Index: src/Common/ScopedMap.h
===================================================================
--- src/Common/ScopedMap.h	(revision 2f61765f9afcb6b5959d0f1348c59fbe33f05d88)
+++ src/Common/ScopedMap.h	(revision e9b50434ce6bdadbbeec1c812d5b5c1b1322637d)
@@ -181,4 +181,8 @@
 		return c;
 	}
+
+	bool contains( const Key & key ) const {
+		return find( key ) != cend();
+	}
 };
 
Index: src/GenPoly/Box.cc
===================================================================
--- src/GenPoly/Box.cc	(revision 2f61765f9afcb6b5959d0f1348c59fbe33f05d88)
+++ src/GenPoly/Box.cc	(revision e9b50434ce6bdadbbeec1c812d5b5c1b1322637d)
@@ -488,5 +488,5 @@
 				for ( FunctionType const * const funType : functions ) {
 					std::string mangleName = mangleAdapterName( funType, scopeTyVars );
-					if ( adapters.find( mangleName ) == adapters.end() ) {
+					if ( !adapters.contains( mangleName ) ) {
 						std::string adapterName = makeAdapterName( mangleName );
 						adapters.insert( std::pair< std::string, DeclarationWithType *>( mangleName, new ObjectDecl( adapterName, Type::StorageClasses(), LinkageSpec::C, nullptr, new PointerType( Type::Qualifiers(), makeAdapterType( funType, scopeTyVars ) ), nullptr ) ) );
@@ -1487,5 +1487,5 @@
 					if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( ty ) ) {
 						// do not try to monomorphize generic parameters
-						if ( scopeTyVars.find( typeInst->get_name() ) != scopeTyVars.end() && ! genericParams.count( typeInst->name ) ) {
+						if ( scopeTyVars.contains( typeInst->get_name() ) && ! genericParams.count( typeInst->name ) ) {
 							// polymorphic aggregate members should be converted into monomorphic members.
 							// Using char[size_T] here respects the expected sizing rules of an aggregate type.
@@ -1696,5 +1696,5 @@
 
 			if ( auto typeInst = dynamic_cast< TypeInstType const * >( ty ) ) {
-				if ( scopeTyVars.find( typeInst->get_name() ) != scopeTyVars.end() ) {
+				if ( scopeTyVars.contains( typeInst->get_name() ) ) {
 					// NOTE assumes here that getting put in the scopeTyVars included having the layout variables set
 					return true;
@@ -1704,5 +1704,5 @@
 				// check if this type already has a layout generated for it
 				std::string typeName = mangleType( ty );
-				if ( knownLayouts.find( typeName ) != knownLayouts.end() ) return true;
+				if ( knownLayouts.contains( typeName ) ) return true;
 
 				// check if any of the type parameters have dynamic layout; if none do, this type is (or will be) monomorphized
@@ -1741,5 +1741,5 @@
 				// check if this type already has a layout generated for it
 				std::string typeName = mangleType( ty );
-				if ( knownLayouts.find( typeName ) != knownLayouts.end() ) return true;
+				if ( knownLayouts.contains( typeName ) ) return true;
 
 				// check if any of the type parameters have dynamic layout; if none do, this type is (or will be) monomorphized
@@ -1832,5 +1832,5 @@
 			} else {
 				std::string offsetName = offsetofName( mangleType( ty ) );
-				if ( knownOffsets.find( offsetName ) != knownOffsets.end() ) {
+				if ( knownOffsets.contains( offsetName ) ) {
 					// use the already-generated offsets for this type
 					ret = new NameExpr( offsetName );
Index: src/GenPoly/ErasableScopedMap.h
===================================================================
--- src/GenPoly/ErasableScopedMap.h	(revision 2f61765f9afcb6b5959d0f1348c59fbe33f05d88)
+++ src/GenPoly/ErasableScopedMap.h	(revision e9b50434ce6bdadbbeec1c812d5b5c1b1322637d)
@@ -5,5 +5,5 @@
 // file "LICENCE" distributed with Cforall.
 //
-// ScopedMap.h --
+// ErasableScopedMap.h --
 //
 // Author           : Aaron B. Moss
@@ -118,4 +118,10 @@
 	std::pair< iterator, bool > insert( const Key &key, const Value &value ) { return insert( std::make_pair( key, value ) ); }
 
+	Value& operator[] ( const Key &key ) {
+		iterator slot = find( key );
+		if ( slot != end() ) return slot->second;
+		return insert( key, Value() ).first->second;
+	}
+
 	/// Marks the given element as erased from this scope inward; returns 1 for erased an element, 0 otherwise
 	size_type erase( const Key &key ) {
@@ -130,8 +136,6 @@
 	}
 
-	Value& operator[] ( const Key &key ) {
-		iterator slot = find( key );
-		if ( slot != end() ) return slot->second;
-		return insert( key, Value() ).first->second;
+	bool contains( const Key & key ) const {
+		return find( key ) != cend();
 	}
 };
Index: src/GenPoly/GenPoly.cc
===================================================================
--- src/GenPoly/GenPoly.cc	(revision 2f61765f9afcb6b5959d0f1348c59fbe33f05d88)
+++ src/GenPoly/GenPoly.cc	(revision e9b50434ce6bdadbbeec1c812d5b5c1b1322637d)
@@ -172,5 +172,5 @@
 
 		if ( TypeInstType *typeInst = dynamic_cast< TypeInstType * >( type ) ) {
-			if ( tyVars.find( typeInst->get_name() ) != tyVars.end() ) {
+			if ( tyVars.contains( typeInst->get_name() ) ) {
 				return type;
 			}
@@ -189,5 +189,5 @@
 
 		if ( auto typeInst = dynamic_cast< const ast::TypeInstType * >( type ) ) {
-			return tyVars.find(typeInst->typeString()) != tyVars.end() ? type : nullptr;
+			if ( tyVars.contains( typeInst->typeString() ) ) return type;
 		} else if ( auto arrayType = dynamic_cast< const ast::ArrayType * >( type ) ) {
 			return isPolyType( arrayType->base, env );
@@ -205,5 +205,5 @@
 
 	if ( auto inst = dynamic_cast< const ast::TypeInstType * >( type ) ) {
-		if ( typeVars.find( *inst ) != typeVars.end() ) return type;
+		if ( typeVars.contains( *inst ) ) return type;
 	} else if ( auto array = dynamic_cast< const ast::ArrayType * >( type ) ) {
 		return isPolyType( array->base, subst );
@@ -393,5 +393,5 @@
 
 		if ( TypeInstType *typeInstType = dynamic_cast< TypeInstType * >( type ) ) {
-			if ( tyVars.find( typeInstType->get_name() ) != tyVars.end() ) {
+			if ( tyVars.contains( typeInstType->get_name() ) ) {
 				return true;
 			}
Index: src/GenPoly/ScopedSet.h
===================================================================
--- src/GenPoly/ScopedSet.h	(revision 2f61765f9afcb6b5959d0f1348c59fbe33f05d88)
+++ src/GenPoly/ScopedSet.h	(revision e9b50434ce6bdadbbeec1c812d5b5c1b1322637d)
@@ -29,5 +29,6 @@
 	typedef std::vector< Scope > ScopeList;
 
-	ScopeList scopes; ///< scoped list of sets
+	/// Scoped list of sets.
+	ScopeList scopes;
 public:
 	typedef typename Scope::key_type key_type;
@@ -100,4 +101,8 @@
 		return std::make_pair( iterator(scopes, res.first, scopes.size()-1), res.second );
 	}
+
+	bool contains( const Value & key ) const {
+		return find( key ) != cend();
+	}
 };