showLayer(new InformBox(lang(lng_group_invite_copied)));
+			return false;
+		});
 	}
-
-	QApplication::clipboard()->setText(link);
-	Ui::showLayer(new InformBox(lang(lng_group_invite_copied)));
-	return false;
 }
 
 } // namespace Profile
diff --git a/Telegram/SourceFiles/profile/profile_invite_link_widget.h b/Telegram/SourceFiles/profile/profile_invite_link_widget.h
index 65ef20b71..e01c043ff 100644
--- a/Telegram/SourceFiles/profile/profile_invite_link_widget.h
+++ b/Telegram/SourceFiles/profile/profile_invite_link_widget.h
@@ -46,8 +46,6 @@ private:
 	void refreshLink();
 	void refreshVisibility();
 
-	bool clickHandlerHook(const ClickHandlerPtr &handler, Qt::MouseButton button);
-
 	ChildWidget<FlatLabel> _link = { nullptr };
 
 };
diff --git a/Telegram/SourceFiles/profile/profile_members_widget.cpp b/Telegram/SourceFiles/profile/profile_members_widget.cpp
index 472c1b64d..78db1d3c9 100644
--- a/Telegram/SourceFiles/profile/profile_members_widget.cpp
+++ b/Telegram/SourceFiles/profile/profile_members_widget.cpp
@@ -315,17 +315,15 @@ void MembersWidget::refreshLimitReached() {
 		QString link = textRichPrepare(lang(lng_profile_migrate_learn_more));
 		QString text = qsl("%1%2%3\n%4 [a href=\"https://telegram.org/blog/supergroups5k\"]%5[/a]").arg(textcmdStartSemibold()).arg(title).arg(textcmdStopSemibold()).arg(body).arg(link);
 		_limitReachedInfo->setRichText(text);
-		_limitReachedInfo->setClickHandlerHook(func(this, &MembersWidget::limitReachedHook));
+		_limitReachedInfo->setClickHandlerHook([this](const ClickHandlerPtr &handler, Qt::MouseButton button) {
+			Ui::showLayer(new ConvertToSupergroupBox(peer()->asChat()));
+			return false;
+		});
 	} else if (!limitReachedShown && _limitReachedInfo) {
 		_limitReachedInfo.destroy();
 	}
 }
 
-bool MembersWidget::limitReachedHook(const ClickHandlerPtr &handler, Qt::MouseButton button) {
-	Ui::showLayer(new ConvertToSupergroupBox(peer()->asChat()));
-	return false;
-}
-
 void MembersWidget::checkSelfAdmin(ChatData *chat) {
 	if (chat->participants.isEmpty()) return;
 
diff --git a/Telegram/SourceFiles/profile/profile_userpic_button.cpp b/Telegram/SourceFiles/profile/profile_userpic_button.cpp
index 048777f1b..e1b92dedb 100644
--- a/Telegram/SourceFiles/profile/profile_userpic_button.cpp
+++ b/Telegram/SourceFiles/profile/profile_userpic_button.cpp
@@ -45,7 +45,7 @@ void UserpicButton::showFinished() {
 		_notShownYet = false;
 		if (!_waiting) {
 			_a_appearance.finish();
-			START_ANIMATION(_a_appearance, func(this, &UserpicButton::refreshCallback), 0, 1, st::profilePhotoDuration, anim::linear);
+			_a_appearance.start([this] { update(); }, 0, 1, st::profilePhotoDuration);
 		}
 	}
 }
@@ -100,7 +100,7 @@ void UserpicButton::startNewPhotoShowing() {
 	}
 
 	_a_appearance.finish();
-	START_ANIMATION(_a_appearance, func(this, &UserpicButton::refreshCallback), 0, 1, st::profilePhotoDuration, anim::linear);
+	_a_appearance.start([this] { update(); }, 0, 1, st::profilePhotoDuration);
 	update();
 }
 
diff --git a/Telegram/SourceFiles/profile/profile_userpic_button.h b/Telegram/SourceFiles/profile/profile_userpic_button.h
index 8dc63b1f6..cd75d80a4 100644
--- a/Telegram/SourceFiles/profile/profile_userpic_button.h
+++ b/Telegram/SourceFiles/profile/profile_userpic_button.h
@@ -43,10 +43,6 @@ private:
 	void notifyPeerUpdated(const Notify::PeerUpdate &update);
 	void notifyImageLoaded();
 
