diff --git a/src/cpp/cpp_declaration.cpp b/src/cpp/cpp_declaration.cpp
index a01afe82aa3..42fdb2d44c3 100644
--- a/src/cpp/cpp_declaration.cpp
+++ b/src/cpp/cpp_declaration.cpp
@@ -15,17 +15,17 @@ Author: Daniel Kroening, kroening@cs.cmu.edu
 
 void cpp_declarationt::output(std::ostream &out) const
 {
-  out << "is_template: " << is_template() << "\n";
-  out << "storage: " << storage_spec().pretty() << "\n";
-  out << "template_type: " << template_type().pretty() << "\n";
-  out << "type: " << type().pretty() << "\n";
+  out << "is_template: " << is_template() << '\n';
+  out << "storage: " << storage_spec().pretty() << '\n';
+  out << "template_type: " << template_type().pretty() << '\n';
+  out << "type: " << type().pretty() << '\n';
 
-  out << "Declarators:" << "\n";
+  out << "Declarators:" << '\n';
 
   for(const auto &it : declarators())
   {
     it.output(out);
-    out << "\n";
+    out << '\n';
   }
 }
 
diff --git a/src/cpp/cpp_declarator.cpp b/src/cpp/cpp_declarator.cpp
index e348309dc47..6a146f328d9 100644
--- a/src/cpp/cpp_declarator.cpp
+++ b/src/cpp/cpp_declarator.cpp
@@ -18,11 +18,11 @@ Author: Daniel Kroening, kroening@cs.cmu.edu
 
 void cpp_declaratort::output(std::ostream &out) const
 {
-  out << "  name: " << name().pretty() << "\n";
-  out << "  type: " << type().pretty() << "\n";
-  out << "  value: " << value().pretty() << "\n";
-  out << "  init_args: " << init_args().pretty() << "\n";
-  out << "  method_qualifier: " << method_qualifier().pretty() << "\n";
+  out << "  name: " << name().pretty() << '\n';
+  out << "  type: " << type().pretty() << '\n';
+  out << "  value: " << value().pretty() << '\n';
+  out << "  init_args: " << init_args().pretty() << '\n';
+  out << "  method_qualifier: " << method_qualifier().pretty() << '\n';
 }
 
 typet cpp_declaratort::merge_type(const typet &declaration_type) const
diff --git a/src/cpp/cpp_declarator_converter.cpp b/src/cpp/cpp_declarator_converter.cpp
index 13b9f4821ac..4f58318c421 100644
--- a/src/cpp/cpp_declarator_converter.cpp
+++ b/src/cpp/cpp_declarator_converter.cpp
@@ -344,20 +344,24 @@ void cpp_declarator_convertert::handle_initializer(
   }
   else
   {
-    #if 0
-    cpp_typecheck.error().source_location=declarator.name());
+#if 0
+    cpp_typecheck.error().source_location=source_location;
 
     if(is_code)
-      cpp_typecheck.str << "body of function `"
+    {
+      cpp_typecheck.error() << "body of function `"
                         << symbol.display_name()
-                        << "' has already been defined";
+                        << "' has already been defined" << messaget::eom;
+    }
     else
-      cpp_typecheck.str << "symbol `"
+    {
+      cpp_typecheck.error() << "symbol `"
                         << symbol.display_name()
-                        << "' already has an initializer";
+                        << "' already has an initializer" << messaget::eom;
+    }
 
     throw 0;
-    #endif
+#endif
   }
 }
 
diff --git a/src/cpp/cpp_namespace_spec.cpp b/src/cpp/cpp_namespace_spec.cpp
index 2254f2b7d34..e24164c08a4 100644
--- a/src/cpp/cpp_namespace_spec.cpp
+++ b/src/cpp/cpp_namespace_spec.cpp
@@ -17,5 +17,5 @@ Author: Daniel Kroening, kroening@cs.cmu.edu
 
