diff -Nuar freehdl-0.0.8.orig/fire/test-fire.cc freehdl-0.0.8/fire/test-fire.cc
--- freehdl-0.0.8.orig/fire/test-fire.cc	2006-02-16 10:56:22.000000000 +0200
+++ freehdl-0.0.8/fire/test-fire.cc	2020-03-30 02:54:42.423609306 +0300
@@ -2,7 +2,7 @@
 #include <stdio.h>
 #include <freehdl/fire.h>
 
-using namespace std;
+using std::cout;
 
 extern tree_chunk_info fire_chunk_info;
 
diff -Nuar freehdl-0.0.8.orig/freehdl/cdfggen-chunk.h freehdl-0.0.8/freehdl/cdfggen-chunk.h
--- freehdl-0.0.8.orig/freehdl/cdfggen-chunk.h	2009-04-27 19:31:00.000000000 +0300
+++ freehdl-0.0.8/freehdl/cdfggen-chunk.h	2020-03-30 02:54:42.423609306 +0300
@@ -7,7 +7,9 @@
 #include <string>
 #include <vector>
 typedef enum {to, downto} cdfgg_direction;
-using namespace std;
+using std::string;
+using std::vector;
+using std::pair;
 
 extern tree_chunk_info cdfggen_chunk_info;
 extern tree_ctype_info int_ctype_info;
diff -Nuar freehdl-0.0.8.orig/freehdl/cdfggen-chunk.t freehdl-0.0.8/freehdl/cdfggen-chunk.t
--- freehdl-0.0.8.orig/freehdl/cdfggen-chunk.t	2003-04-09 19:40:56.000000000 +0300
+++ freehdl-0.0.8/freehdl/cdfggen-chunk.t	2020-03-30 02:54:42.423609306 +0300
@@ -13,8 +13,7 @@
 (header-add "#include <freehdl/tree-supp.h>"
 	    "#include <string>"
 	    "#include <vector>"
-	    "typedef enum {to, downto} cdfgg_direction;"
-	    "using namespace std;")
+	    "typedef enum {to, downto} cdfgg_direction;")
 
 (impl-add "#include <freehdl/cdfggen-chunk.h>")
 
diff -Nuar freehdl-0.0.8.orig/freehdl/kernel-attributes.hh freehdl-0.0.8/freehdl/kernel-attributes.hh
--- freehdl-0.0.8.orig/freehdl/kernel-attributes.hh	2004-11-09 20:29:33.000000000 +0200
+++ freehdl-0.0.8/freehdl/kernel-attributes.hh	2020-03-30 02:54:42.423609306 +0300
@@ -1,6 +1,8 @@
 #ifndef FREEHDL_KERNEL_ATTRIBUTES_H
 #define FREEHDL_KERNEL_ATTRIBUTES_H
 
+using std::max;
+
 /* *************************************************************
  *  Function kind attributes for signals
  * ************************************************************* */
diff -Nuar freehdl-0.0.8.orig/freehdl/kernel-db.hh freehdl-0.0.8/freehdl/kernel-db.hh 
--- freehdl-0.0.8.orig/freehdl/kernel-db.hh	2009-03-15 19:51:51.000000000 +0200
+++ freehdl-0.0.8/freehdl/kernel-db.hh	2020-04-22 20:56:59.646330605 +0300
@@ -3,6 +3,11 @@
 
 #include <assert.h>
 
+#include <string>
+#include <vector>
+using std::string;
+using std::pair;
+using std::vector;
 
 /* This header file includes the definitions that are required to
  * setup a kernel database. This database will be used by the kernel
@@ -39,6 +44,11 @@
 
 define_db_entry_type(driver_data, driver_data_entry)
 
+#include <string>
+#include <vector>
+using std::string;
+using std::pair;
+using std::vector;
 
 // Now, create an database explorer instance. The database explorer is
 // used to search and manipulate the database. The explorer is
@@ -80,9 +90,11 @@
 #include <freehdl/kernel-util.hh>
 
 #if !defined __GNUC__ || __GNUC__ != 2
-#include <ext/hash_map>
+//#include <ext/hash_map>
+#include <unordered_map>
 #else
-#include <hash_map>
+//#include <hash_map>
+#include <unordered_map>
 #endif
 