-	void refreshCallback() {
-		update();
-	}
-
 	void processPeerPhoto();
 	void processNewPeerPhoto();
 	void startNewPhotoShowing();
diff --git a/Telegram/SourceFiles/settings/settings_cover.cpp b/Telegram/SourceFiles/settings/settings_cover.cpp
index 11047c067..50d57b299 100644
--- a/Telegram/SourceFiles/settings/settings_cover.cpp
+++ b/Telegram/SourceFiles/settings/settings_cover.cpp
@@ -217,7 +217,7 @@ void CoverWidget::dragEnterEvent(QDragEnterEvent *e) {
 
 void CoverWidget::dragLeaveEvent(QDragLeaveEvent *e) {
 	if (_dropArea && !_dropArea->hiding()) {
-		_dropArea->hideAnimated(func(this, &CoverWidget::dropAreaHidden));
+		_dropArea->hideAnimated([this](Profile::CoverDropArea *area) { dropAreaHidden(area); });
 	}
 }
 
@@ -228,7 +228,7 @@ void CoverWidget::dropEvent(QDropEvent *e) {
 	if (mimeData->hasImage()) {
 		img = qvariant_cast<QImage>(mimeData->imageData());
 	} else {
-		const auto &urls = mimeData->urls();
+		auto &urls = mimeData->urls();
 		if (urls.size() == 1) {
 			auto &url = urls.at(0);
 			if (url.isLocalFile()) {
@@ -238,7 +238,7 @@ void CoverWidget::dropEvent(QDropEvent *e) {
 	}
 
 	if (!_dropArea->hiding()) {
-		_dropArea->hideAnimated(func(this, &CoverWidget::dropAreaHidden));
+		_dropArea->hideAnimated([this](Profile::CoverDropArea *area) { dropAreaHidden(area); });
 	}
 	e->acceptProposedAction();
 
diff --git a/Telegram/SourceFiles/settings/settings_info_widget.cpp b/Telegram/SourceFiles/settings/settings_info_widget.cpp
index 88acf95b4..28219a858 100644
--- a/Telegram/SourceFiles/settings/settings_info_widget.cpp
+++ b/Telegram/SourceFiles/settings/settings_info_widget.cpp
@@ -81,7 +81,10 @@ void InfoWidget::refreshUsername() {
 	usernameText.entities.push_back(EntityInText(EntityInTextCustomUrl, 0, usernameText.text.size(), qsl("https://telegram.me/") + self()->username));
 	setLabeledText(_username, lang(lng_profile_username), usernameText, TextWithEntities(), copyText);
 	if (auto text = _username->entity()->textLabel()) {
-		text->setClickHandlerHook(func(this, &InfoWidget::usernameClickHandlerHook));
+		text->setClickHandlerHook([](const ClickHandlerPtr &handler, Qt::MouseButton button) {
+			Ui::showLayer(new UsernameBox());
+			return false;
+		});
 	}
 }
 
@@ -96,19 +99,20 @@ void InfoWidget::refreshLink() {
 	}
 	setLabeledText(_link, lang(lng_profile_link), linkText, linkTextShort, QString());
 	if (auto text = _link->entity()->textLabel()) {
-		text->setClickHandlerHook(func(this, &InfoWidget::usernameClickHandlerHook));
+		text->setClickHandlerHook([](const ClickHandlerPtr &handler, Qt::MouseButton button) {
+			Ui::showLayer(new UsernameBox());
+			return false;
+		});
 	}
 	if (auto shortText = _link->entity()->shortTextLabel()) {
 		shortText->setExpandLinksMode(ExpandLinksUrlOnly);
-		shortText->setClickHandlerHook(func(this, &InfoWidget::usernameClickHandlerHook));
+		shortText->setClickHandlerHook([](const ClickHandlerPtr &handler, Qt::MouseButton button) {
+			Ui::showLayer(new UsernameBox());
+			return false;
+		});
 	}
 }
 
-bool InfoWidget::usernameClickHandlerHook(const ClickHandlerPtr &handler, Qt::MouseButton button) {
-	Ui::showLayer(new UsernameBox());
-	return false;
-}
-
 void InfoWidget::setLabeledText(ChildWidget<LabeledWrap> &row, const QString &label, const TextWithEntities &textWithEntities, const TextWithEntities &shortTextWithEntities, const QString &copyText) {
 	if (textWithEntities.text.isEmpty()) {
 		row->slideUp();
diff --git a/Telegram/SourceFiles/settings/settings_info_widget.h b/Telegram/SourceFiles/settings/settings_info_widget.h
index 6ffdc791d..52a6f2b05 100644
--- a/Telegram/SourceFiles/settings/settings_info_widget.h
+++ b/Telegram/SourceFiles/settings/settings_info_widget.h
@@ -38,8 +38,6 @@ private:
 	// Observed notifications.
 	void notifyPeerUpdated(const Notify::PeerUpdate &update);
 
