Add and use mapTuple helper.

libsolutil/CommonData.h

@@ -265,6 +265,39 @@ decltype(auto) valueOrDefault(MapType&& _map, KeyType const& _key, ValueType&& _
 	return (it == _map.end()) ? _defaultValue : it->second;
 }
 
+namespace detail
+{
+template<typename Callable>
+struct MapTuple
+{
+	Callable callable;
+	template<typename TupleType>
+	decltype(auto) operator()(TupleType&& _tuple) {
+		using PlainTupleType = std::remove_cv_t<std::remove_reference_t<TupleType>>;
+		return operator()(
+			std::forward<TupleType>(_tuple),
+			std::make_index_sequence<std::tuple_size_v<PlainTupleType>>{}
+		);
+	}
+private:
+	template<typename TupleType, size_t... I>
+	decltype(auto) operator()(TupleType&& _tuple, std::index_sequence<I...>)
+	{
+		return callable(std::get<I>(std::forward<TupleType>(_tuple))...);
+	}
+};
+}
+
+/// Wraps @a _callable, which takes multiple arguments, into a callable that takes a single tuple of arguments.
+/// Since structured binding in lambdas is not allowed, i.e. [](auto&& [key, value]) { ... } is invalid, this allows
+/// to instead use mapTuple([](auto&& key, auto&& value) { ... }).
+template<typename Callable>
+decltype(auto) mapTuple(Callable&& _callable)
+{
+	return detail::MapTuple<Callable>{std::forward<Callable>(_callable)};
+}
+
+
 // String conversion functions, mainly to/from hex/nibble/byte representations.
 
 enum class WhenError

libyul/optimiser/DataFlowAnalyzer.cpp

@@ -63,19 +63,19 @@ void DataFlowAnalyzer::operator()(ExpressionStatement& _statement)
 	if (auto vars = isSimpleStore(StoreLoadLocation::Storage, _statement))
 	{
 		ASTModifier::operator()(_statement);
-		cxx20::erase_if(m_storage, [&](auto const& entry) {
+		cxx20::erase_if(m_storage, mapTuple([&](auto&& key, auto&& value) {
 			return
-				!m_knowledgeBase.knownToBeDifferent(vars->first, entry.first) &&
+				!m_knowledgeBase.knownToBeDifferent(vars->first, key) &&
-				!m_knowledgeBase.knownToBeEqual(vars->second, entry.second);
+				!m_knowledgeBase.knownToBeEqual(vars->second, value);
-		});
+		}));
 		m_storage[vars->first] = vars->second;
 	}
 	else if (auto vars = isSimpleStore(StoreLoadLocation::Memory, _statement))
 	{
 		ASTModifier::operator()(_statement);
-		cxx20::erase_if(m_memory, [&](auto const& entry) {
+		cxx20::erase_if(m_memory, mapTuple([&](auto&& key, auto&& /* value */) {
-			return !m_knowledgeBase.knownToBeDifferentByAtLeast32(vars->first, entry.first);
+			return !m_knowledgeBase.knownToBeDifferentByAtLeast32(vars->first, key);
-		});
+		}));
 		m_memory[vars->first] = vars->second;
 	}
 	else
@@ -261,11 +261,11 @@ void DataFlowAnalyzer::handleAssignment(set<YulString> const& _variables, Expres
 			// assignment to slot denoted by "name"
 			m_storage.erase(name);
 			// assignment to slot contents denoted by "name"
-			cxx20::erase_if(m_storage, [&](auto const& entry) { return entry.second == name; });
+			cxx20::erase_if(m_storage, mapTuple([&name](auto&& /* key */, auto&& value) { return value == name; }));
 			// assignment to slot denoted by "name"
 			m_memory.erase(name);
 			// assignment to slot contents denoted by "name"
-			cxx20::erase_if(m_memory, [&](auto const& entry) { return entry.second == name; });
+			cxx20::erase_if(m_memory, mapTuple([&name](auto&& /* key */, auto&& value) { return value == name; }));
 		}
 	}
 
@@ -318,9 +318,9 @@ void DataFlowAnalyzer::clearValues(set<YulString> _variables)
 	// First clear storage knowledge, because we do not have to clear
 	// storage knowledge of variables whose expression has changed,
 	// since the value is still unchanged.
-	auto eraseCondition = [&](auto const& entry) {
+	auto eraseCondition = mapTuple([&_variables](auto&& key, auto&& value) {
-		return _variables.count(entry.first) || _variables.count(entry.second);
+		return _variables.count(key) || _variables.count(value);
-	};
+	});
 	cxx20::erase_if(m_storage, eraseCondition);
 	cxx20::erase_if(m_memory, eraseCondition);
 
@@ -379,10 +379,10 @@ void DataFlowAnalyzer::joinKnowledgeHelper(
 	// This also works for memory because _older is an "older version"
 	// of m_memory and thus any overlapping write would have cleared the keys
 	// that are not known to be different inside m_memory already.
-	cxx20::erase_if(_this, [&](auto const& entry){
+	cxx20::erase_if(_this, mapTuple([&_older](auto&& key, auto&& currentValue){
-		YulString const* value = valueOrNullptr(_older, entry.first);
+		YulString const* oldValue = valueOrNullptr(_older, key);
-		return !value || *value != entry.second;
+		return !oldValue || *oldValue != currentValue;
-	});
+	}));
 }
 
 bool DataFlowAnalyzer::inScope(YulString _variableName) const