 // Macro used to define a key type. K is the actual type of the key
@@ -254,10 +266,10 @@
 
 // A hash function template used tp generate a hash number from
 // d
-class db_basic_key_hash : public hash<unsigned long> {
+class db_basic_key_hash : public std::hash<unsigned long> {
 public:
   size_t operator()(const db_basic_key& x) const {
-    return (*(hash<unsigned long> *)this)(((unsigned long)x.value)>>2);
+    return (*(std::hash<unsigned long> *)this)(((unsigned long)x.value)>>2);
   }
 };
 
@@ -266,7 +278,8 @@
 class db : public db_base 
 {
   // This mappes is the actual database.
-  typedef hash_map<void*, db_key_entry_pair, db_basic_key_hash> db_data_map_type;
+  //typedef hash_map<void*, db_key_entry_pair, db_basic_key_hash> db_data_map_type;
+  typedef std::unordered_map<void*, db_key_entry_pair, db_basic_key_hash> db_data_map_type;
   db_data_map_type data_map;
 
   // The transaction id is incremented each time a new key is added or
diff -Nuar freehdl-0.0.8.orig/freehdl/kernel-dump.hh freehdl-0.0.8/freehdl/kernel-dump.hh
--- freehdl-0.0.8.orig/freehdl/kernel-dump.hh	2003-04-10 18:11:23.000000000 +0300
+++ freehdl-0.0.8/freehdl/kernel-dump.hh	2020-03-30 02:54:42.439609671 +0300
@@ -13,9 +13,9 @@
 #include <string>
 #include <fstream>
 
-using namespace std;
+using std::fstream;
 
-typedef map<string, char*, less<string> > Tmap;
+typedef map<string, const char*, less<string> > Tmap;
 extern Tmap mapping_translation_table;
 
 // For each signal which is dumped an virtual process is created. This
diff -Nuar freehdl-0.0.8.orig/freehdl/kernel-fhdl-stream.hh freehdl-0.0.8/freehdl/kernel-fhdl-stream.hh
--- freehdl-0.0.8.orig/freehdl/kernel-fhdl-stream.hh	2005-02-15 12:02:31.000000000 +0200
+++ freehdl-0.0.8/freehdl/kernel-fhdl-stream.hh	2020-03-30 02:54:42.439609671 +0300
@@ -9,7 +9,9 @@
 #include <string>
 #include <iostream>
 
-using namespace std;
+using std::istream;
+using std::ostream;
+using std::string;
 
 struct fhdl_ostream_t {
   union {
diff -Nuar freehdl-0.0.8.orig/freehdl/kernel-map-list.hh freehdl-0.0.8/freehdl/kernel-map-list.hh
--- freehdl-0.0.8.orig/freehdl/kernel-map-list.hh	2003-07-08 15:17:35.000000000 +0300
+++ freehdl-0.0.8/freehdl/kernel-map-list.hh	2020-03-30 02:54:42.439609671 +0300
@@ -7,7 +7,6 @@
 #include <freehdl/kernel-acl.hh>
 #include <freehdl/kernel-sig-info.hh>
 
-using namespace std;
 //using namespace __gnu_cxx;
 
 // A signal_link instance describes the connection
@@ -163,9 +162,11 @@
 #include <list>
 
 #if !defined __GNUC__ || __GNUC__ != 2
-#include <ext/hash_map>
+//#include <ext/hash_map>
+#include <unordered_map>
 #else
-#include <hash_map>
+//#include <hash_map>
+#include <unordered_map>
 #endif
 
 #include <freehdl/kernel-util.hh>
@@ -262,7 +263,7 @@
 };
 
 
-typedef hash_map<sig_info_base *, list<fl_link>, pointer_hash<sig_info_base *> > port_signal_link_map_t;
+typedef std::unordered_map<sig_info_base *, list<fl_link>, pointer_hash<sig_info_base *> > port_signal_link_map_t;
 