-	bool usernameClickHandlerHook(const ClickHandlerPtr &handler, Qt::MouseButton button);
-
 	void createControls();
 	void refreshControls();
 	void refreshMobileNumber();
diff --git a/Telegram/SourceFiles/ui/animation.cpp b/Telegram/SourceFiles/ui/animation.cpp
index 3f6d97a37..83e3bc729 100644
--- a/Telegram/SourceFiles/ui/animation.cpp
+++ b/Telegram/SourceFiles/ui/animation.cpp
@@ -120,7 +120,7 @@ AnimationManager::AnimationManager() : _timer(this), _iterating(false) {
 
 void AnimationManager::start(Animation *obj) {
 	if (_iterating) {
-		_starting.insert(obj, NullType());
+		_starting.insert(obj);
 		if (!_stopping.isEmpty()) {
 			_stopping.remove(obj);
 		}
@@ -128,21 +128,21 @@ void AnimationManager::start(Animation *obj) {
 		if (_objects.isEmpty()) {
 			_timer.start(AnimationTimerDelta);
 		}
-		_objects.insert(obj, NullType());
+		_objects.insert(obj);
 	}
 }
 
 void AnimationManager::stop(Animation *obj) {
 	if (_iterating) {
-		_stopping.insert(obj, NullType());
+		_stopping.insert(obj);
 		if (!_starting.isEmpty()) {
 			_starting.remove(obj);
 		}
 	} else {
-		AnimatingObjects::iterator i = _objects.find(obj);
+		auto i = _objects.find(obj);
 		if (i != _objects.cend()) {
 			_objects.erase(i);
-			if (_objects.isEmpty()) {
+			if (_objects.empty()) {
 				_timer.stop();
 			}
 		}
@@ -152,26 +152,26 @@ void AnimationManager::stop(Animation *obj) {
 void AnimationManager::timeout() {
 	_iterating = true;
 	uint64 ms = getms();
-	for (AnimatingObjects::const_iterator i = _objects.begin(), e = _objects.end(); i != e; ++i) {
-		if (!_stopping.contains(i.key())) {
-			i.key()->step(ms, true);
+	for_const (auto object, _objects) {
+		if (!_stopping.contains(object)) {
+			object->step(ms, true);
 		}
 	}
 	_iterating = false;
 
 	if (!_starting.isEmpty()) {
-		for (AnimatingObjects::iterator i = _starting.begin(), e = _starting.end(); i != e; ++i) {
-			_objects.insert(i.key(), NullType());
+		for_const (auto object, _starting) {
+			_objects.insert(object);
 		}
 		_starting.clear();
 	}
 	if (!_stopping.isEmpty()) {
-		for (AnimatingObjects::iterator i = _stopping.begin(), e = _stopping.end(); i != e; ++i) {
-			_objects.remove(i.key());
+		for_const (auto object, _stopping) {
+			_objects.remove(object);
 		}
 		_stopping.clear();
 	}
-	if (!_objects.size()) {
+	if (_objects.empty()) {
 		_timer.stop();
 	}
 }
diff --git a/Telegram/SourceFiles/ui/animation.h b/Telegram/SourceFiles/ui/animation.h
index 8fc5201cf..4130012c6 100644
--- a/Telegram/SourceFiles/ui/animation.h
+++ b/Telegram/SourceFiles/ui/animation.h
@@ -21,6 +21,7 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 #pragma once
 
 #include "core/basic_types.h"
+#include "core/lambda_wrap.h"
 #include <QtCore/QTimer>
 #include <QtGui/QColor>
 
@@ -57,6 +58,7 @@ namespace anim {
 
 	class fvalue { // float animated value
 	public:
+		using ValueType = float64;
 
 		fvalue() {
 		}
@@ -88,15 +90,14 @@ namespace anim {
 			_delta = 0;
 		}
 
-		typedef float64 Type;
-
 	private:
-
 		float64 _cur, _from, _delta;
+
 	};
 
 	class ivalue { // int animated value
 	public:
+		using ValueType = int32;
 
 		ivalue() {
 		}
@@ -128,16 +129,15 @@ namespace anim {
 			_delta = 0;
 		}
 
-		typedef int32 Type;
-
 	private:
-
 		int32 _cur;
 		float64 _from, _delta;
+
 	};
 
 	class cvalue { // QColor animated value
 	public:
+		using ValueType = QColor;
 
 		cvalue() {
 		}
@@ -199,12 +199,10 @@ namespace anim {
 			_delta_r = _delta_g = _delta_b = _delta_a = 0;
 		}
 
-		typedef QColor Type;
-
 	private:
-
 		QColor _cur;
 		float64 _from_r, _from_g, _from_b, _from_a, _delta_r, _delta_g, _delta_b, _delta_a;
+
 	};
 
 	void startManager();
@@ -380,105 +378,81 @@ AnimationCallbacks animation(Param param, Type *obj, typename AnimationCallbacks
 template <typename AnimType>
 class SimpleAnimation {
 public:
-	using Callback = Function<void>;
+	using ValueType = typename AnimType::ValueType;
+	using Callback = base::lambda_unique<void()>;
 