 void cpp_namespace_spect::output(std::ostream &out) const
 {
-  out << "  namespace: " << get_namespace() << "\n";
+  out << "  namespace: " << get_namespace() << '\n';
 }
diff --git a/src/cpp/cpp_scopes.cpp b/src/cpp/cpp_scopes.cpp
index 71a6b1edfbf..aa7ea8c6a99 100644
--- a/src/cpp/cpp_scopes.cpp
+++ b/src/cpp/cpp_scopes.cpp
@@ -76,7 +76,7 @@ void cpp_scopest::print_current(std::ostream &out) const
   do
   {
     scope->print_fields(out);
-    out << "\n";
+    out << '\n';
     scope=&scope->get_parent();
   }
   while(!scope->is_root_scope());
diff --git a/src/cpp/cpp_typecheck.cpp b/src/cpp/cpp_typecheck.cpp
index f5076cb4abc..bd76880f14d 100644
--- a/src/cpp/cpp_typecheck.cpp
+++ b/src/cpp/cpp_typecheck.cpp
@@ -337,8 +337,11 @@ bool cpp_typecheckt::contains_cpp_name(const exprt &expr)
 {
   if(expr.id() == ID_cpp_name || expr.id() == ID_cpp_declaration)
     return true;
-  forall_operands(it, expr)
-    if(contains_cpp_name(*it))
+
+  for(const exprt &op : expr.operands())
+  {
+    if(contains_cpp_name(op))
       return true;
+  }
   return false;
 }
diff --git a/src/cpp/cpp_typecheck_compound_type.cpp b/src/cpp/cpp_typecheck_compound_type.cpp
index ebaa795f453..d9e0fe6fa85 100644
--- a/src/cpp/cpp_typecheck_compound_type.cpp
+++ b/src/cpp/cpp_typecheck_compound_type.cpp
@@ -1325,12 +1325,9 @@ void cpp_typecheckt::typecheck_member_function(
   if(symbol_table.move(symbol, new_symbol))
   {
     error().source_location=symbol.location;
-    error() << "failed to insert new method symbol: "
-            << symbol.name << "\n"
-            << "name of previous symbol: "
-            << new_symbol->name << "\n"
-            << "location of previous symbol: "
-            << new_symbol->location << eom;
+    error() << "failed to insert new method symbol: " << symbol.name << '\n'
+            << "name of previous symbol: " << new_symbol->name << '\n'
+            << "location of previous symbol: " << new_symbol->location << eom;
 
     throw 0;
   }
diff --git a/src/cpp/cpp_typecheck_declaration.cpp b/src/cpp/cpp_typecheck_declaration.cpp
index 800b494859b..1a221e29254 100644
--- a/src/cpp/cpp_typecheck_declaration.cpp
+++ b/src/cpp/cpp_typecheck_declaration.cpp
@@ -6,7 +6,6 @@ Author: Daniel Kroening, kroening@cs.cmu.edu
 
 \********************************************************************/
 
-
 /// \file
 /// C++ Language Type Checking
 
diff --git a/src/cpp/cpp_typecheck_expr.cpp b/src/cpp/cpp_typecheck_expr.cpp
index e924a77baf1..3ee7d3756d3 100644
--- a/src/cpp/cpp_typecheck_expr.cpp
+++ b/src/cpp/cpp_typecheck_expr.cpp
@@ -2344,7 +2344,7 @@ void cpp_typecheckt::typecheck_method_application(
       static_cast<const cpp_template_args_tct &>(template_args));
     add_method_body(&method_symbol);
 #ifdef DEBUG
-    std::cout << "MAP for " << symbol << ":" << std::endl;
+    std::cout << "MAP for " << symbol << ":\n";
     template_map.print(std::cout);
 #endif
   }
diff --git a/src/cpp/cpp_typecheck_method_bodies.cpp b/src/cpp/cpp_typecheck_method_bodies.cpp
index 53427c23121..e8389d721be 100644
--- a/src/cpp/cpp_typecheck_method_bodies.cpp
+++ b/src/cpp/cpp_typecheck_method_bodies.cpp
@@ -37,9 +37,9 @@ void cpp_typecheckt::typecheck_method_bodies()
       continue;
 