 // Stores the father signal(s) of port signals
 extern port_signal_link_map_t port_signal_link_map;
diff -Nuar freehdl-0.0.8.orig/freehdl/kernel-name-stack.hh freehdl-0.0.8/freehdl/kernel-name-stack.hh
--- freehdl-0.0.8.orig/freehdl/kernel-name-stack.hh	2003-04-09 19:10:06.000000000 +0300
+++ freehdl-0.0.8/freehdl/kernel-name-stack.hh	2020-03-30 02:54:42.439609671 +0300
@@ -3,7 +3,7 @@
 
 #include <string>
 
-using namespace std;
+using std::string;
 
 #define NAME_STACK_INCREMENT 10
 
diff -Nuar freehdl-0.0.8.orig/freehdl/kernel-signal-source-list-array.hh freehdl-0.0.8/freehdl/kernel-signal-source-list-array.hh
--- freehdl-0.0.8.orig/freehdl/kernel-signal-source-list-array.hh	2006-02-16 10:56:22.000000000 +0200
+++ freehdl-0.0.8/freehdl/kernel-signal-source-list-array.hh	2020-03-30 02:54:42.439609671 +0300
@@ -4,16 +4,17 @@
 #ifdef KERNEL
 
 #if !defined __GNUC__ || __GNUC__ != 2
-#include <ext/hash_map>
+//#include <ext/hash_map>
+#include <unordered_map>
 #else
-#include <hash_map>
+//#include <hash_map>
+#include <unordered_map>
 #endif
 
 #include <list>
 #include <freehdl/kernel-util.hh>
 #include <freehdl/kernel-source-descriptor.hh>
 
-using namespace std;
 //using namespace __gnu_cxx;
 
 // signal_source stores information about a source of a signal. Note
@@ -105,7 +106,7 @@
 // a map stores the sources for each signal. Note that each signal is
 // associated with a vector of signal_source_list pointers (included
 // in signal_source_list_array).
-typedef hash_map<sig_info_base *, signal_source_list_array, pointer_hash<sig_info_base *> > signal_source_map_t;
+typedef std::unordered_map<sig_info_base *, signal_source_list_array, pointer_hash<sig_info_base *> > signal_source_map_t;
 extern signal_source_map_t signal_source_map;
 
 #endif
diff -Nuar freehdl-0.0.8.orig/freehdl/kernel-util.hh freehdl-0.0.8/freehdl/kernel-util.hh 
--- freehdl-0.0.8.orig/freehdl/kernel-util.hh	2008-02-15 20:30:07.000000000 +0200
+++ freehdl-0.0.8/freehdl/kernel-util.hh	2020-04-22 20:36:48.558615436 +0300
@@ -10,24 +10,28 @@
 #include <string>
 
 #if !defined __GNUC__ || __GNUC__ != 2
-#include <ext/hash_map>
+//#include <ext/hash_map>
+#include <unordered_map>
 #else
-#include <hash_map>
+//#include <hash_map>
+#include <unordered_map>
 #endif
 
-using namespace std;
+using std::stringstream;
+using std::string;
+
 
 #if !defined __GNUC__ || __GNUC__ != 2
-using namespace __gnu_cxx;
+//using namespace __gnu_cxx;
 #endif
 
 // A hash function template used tp generate a hash number from
 // pointer values.
 template<class T>
-class pointer_hash : public hash<unsigned long> {
+class pointer_hash : public std::hash<unsigned long> {
 public:
   size_t operator()(const T& x) const {
-    return (*(hash<unsigned long> *)this)(((unsigned long)x)>>2);
+    return (*(std::hash<unsigned long> *)this)(((unsigned long)x)>>2);
   }
 };

diff -Nuar freehdl-0.0.8.orig/freehdl/std.h freehdl-0.0.8/freehdl/std.h
--- freehdl-0.0.8.orig/freehdl/std.h	2003-04-09 19:10:06.000000000 +0300
+++ freehdl-0.0.8/freehdl/std.h	2020-03-30 02:54:42.439609671 +0300
@@ -1,7 +1,6 @@
 #ifndef FREEHDL_STD_H
 #define FREEHDL_STD_H
 
-using namespace std;
 