-	SimpleAnimation() {
+	bool animating() const {
+		if (_data) {
+			if (_data->a_animation.animating()) {
+				return true;
+			}
+			_data.reset();
+		}
+		return false;
 	}
-
 	bool animating(uint64 ms) {
-		if (_data && _data->_a.animating()) {
-			_data->_a.step(ms);
-			return _data && _data->_a.animating();
+		if (animating()) {
+			_data->a_animation.step(ms);
+			return animating();
 		}
 		return false;
 	}
 
-	bool isNull() const {
-		return !_data;
+	ValueType current() const {
+		t_assert(_data != nullptr);
+		return _data->value.current();
 	}
-
-	typename AnimType::Type current() {
-		return _data ? _data->a.current() : typename AnimType::Type();
+	ValueType current(const ValueType &def) const {
+		return _data ? current() : def;
 	}
-
-	typename AnimType::Type current(const typename AnimType::Type &def) {
-		return _data ? _data->a.current() : def;
-	}
-
-	typename AnimType::Type current(uint64 ms, const typename AnimType::Type &def) {
+	ValueType current(uint64 ms, const ValueType &def) {
 		return animating(ms) ? current() : def;
 	}
 
-	void setup(const typename AnimType::Type &from, Callback &&update) {
+	template <typename Lambda>
+	void start(Lambda &&updateCallback, const ValueType &from, const ValueType &to, float64 duration, anim::transition transition = anim::linear) {
 		if (!_data) {
-			_data = new Data(from, std_::move(update), animation(this, &SimpleAnimation<AnimType>::step));
-		} else {
-			_data->a = AnimType(from, from);
-		}
-	}
-
-	void start(const typename AnimType::Type &to, float64 duration, anim::transition transition = anim::linear) {
-		if (_data) {
-			_data->a.start(to);
-			_data->_a.start();
-			_data->duration = duration;
-			_data->transition = transition;
+			_data = std_::make_unique<Data>(from, std_::move(updateCallback));
 		}
+		_data->value.start(to);
+		_data->duration = duration;
+		_data->transition = transition;
+		_data->a_animation.start();
 	}
 
 	void finish() {
-		if (isNull()) {
-			return;
+		if (_data) {
+			_data->value.finish();
+			_data->a_animation.stop();
+			_data.reset();
 		}
-
-		_data->a.finish();
-		_data->_a.stop();
-		delete _data;
-		_data = nullptr;
-	}
-
-	~SimpleAnimation() {
-		deleteAndMark(_data);
 	}
 
 private:
 	struct Data {
-		Data(const typename AnimType::Type &from, Callback &&update, AnimationCallbacks &&acb)
-			: a(from, from)
-			, _a(std_::move(acb))
-			, update(std_::move(update))
-			, duration(0)
-			, transition(anim::linear) {
+		Data(const ValueType &from, Callback &&updateCallback)
+			: value(from, from)
+			, a_animation(animation(this, &Data::step))
+			, updateCallback(std_::move(updateCallback)) {
 		}
-		AnimType a;
-		Animation _a;
-		Callback update;
-		float64 duration;
-		anim::transition transition;
+		void step(float64 ms, bool timer) {
+			auto dt = (ms >= duration) ? 1. : (ms / duration);
+			if (dt >= 1) {
+				value.finish();
+				a_animation.stop();
+			} else {
+				value.update(dt, transition);
+			}
+			updateCallback();
+		}
+
+		AnimType value;
+		Animation a_animation;
+		Callback updateCallback;
+		float64 duration = 0.;
+		anim::transition transition = anim::linear;
 	};
-	Data *_data = nullptr;
-
-	void step(float64 ms, bool timer) {
-		float64 dt = (ms >= _data->duration) ? 1 : (ms / _data->duration);
-		if (dt >= 1) {
-			_data->a.finish();
-			_data->_a.stop();
-		} else {
-			_data->a.update(dt, _data->transition);
-		}
-
-		Callback callbackCache, *toCall = &_data->update;
-		if (!_data->_a.animating()) {
-			callbackCache = std_::move(_data->update);
-			toCall = &callbackCache;
-
-			delete _data;
-			_data = nullptr;
-		}
-		if (timer) {
-			toCall->call();
-		}
-	}
+	mutable std_::unique_ptr<Data> _data;
 
 };
 
@@ -486,18 +460,8 @@ using FloatAnimation = SimpleAnimation<anim::fvalue>;
 using IntAnimation = SimpleAnimation<anim::ivalue>;
 using ColorAnimation = SimpleAnimation<anim::cvalue>;
 