 #ifdef DEBUG
-  std::cout << "convert_method_body: " << method_symbol.name << std::endl;
-  std::cout << "  is_not_nil: " << body.is_not_nil() << std::endl;
-  std::cout << "  !is_zero: " << (!body.is_zero()) << std::endl;
+    std::cout << "convert_method_body: " << method_symbol.name << '\n';
+    std::cout << "  is_not_nil: " << body.is_not_nil() << '\n';
+    std::cout << "  !is_zero: " << (!body.is_zero()) << '\n';
 #endif
     if(body.is_not_nil() && !body.is_zero())
       convert_function(method_symbol);
@@ -51,22 +51,18 @@ void cpp_typecheckt::typecheck_method_bodies()
 void cpp_typecheckt::add_method_body(symbolt *_method_symbol)
 {
 #ifdef DEBUG
-  std::cout << "add_method_body: " << _method_symbol->name << std::endl;
+  std::cout << "add_method_body: " << _method_symbol->name << '\n';
 #endif
-
-  // We have to prevent the same method to be added multiple times
-  //   otherwise we get duplicated symbol prefixes
-  if(methods_seen.find(_method_symbol->name) != methods_seen.end())
+  // Converting a method body might add method bodies for methods that we have
+  // already analyzed. Adding the same method more than once causes duplicated
+  // symbol prefixes, therefore we have to keep track.
+  if(methods_seen.insert(_method_symbol->name).second)
   {
+    method_bodies.push_back(
+      method_bodyt(_method_symbol, template_map, instantiation_stack));
+  }
 #ifdef DEBUG
-    std::cout << "  already exists" << std::endl;
+  else
+    std::cout << "  already exists\n";
 #endif
-    return;
-  }
-  method_bodies.push_back(
-    method_bodyt(_method_symbol, template_map, instantiation_stack));
-
-  // Converting a method body might add method bodies for methods
-  // that we have already analyzed. Hence, we have to keep track.
-  methods_seen.insert(_method_symbol->name);
 }
diff --git a/src/cpp/cpp_typecheck_resolve.cpp b/src/cpp/cpp_typecheck_resolve.cpp
index 529a5703f9b..6590838142d 100644
--- a/src/cpp/cpp_typecheck_resolve.cpp
+++ b/src/cpp/cpp_typecheck_resolve.cpp
@@ -183,7 +183,7 @@ exprt cpp_typecheck_resolvet::convert_template_parameter(
   const cpp_idt &identifier)
 {
 #ifdef DEBUG
-  std::cout << "RESOLVE MAP:" << std::endl;
+  std::cout << "RESOLVE MAP:\n";
   cpp_typecheck.template_map.print(std::cout);
 #endif
 
@@ -1183,8 +1183,8 @@ struct_tag_typet cpp_typecheck_resolvet::disambiguate_template_classes(
   if(instance.type.id()!=ID_struct)
   {
     cpp_typecheck.error().source_location=source_location;
-    cpp_typecheck.str << "template `"
-                      << base_name << "' is not a class";
+    cpp_typecheck.error() << "template `"
+                      << base_name << "' is not a class" << messaget::eom;
     throw 0;
   }
 
@@ -1360,11 +1360,11 @@ exprt cpp_typecheck_resolvet::resolve(
   resolve_scope(cpp_name, base_name, template_args);
 
 #ifdef DEBUG
-  std::cout << "base name: " << base_name << std::endl;
-  std::cout << "template args: " << template_args.pretty() << std::endl;
-  std::cout << "original-scope: " << original_scope->prefix << std::endl;
-  std::cout << "scope: "
-            << cpp_typecheck.cpp_scopes.current_scope().prefix << std::endl;
+  std::cout << "base name: " << base_name << '\n';
+  std::cout << "template args: " << template_args.pretty() << '\n';
+  std::cout << "original-scope: " << original_scope->prefix << '\n';
+  std::cout << "scope: " << cpp_typecheck.cpp_scopes.current_scope().prefix
+            << '\n';
 #endif
 
   bool qualified=cpp_name.is_qualified();
@@ -1517,11 +1517,11 @@ exprt cpp_typecheck_resolvet::resolve(
 
   filter(identifiers, want);
 
-  #if 0
-  std::cout << "P0 " << base_name << " " << identifiers.size() << "\n";
+#ifdef DEBUG
+  std::cout << "P0 " << base_name << " " << identifiers.size() << '\n';
   show_identifiers(base_name, identifiers, std::cout);
-  std::cout << "\n";
-  #endif
+  std::cout << '\n';
+#endif
 
   exprt result;
 