 #include <freehdl/std-standard.hh>
 #include <freehdl/std-vhdl-types.hh>
diff -Nuar freehdl-0.0.8.orig/freehdl/std-vhdl-types.hh freehdl-0.0.8/freehdl/std-vhdl-types.hh
--- freehdl-0.0.8.orig/freehdl/std-vhdl-types.hh	2008-02-15 18:31:41.000000000 +0200
+++ freehdl-0.0.8/freehdl/std-vhdl-types.hh	2020-03-30 02:54:42.443609762 +0300
@@ -6,13 +6,24 @@
 #include <float.h>
 #include <math.h>
 #include <iostream>
+#include <map>
+#include <list>
+#include <functional>
 #include <string.h>
 
 #include <freehdl/std-memory.hh>
 #include <freehdl/kernel-error.hh>
 #include <freehdl/kernel-acl.hh>
 
-using namespace std;
+using std::string;
+using std::istream;
+using std::ostream;
+using std::min;
+using std::map;
+using std::stringstream;
+using std::list;
+using std::less;
+using std::iostream;
 
 typedef long long int lint;
 const int BUFFER_STREAM_SIZE_INCREMENT = 1024;
diff -Nuar freehdl-0.0.8.orig/freehdl/vaul-lexer.h freehdl-0.0.8/freehdl/vaul-lexer.h
--- freehdl-0.0.8.orig/freehdl/vaul-lexer.h	2009-04-21 22:37:36.000000000 +0300
+++ freehdl-0.0.8/freehdl/vaul-lexer.h	2020-03-30 02:54:42.443609762 +0300
@@ -32,7 +32,6 @@
 #include <stdarg.h>
 #include <string.h>
 
-using namespace std;
 
 #undef yyFlexLexer
 #define yyFlexLexer vaul_FlexLexer
diff -Nuar freehdl-0.0.8.orig/kernel/attributes.cc freehdl-0.0.8/kernel/attributes.cc
--- freehdl-0.0.8.orig/kernel/attributes.cc	2004-11-09 20:29:33.000000000 +0200
+++ freehdl-0.0.8/kernel/attributes.cc	2020-03-30 02:54:42.443609762 +0300
@@ -5,6 +5,7 @@
 #include <freehdl/kernel-kernel-class.hh>
 #include <freehdl/kernel-reader-info.hh>
 #include <freehdl/kernel-driver-info.hh>
+using std::max;
 #include <freehdl/kernel-attributes.hh>
 
 
diff -Nuar freehdl-0.0.8.orig/kernel/db.cc freehdl-0.0.8/kernel/db.cc
--- freehdl-0.0.8.orig/kernel/db.cc	2005-05-04 17:44:11.000000000 +0300
+++ freehdl-0.0.8/kernel/db.cc	2020-03-30 02:54:42.447609853 +0300
@@ -1,6 +1,5 @@
 #define KERNEL // Include internal kernel definitions
 
-using namespace std;
 #include <freehdl/kernel-db.hh>
 
 
diff -Nuar freehdl-0.0.8.orig/kernel/fhdl_stream.cc freehdl-0.0.8/kernel/fhdl_stream.cc
--- freehdl-0.0.8.orig/kernel/fhdl_stream.cc	2006-01-12 10:05:01.000000000 +0200
+++ freehdl-0.0.8/kernel/fhdl_stream.cc	2020-03-30 02:54:42.447609853 +0300
@@ -7,6 +7,9 @@
 #include <freehdl/kernel-error.hh>
 #include <freehdl/kernel-fhdl-stream.hh>
 
+using std::cin;
+using std::cout;
+using std::stringstream;
 
 // Error stream to output error messages generated by the kernel,
 // e.g. to print error messages due to invalid simulator commands
diff -Nuar freehdl-0.0.8.orig/kernel/kernel_class.cc freehdl-0.0.8/kernel/kernel_class.cc
--- freehdl-0.0.8.orig/kernel/kernel_class.cc	2009-10-11 19:34:19.000000000 +0300
+++ freehdl-0.0.8/kernel/kernel_class.cc	2020-03-30 02:54:42.447609853 +0300
@@ -15,6 +15,15 @@
 #include <freehdl/kernel-resolver-process.hh>
 #include <freehdl/kernel-resolver-descriptor.hh>
 #include <freehdl/kernel-fhdl-stream.hh>
+#include <algorithm>
+
+using std::cerr;
+using std::pair;
+using std::binary_function;
+
+using std::cerr;
+using std::pair;
+using std::binary_function;
 