-// Macro allows us to lazily create updateCallback.
-#define ENSURE_ANIMATION(animation, updateCallback, from) \
-if ((animation).isNull()) { \
-	(animation).setup((from), (updateCallback)); \
-}
-
-#define START_ANIMATION(animation, updateCallback, from, to, duration, transition) \
-ENSURE_ANIMATION(animation, updateCallback, from); \
-(animation).start((to), (duration), (transition))
-
 class AnimationManager : public QObject {
-Q_OBJECT
+	Q_OBJECT
 
 public:
 	AnimationManager();
@@ -511,7 +475,7 @@ public slots:
 	void clipCallback(Media::Clip::Reader *reader, qint32 threadIndex, qint32 notification);
 
 private:
-	typedef QMap<Animation*, NullType> AnimatingObjects;
+	using AnimatingObjects = OrderedSet<Animation*>;
 	AnimatingObjects _objects, _starting, _stopping;
 	QTimer _timer;
 	bool _iterating;
diff --git a/Telegram/SourceFiles/ui/buttons/history_down_button.cpp b/Telegram/SourceFiles/ui/buttons/history_down_button.cpp
index 2b1fd86e9..773742426 100644
--- a/Telegram/SourceFiles/ui/buttons/history_down_button.cpp
+++ b/Telegram/SourceFiles/ui/buttons/history_down_button.cpp
@@ -118,7 +118,7 @@ void HistoryDownButton::hideAnimated() {
 void HistoryDownButton::toggleAnimated() {
 	_shown = !_shown;
 	float64 from = _shown ? 0. : 1., to = _shown ? 1. : 0.;
-	START_ANIMATION(_a_show, func(this, &HistoryDownButton::repaintCallback), from, to, st::btnAttachEmoji.duration, anim::linear);
+	_a_show.start([this] { update(); }, from, to, st::btnAttachEmoji.duration);
 }
 
 void HistoryDownButton::finishAnimation() {
diff --git a/Telegram/SourceFiles/ui/buttons/history_down_button.h b/Telegram/SourceFiles/ui/buttons/history_down_button.h
index 43dbd098c..8030a905e 100644
--- a/Telegram/SourceFiles/ui/buttons/history_down_button.h
+++ b/Telegram/SourceFiles/ui/buttons/history_down_button.h
@@ -47,9 +47,6 @@ protected:
 
 private:
 	void toggleAnimated();
-	void repaintCallback() {
-		update();
-	}
 	void step_arrowOver(float64 ms, bool timer);
 
 	QPixmap _cache;
diff --git a/Telegram/SourceFiles/ui/buttons/icon_button.cpp b/Telegram/SourceFiles/ui/buttons/icon_button.cpp
index 43498c7cc..2a562d289 100644
--- a/Telegram/SourceFiles/ui/buttons/icon_button.cpp
+++ b/Telegram/SourceFiles/ui/buttons/icon_button.cpp
@@ -49,7 +49,7 @@ void IconButton::onStateChanged(int oldState, ButtonStateChangeSource source) {
 	if (over != (oldState & StateOver)) {
 		auto from = over ? 0. : 1.;
 		auto to = over ? 1. : 0.;
-		START_ANIMATION(_a_over, func(this, &IconButton::updateCallback), from, to, _st.duration, anim::linear);
+		_a_over.start([this] { update(); }, from, to, _st.duration);
 	}
 }
 
diff --git a/Telegram/SourceFiles/ui/buttons/icon_button.h b/Telegram/SourceFiles/ui/buttons/icon_button.h
index 758c59567..488a49df1 100644
--- a/Telegram/SourceFiles/ui/buttons/icon_button.h
+++ b/Telegram/SourceFiles/ui/buttons/icon_button.h
@@ -37,10 +37,6 @@ protected:
 	void onStateChanged(int oldState, ButtonStateChangeSource source) override;
 
 private:
-	void updateCallback() {
-		update();
-	}
-
 	const style::IconButton &_st;
 	const style::icon *_iconOverride = nullptr;
 