@@ -1530,20 +1530,20 @@ exprt cpp_typecheck_resolvet::resolve(
 
   remove_templates(new_identifiers);
 
-  #if 0
-  std::cout << "P1 " << base_name << " " << new_identifiers.size() << "\n";
+#ifdef DEBUG
+  std::cout << "P1 " << base_name << " " << new_identifiers.size() << '\n';
   show_identifiers(base_name, new_identifiers, std::cout);
-  std::cout << "\n";
-  #endif
+  std::cout << '\n';
+#endif
 
   // we only want _exact_ matches, without templates!
   exact_match_functions(new_identifiers, fargs);
 
-  #if 0
-  std::cout << "P2 " << base_name << " " << new_identifiers.size() << "\n";
+#ifdef DEBUG
+  std::cout << "P2 " << base_name << " " << new_identifiers.size() << '\n';
   show_identifiers(base_name, new_identifiers, std::cout);
-  std::cout << "\n";
-  #endif
+  std::cout << '\n';
+#endif
 
   // no exact matches? Try again with function template guessing.
   if(new_identifiers.empty())
@@ -1560,20 +1560,20 @@ exprt cpp_typecheck_resolvet::resolve(
 
     disambiguate_functions(new_identifiers, fargs);
 
-    #if 0
-    std::cout << "P3 " << base_name << " " << new_identifiers.size() << "\n";
+#ifdef DEBUG
+    std::cout << "P3 " << base_name << " " << new_identifiers.size() << '\n';
     show_identifiers(base_name, new_identifiers, std::cout);
-    std::cout << "\n";
-    #endif
+    std::cout << '\n';
+#endif
   }
 
   remove_duplicates(new_identifiers);
 
-  #if 0
-  std::cout << "P4 " << base_name << " " << new_identifiers.size() << "\n";
+#ifdef DEBUG
+  std::cout << "P4 " << base_name << " " << new_identifiers.size() << '\n';
   show_identifiers(base_name, new_identifiers, std::cout);
-  std::cout << "\n";
-  #endif
+  std::cout << '\n';
+#endif
 
   if(new_identifiers.size()==1)
   {
@@ -1601,20 +1601,20 @@ exprt cpp_typecheck_resolvet::resolve(
         << "' does not uniquely resolve:\n";
       show_identifiers(base_name, new_identifiers, cpp_typecheck.error());
 
-      #if 0
+#ifdef DEBUG
       exprt e1=*new_identifiers.begin();
       exprt e2=*(++new_identifiers.begin());
-      cpp_typecheck.str << "e1==e2: " << (e1==e2) << '\n';
-      cpp_typecheck.str << "e1.type==e2.type: " << (e1.type()==e2.type())
-                        << '\n';
-      cpp_typecheck.str << "e1.id()==e2.id(): " << (e1.id()==e2.id())
-                        << '\n';
-      cpp_typecheck.str << "e1.iden==e2.iden: "
-                        << (e1.get(ID_identifier)==e2.get(ID_identifier))
-                        << '\n';
-      cpp_typecheck.str << "e1.iden:: " << e1.get(ID_identifier) << '\n';
-      cpp_typecheck.str << "e2.iden:: " << e2.get(ID_identifier) << '\n';
-      #endif
+      cpp_typecheck.error() << "e1==e2: " << (e1 == e2) << '\n';
+      cpp_typecheck.error()
+        << "e1.type==e2.type: " << (e1.type() == e2.type()) << '\n';
+      cpp_typecheck.error()
+        << "e1.id()==e2.id(): " << (e1.id() == e2.id()) << '\n';
+      cpp_typecheck.error()
+        << "e1.iden==e2.iden: "
+        << (e1.get(ID_identifier) == e2.get(ID_identifier)) << '\n';
+      cpp_typecheck.error() << "e1.iden:: " << e1.get(ID_identifier) << '\n';
+      cpp_typecheck.error() << "e2.iden:: " << e2.get(ID_identifier) << '\n';
+#endif
     }
 
     if(fargs.in_use)
diff --git a/src/cpp/parse.cpp b/src/cpp/parse.cpp
index 31057fe8cd6..7de7d52e1ae 100644
--- a/src/cpp/parse.cpp
+++ b/src/cpp/parse.cpp
@@ -190,10 +190,8 @@ void new_scopet::print_rec(std::ostream &out, unsigned indent) const
       it!=id_map.end();
       it++)
   {
-    out << std::string(indent, ' ')
-        << it->first << ": "
-        << kind2string(it->second.kind)
-        << "\n";
+    out << std::string(indent, ' ') << it->first << ": "
+        << kind2string(it->second.kind) << '\n';
     it->second.print_rec(out, indent+2);
   }
 }
@@ -1455,7 +1453,7 @@ bool Parser::rDeclaration(cpp_declarationt &declaration)
 