 // Arguments that are passed in form the command line
 int main_argc;
@@ -678,7 +687,7 @@
   // list associated with the various reader infos. Identical lists
   // are replaced by appropriate pointers to a single list in order to
   // save memory.
-  typedef hash_multimap<unsigned int, reader_info *> wait_elements_map_t;
+  typedef std::unordered_multimap<unsigned int, reader_info *> wait_elements_map_t;
   wait_elements_map_t wait_elements_map;
 
   // Setup connection to the kernel data base
diff -Nuar freehdl-0.0.8.orig/kernel/main.cc freehdl-0.0.8/kernel/main.cc
--- freehdl-0.0.8.orig/kernel/main.cc	2009-03-15 20:48:13.000000000 +0200
+++ freehdl-0.0.8/kernel/main.cc	2020-03-30 02:54:42.447609853 +0300
@@ -34,6 +34,15 @@
 #include <freehdl/kernel-error.hh>
 #include <freehdl/kernel-fhdl-stream.hh>
 
+using std::ios;
+using std::ifstream;
+using std::ofstream;
+using std::ostringstream;
+using std::cin;
+using std::cerr;
+using std::cout;
+using std::endl;
+
 #ifdef PERFMON_STATISTICS
 #include "pcounter.hh"
 #endif
diff -Nuar freehdl-0.0.8.orig/kernel/map_list.cc freehdl-0.0.8/kernel/map_list.cc
--- freehdl-0.0.8.orig/kernel/map_list.cc	2006-02-16 10:56:22.000000000 +0200
+++ freehdl-0.0.8/kernel/map_list.cc	2020-03-30 02:54:42.447609853 +0300
@@ -3,6 +3,12 @@
 #include <freehdl/kernel-error.hh>
 #include <freehdl/kernel-sig-info.hh>
 #include <freehdl/kernel-resolver-descriptor.hh>
+#include <algorithm>
+
+
+using std::max;
+
+using std::max;
 
 // Stores the father signal(s) of port signals
 port_signal_link_map_t port_signal_link_map;
diff -Nuar freehdl-0.0.8.orig/kernel/name_stack.cc freehdl-0.0.8/kernel/name_stack.cc
--- freehdl-0.0.8.orig/kernel/name_stack.cc	2000-09-20 11:41:14.000000000 +0300
+++ freehdl-0.0.8/kernel/name_stack.cc	2020-03-30 02:54:42.447609853 +0300
@@ -1,8 +1,10 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <stack>
 #include <freehdl/kernel-error.hh>
 #include <freehdl/kernel-name-stack.hh>
 
+using std::stack;
 
 name_stack instance_name;
 
diff -Nuar freehdl-0.0.8.orig/kernel/persistent_cdfg_dump.cc freehdl-0.0.8/kernel/persistent_cdfg_dump.cc
--- freehdl-0.0.8.orig/kernel/persistent_cdfg_dump.cc	2006-02-16 10:56:22.000000000 +0200
+++ freehdl-0.0.8/kernel/persistent_cdfg_dump.cc	2020-03-30 02:54:42.447609853 +0300
@@ -3,6 +3,7 @@
 #include <freehdl/kernel-persistent-cdfg-dump.hh>
 #include <freehdl/kernel-persistent-dump.hh>
 
+using std::endl;
 
 buffer_stream register_cdfg_tmp_buffer;
 
diff -Nuar freehdl-0.0.8.orig/kernel/sig_info.cc freehdl-0.0.8/kernel/sig_info.cc
--- freehdl-0.0.8.orig/kernel/sig_info.cc	2009-03-15 20:23:09.000000000 +0200
+++ freehdl-0.0.8/kernel/sig_info.cc	2020-03-30 02:54:42.451609945 +0300
@@ -1,6 +1,5 @@
 #define KERNEL // Include internal kernel definitions
 