diff --git a/Telegram/SourceFiles/ui/effects/fade_animation.cpp b/Telegram/SourceFiles/ui/effects/fade_animation.cpp
index 9936c51e5..5e2663a5d 100644
--- a/Telegram/SourceFiles/ui/effects/fade_animation.cpp
+++ b/Telegram/SourceFiles/ui/effects/fade_animation.cpp
@@ -65,7 +65,9 @@ void FadeAnimation::stopAnimation() {
 		_cache = QPixmap();
 		updateCallback();
 		_widget->showChildren();
-		_finishedCallback.call();
+		if (_finishedCallback) {
+			_finishedCallback();
+		}
 	}
 	if (_visible == _widget->isHidden()) {
 		_widget->setVisible(_visible);
@@ -91,7 +93,9 @@ void FadeAnimation::startAnimation(int duration) {
 		_cache = myGrab(_widget);
 		_widget->hideChildren();
 	}
-	START_ANIMATION(_animation, func(this, &FadeAnimation::updateCallback), _visible ? 0. : 1., _visible ? 1. : 0., duration, anim::linear);
+	auto from = _visible ? 0. : 1.;
+	auto to = _visible ? 1. : 0.;
+	_animation.start([this]() { updateCallback(); }, from, to, duration);
 	updateCallback();
 	if (_widget->isHidden()) {
 		_widget->show();
@@ -101,7 +105,9 @@ void FadeAnimation::startAnimation(int duration) {
 void FadeAnimation::updateCallback() {
 	if (_animation.animating(getms())) {
 		_widget->update();
-		_updatedCallback.call(_animation.current());
+		if (_updatedCallback) {
+			_updatedCallback(_animation.current(_visible ? 1. : 0.));
+		}
 	} else {
 		stopAnimation();
 	}
diff --git a/Telegram/SourceFiles/ui/effects/fade_animation.h b/Telegram/SourceFiles/ui/effects/fade_animation.h
index aaf95129f..4ed09de04 100644
--- a/Telegram/SourceFiles/ui/effects/fade_animation.h
+++ b/Telegram/SourceFiles/ui/effects/fade_animation.h
@@ -31,10 +31,10 @@ public:
 	bool paint(Painter &p);
 	void refreshCache();
 
-	using FinishedCallback = Function<void>;
+	using FinishedCallback = base::lambda_unique<void()>;
 	void setFinishedCallback(FinishedCallback &&callback);
 
-	using UpdatedCallback = Function<void, float64>;
+	using UpdatedCallback = base::lambda_unique<void(float64)>;
 	void setUpdatedCallback(UpdatedCallback &&callback);
 
 	void show();
diff --git a/Telegram/SourceFiles/ui/filedialog.h b/Telegram/SourceFiles/ui/filedialog.h
index c3d774294..a73b97603 100644
--- a/Telegram/SourceFiles/ui/filedialog.h
+++ b/Telegram/SourceFiles/ui/filedialog.h
@@ -65,14 +65,16 @@ bool processQuery();
 
 namespace internal {
 
-using QueryUpdateHandler = Function<void, const QueryUpdate&>;
+using QueryUpdateHandler = base::lambda_unique<void(const QueryUpdate&)>;
 Notify::ConnectionId plainRegisterObserver(QueryUpdateHandler &&handler);
 
 } // namespace internal
 
 template <typename ObserverType>
 void registerObserver(ObserverType *observer, void (ObserverType::*handler)(const QueryUpdate &)) {
-	auto connection = internal::plainRegisterObserver(func(observer, handler));
+	auto connection = internal::plainRegisterObserver([observer, handler](const QueryUpdate &update) {
+		(observer->*handler)(update);
+	});
 	Notify::observerRegistered(observer, connection);
 }
 
diff --git a/Telegram/SourceFiles/ui/flatbutton.cpp b/Telegram/SourceFiles/ui/flatbutton.cpp
index 3ed82ca7b..167d30f86 100644
--- a/Telegram/SourceFiles/ui/flatbutton.cpp
+++ b/Telegram/SourceFiles/ui/flatbutton.cpp
@@ -332,7 +332,7 @@ void EmojiButton::setLoading(bool loading) {
 	if (_loading != loading) {
 		_loading = loading;
 		auto from = loading ? 0. : 1., to = loading ? 1. : 0.;
-		START_ANIMATION(a_loading, func(this, &EmojiButton::updateCallback), from, to, st::emojiCircleDuration, anim::linear);
+		a_loading.start([this] { update(); }, from, to, st::emojiCircleDuration);
 		if (loading) {
 			_a_loading.start();
 		} else {
diff --git a/Telegram/SourceFiles/ui/flatbutton.h b/Telegram/SourceFiles/ui/flatbutton.h
index 83d725615..090b3232f 100644
--- a/Telegram/SourceFiles/ui/flatbutton.h
+++ b/Telegram/SourceFiles/ui/flatbutton.h
@@ -147,12 +147,9 @@ private:
 
 	void step_loading(uint64 ms, bool timer) {
 		if (timer) {
-			updateCallback();
+			update();
 		}
 	}
-	void updateCallback() {
-		update();
-	}
 