 #ifdef DEBUG
     std::cout << std::string(__indent, ' ') << "Parser::rDeclaration 6 " << t
-              << "\n";
+              << '\n';
 #endif
 
     if(cv_q.is_not_nil() &&
@@ -1537,7 +1535,7 @@ bool Parser::rIntegralDeclaration(
   indenter _i;
   std::cout << std::string(__indent, ' ')
             << "Parser::rIntegralDeclaration 1  token: "
-            << static_cast<char>(lex.LookAhead(0)) << "\n";
+            << static_cast<char>(lex.LookAhead(0)) << '\n';
 #endif
 
   if(!optCvQualify(cv_q))
@@ -1593,9 +1591,8 @@ bool Parser::rIntegralDeclaration(
 
   default:
 #ifdef DEBUG
-    std::cout << std::string(__indent, ' ')
-              << "Parser::rIntegralDeclaration 6 "
-              << lex.LookAhead(0) << "\n";
+    std::cout << std::string(__indent, ' ') << "Parser::rIntegralDeclaration 6 "
+              << lex.LookAhead(0) << '\n';
 #endif
 
     if(!rDeclarators(declaration.declarators(), true))
@@ -1858,7 +1855,7 @@ bool Parser::isConstructorDecl()
 #ifdef DEBUG
   indenter _i;
   std::cout << std::string(__indent, ' ') << "Parser::isConstructorDecl "
-            << lex.LookAhead(0) << "  "<< lex.LookAhead(1) << "\n";
+            << lex.LookAhead(0) << "  " << lex.LookAhead(1) << '\n';
 #endif
 
   if(lex.LookAhead(0)!='(')
@@ -3261,8 +3258,8 @@ bool Parser::optPtrOperator(typet &ptrs)
     int t=lex.LookAhead(0);
 
 #ifdef DEBUG
-    std::cout << std::string(__indent, ' ') << "Parser::optPtrOperator 2 "
-              << t << "\n";
+    std::cout << std::string(__indent, ' ') << "Parser::optPtrOperator 2 " << t
+              << '\n';
 #endif
 
     if(t=='*')
@@ -3514,7 +3511,7 @@ bool Parser::rName(irept &name)
 
 #ifdef DEBUG
     std::cout << std::string(__indent, ' ') << "Parser::rName 2 "
-              << lex.LookAhead(0) << "\n";
+              << lex.LookAhead(0) << '\n';
 #endif
 
     switch(lex.LookAhead(0))
@@ -7283,7 +7280,7 @@ optionalt<codet> Parser::rStatement()
 #ifdef DEBUG
   indenter _i;
   std::cout << std::string(__indent, ' ') << "Parser::rStatement 0 "
-            << lex.LookAhead(0) << "\n";
+            << lex.LookAhead(0) << '\n';
 #endif
 
   switch(k=lex.LookAhead(0))
@@ -8113,7 +8110,7 @@ optionalt<codet> Parser::rExprStatement()
 
 #ifdef DEBUG
       std::cout << std::string(__indent, ' ') << "Parser::rExprStatement 5 "
-                << lex.LookAhead(0) << "\n";
+                << lex.LookAhead(0) << '\n';
 #endif
 
       if(lex.get_token(tk)!=';')
@@ -8212,7 +8209,7 @@ optionalt<codet> Parser::rDeclarationStatement()
 
 #ifdef DEBUG
     std::cout << std::string(__indent, ' ')
-              << "Parser::rDeclarationStatement 3 " << t << "\n";
+              << "Parser::rDeclarationStatement 3 " << t << '\n';
 #endif
 
     if(cv_q.is_not_nil() &&