 };
 
diff --git a/Telegram/SourceFiles/ui/flatlabel.cpp b/Telegram/SourceFiles/ui/flatlabel.cpp
index e879861d5..909f4e172 100644
--- a/Telegram/SourceFiles/ui/flatlabel.cpp
+++ b/Telegram/SourceFiles/ui/flatlabel.cpp
@@ -232,7 +232,7 @@ Text::StateResult FlatLabel::dragActionFinish(const QPoint &p, Qt::MouseButton b
 	_selectionType = TextSelectType::Letters;
 
 	if (activated) {
-		if (_clickHandlerHook.isNull() || _clickHandlerHook.call(activated, button)) {
+		if (!_clickHandlerHook || _clickHandlerHook(activated, button)) {
 			App::activateClickHandler(activated, button);
 		}
 	}
diff --git a/Telegram/SourceFiles/ui/flatlabel.h b/Telegram/SourceFiles/ui/flatlabel.h
index 978622b79..24e5a3942 100644
--- a/Telegram/SourceFiles/ui/flatlabel.h
+++ b/Telegram/SourceFiles/ui/flatlabel.h
@@ -47,7 +47,7 @@ public:
 
 	void setLink(uint16 lnkIndex, const ClickHandlerPtr &lnk);
 
-	using ClickHandlerHook = Function<bool, const ClickHandlerPtr &, Qt::MouseButton>;
+	using ClickHandlerHook = base::lambda_unique<bool(const ClickHandlerPtr&,Qt::MouseButton)>;
 	void setClickHandlerHook(ClickHandlerHook &&hook);
 
 	// ClickHandlerHost interface
diff --git a/Telegram/SourceFiles/ui/inner_dropdown.cpp b/Telegram/SourceFiles/ui/inner_dropdown.cpp
index ad6ccf238..8065c18e0 100644
--- a/Telegram/SourceFiles/ui/inner_dropdown.cpp
+++ b/Telegram/SourceFiles/ui/inner_dropdown.cpp
@@ -160,12 +160,12 @@ void InnerDropdown::onHideStart() {
 void InnerDropdown::startAnimation() {
 	auto from = _hiding ? 1. : 0.;
 	auto to = _hiding ? 0. : 1.;
-	if (_a_appearance.isNull()) {
+	if (!_a_appearance.animating()) {
 		showChildren();
 		_cache = myGrab(this);
 	}
 	hideChildren();
-	START_ANIMATION(_a_appearance, func(this, &InnerDropdown::repaintCallback), from, to, _st.duration, anim::linear);
+	_a_appearance.start([this] { repaintCallback(); }, from, to, _st.duration);
 }
 
 void InnerDropdown::hidingFinished() {
@@ -186,7 +186,7 @@ void InnerDropdown::showingStarted() {
 
 void InnerDropdown::repaintCallback() {
 	update();
-	if (!_a_appearance.animating(getms()) && _hiding) {
+	if (!_a_appearance.animating() && _hiding) {
 		_hiding = false;
 		hidingFinished();
 	}
diff --git a/Telegram/SourceFiles/ui/inner_dropdown.h b/Telegram/SourceFiles/ui/inner_dropdown.h
index 55974f78e..56f28caec 100644
--- a/Telegram/SourceFiles/ui/inner_dropdown.h
+++ b/Telegram/SourceFiles/ui/inner_dropdown.h
@@ -35,7 +35,7 @@ public:
 	void setOwnedWidget(ScrolledWidget *widget);
 
 	bool overlaps(const QRect &globalRect) {
-		if (isHidden() || !_a_appearance.isNull()) return false;
+		if (isHidden() || _a_appearance.animating()) return false;
 
 		return rect().marginsRemoved(_st.padding).contains(QRect(mapFromGlobal(globalRect.topLeft()), globalRect.size()));
 	}
diff --git a/Telegram/SourceFiles/ui/twidget.cpp b/Telegram/SourceFiles/ui/twidget.cpp
index 2bfac39d8..20053a7b5 100644
--- a/Telegram/SourceFiles/ui/twidget.cpp
+++ b/Telegram/SourceFiles/ui/twidget.cpp
@@ -86,7 +86,7 @@ enum class Mode {
 };
 void ToggleableShadow::setMode(Mode mode) {
 	if (mode == Mode::ShownFast || mode == Mode::HiddenFast) {
-		if (!_a_opacity.isNull()) {
+		if (!_a_opacity.animating()) {
 			_a_opacity.finish();
 			update();
 		}
@@ -94,18 +94,12 @@ void ToggleableShadow::setMode(Mode mode) {
 	if (_shown && (mode == Mode::Hidden || mode == Mode::HiddenFast)) {
 		_shown = false;
 		if (mode == Mode::Hidden) {
-			if (_a_opacity.isNull()) {
-				_a_opacity.setup(1., func(this, &ToggleableShadow::repaintCallback));
-			}
-			_a_opacity.start(0., st::shadowToggleDuration);
+			_a_opacity.start([this] { update(); }, 1., 0., st::shadowToggleDuration);
 		}
 	} else if (!_shown && (mode == Mode::Shown || mode == Mode::ShownFast)) {
 		_shown = true;
 		if (mode == Mode::Shown) {
-			if (_a_opacity.isNull()) {
-				_a_opacity.setup(0., func(this, &ToggleableShadow::repaintCallback));
-			}
-			_a_opacity.start(1., st::shadowToggleDuration);
+			_a_opacity.start([this] { update(); }, 0., 1., st::shadowToggleDuration);
 		}
 	}
 }
diff --git a/Telegram/SourceFiles/ui/twidget.h b/Telegram/SourceFiles/ui/twidget.h
index b12c4da1b..0dc17700b 100644
--- a/Telegram/SourceFiles/ui/twidget.h
+++ b/Telegram/SourceFiles/ui/twidget.h
@@ -268,17 +268,13 @@ public:
 	void setMode(Mode mode);
 
 	bool isFullyShown() const {
-		return _shown && _a_opacity.isNull();
+		return _shown && !_a_opacity.animating();
 	}
 
 protected:
 	void paintEvent(QPaintEvent *e) override;
 
 private:
-	void repaintCallback() {
-		update();
-	}
-
 	const style::color &_color;
 	FloatAnimation _a_opacity;
 	bool _shown = true;
diff --git a/Telegram/SourceFiles/window/section_widget.cpp b/Telegram/SourceFiles/window/section_widget.cpp
index 47c085446..a1f13eed2 100644
--- a/Telegram/SourceFiles/window/section_widget.cpp
+++ b/Telegram/SourceFiles/window/section_widget.cpp
@@ -50,8 +50,8 @@ void SectionWidget::showAnimated(SlideDirection direction, const SectionSlidePar
 
 	_showAnimation = std_::make_unique<SlideAnimation>();
 	_showAnimation->setDirection(direction);
-	_showAnimation->setRepaintCallback(func(this, &SectionWidget::repaintCallback));
-	_showAnimation->setFinishedCallback(func(this, &SectionWidget::showFinished));
+	_showAnimation->setRepaintCallback([this] { update(); });
+	_showAnimation->setFinishedCallback([this] { showFinished(); });
 	_showAnimation->setPixmaps(params.oldContentCache, myContentCache);
 	_showAnimation->setTopBarShadow(params.withTopBarShadow);
 	_showAnimation->start();
diff --git a/Telegram/SourceFiles/window/section_widget.h b/Telegram/SourceFiles/window/section_widget.h
index b77377fbe..ca72b0dd7 100644
--- a/Telegram/SourceFiles/window/section_widget.h
+++ b/Telegram/SourceFiles/window/section_widget.h
@@ -89,10 +89,6 @@ protected:
 	}
 
 private:
-	// QWidget::update() method is overloaded and we need template deduction.
-	void repaintCallback() {
-		update();
-	}
 	void showFinished();
 
 	std_::unique_ptr<SlideAnimation> _showAnimation;
diff --git a/Telegram/SourceFiles/window/slide_animation.cpp b/Telegram/SourceFiles/window/slide_animation.cpp
index 5f53e98fa..fb9ab988e 100644
--- a/Telegram/SourceFiles/window/slide_animation.cpp
+++ b/Telegram/SourceFiles/window/slide_animation.cpp
@@ -92,7 +92,9 @@ void SlideAnimation::step(float64 ms, bool timer) {
 			a_coordUnder.finish();
 			a_coordOver.finish();
 
-			_finishedCallback.call();
+			if (_finishedCallback) {
+				_finishedCallback();
+			}
 			return;
 		}
 	}
@@ -100,8 +102,8 @@ void SlideAnimation::step(float64 ms, bool timer) {
 	a_coordUnder.update(dt, st::slideFunction);
 	a_coordOver.update(dt, st::slideFunction);
 	a_progress.update(dt, st::slideFunction);
-	if (timer) {
-		_repaintCallback.call();
+	if (timer && _repaintCallback) {
+		_repaintCallback();
 	}
 }
 
diff --git a/Telegram/SourceFiles/window/slide_animation.h b/Telegram/SourceFiles/window/slide_animation.h
index 5ce4068ae..53a24c3b6 100644
--- a/Telegram/SourceFiles/window/slide_animation.h
+++ b/Telegram/SourceFiles/window/slide_animation.h
@@ -37,10 +37,10 @@ public:
 	void setPixmaps(const QPixmap &oldContentCache, const QPixmap &newContentCache);
 	void setTopBarShadow(bool enabled);
 
-	using RepaintCallback = Function<void>;
+	using RepaintCallback = base::lambda_unique<void()>;
 	void setRepaintCallback(RepaintCallback &&callback);
 
-	using FinishedCallback = Function<void>;
+	using FinishedCallback = base::lambda_unique<void()>;
 	void setFinishedCallback(FinishedCallback &&callback);
 
 	void start();