-using namespace std;
 #include <freehdl/kernel-error.hh>
 #include <freehdl/kernel-db.hh>
 #include <freehdl/kernel-sig-info.hh>
diff -Nuar freehdl-0.0.8.orig/std/internal_textio.cc freehdl-0.0.8/std/internal_textio.cc
--- freehdl-0.0.8.orig/std/internal_textio.cc	2006-01-26 09:41:24.000000000 +0200
+++ freehdl-0.0.8/std/internal_textio.cc	2020-03-30 02:54:42.451609945 +0300
@@ -10,6 +10,10 @@
 #include <freehdl/kernel-name-stack.hh>
 #include <freehdl/kernel-register.hh>
 
+using std::ios;
+using std::cin;
+using std::cout;
+
 /* package :std:textio */
 
 /* Definitions for access type :std:textio:line */
diff -Nuar freehdl-0.0.8.orig/std/vhdl_types.cc freehdl-0.0.8/std/vhdl_types.cc
--- freehdl-0.0.8.orig/std/vhdl_types.cc	2009-03-15 20:56:57.000000000 +0200
+++ freehdl-0.0.8/std/vhdl_types.cc	2020-03-30 02:54:42.451609945 +0300
@@ -12,6 +12,9 @@
 #include <freehdl/kernel-register.hh>
 
 
+using std::ios;
+using std::ifstream;
+using std::ofstream;
 
 /* *************************************************************
  *  Some global functions
diff -Nuar freehdl-0.0.8.orig/v2cc/mapping.cc freehdl-0.0.8/v2cc/mapping.cc
--- freehdl-0.0.8.orig/v2cc/mapping.cc	2008-02-15 20:11:15.000000000 +0200
+++ freehdl-0.0.8/v2cc/mapping.cc	2020-03-30 02:54:42.451609945 +0300
@@ -34,7 +34,12 @@
 #include <iostream>
 #include <stdlib.h>
 
-using namespace std;
+using std::string;
+using std::list;
+using std::map;
+using std::istream;
+using std::ifstream;
+using std::cerr;
 
 v2cc_mapper::v2cc_mapper ()
 {
diff -Nuar freehdl-0.0.8.orig/v2cc/v2cc.cc freehdl-0.0.8/v2cc/v2cc.cc
--- freehdl-0.0.8.orig/v2cc/v2cc.cc	2010-04-13 22:43:30.000000000 +0300
+++ freehdl-0.0.8/v2cc/v2cc.cc	2020-03-30 02:54:42.451609945 +0300
@@ -35,7 +35,6 @@
 
 */
 
-using namespace std;
 
 #if HAVE_MALLOC_H
 #include <malloc.h>
diff -Nuar freehdl-0.0.8.orig/v2cc/v2cc-const-fold.cc freehdl-0.0.8/v2cc/v2cc-const-fold.cc
--- freehdl-0.0.8.orig/v2cc/v2cc-const-fold.cc	2008-02-15 20:13:19.000000000 +0200
+++ freehdl-0.0.8/v2cc/v2cc-const-fold.cc	2020-03-30 02:54:42.451609945 +0300
@@ -16,6 +16,9 @@
 #include "v2cc-util.h"
 
 
+using std::cerr;
+using std::max;
+using std::min;
 
 // Used to generate error messages
 extern vaul_error_printer codegen_error;
diff -Nuar freehdl-0.0.8.orig/v2cc/v2cc-decl.cc freehdl-0.0.8/v2cc/v2cc-decl.cc
--- freehdl-0.0.8.orig/v2cc/v2cc-decl.cc	2010-05-08 15:15:38.000000000 +0300
+++ freehdl-0.0.8/v2cc/v2cc-decl.cc	2020-03-30 02:54:42.451609945 +0300
@@ -13,6 +13,9 @@
 #include "mapping.h"
 #include "v2cc-util.h"
 
+using std::endl;
+using std::min;
+using std::max;
 
 void test (RegionStack &rstack)
 {
diff -Nuar freehdl-0.0.8.orig/v2cc/v2cc-explore.cc freehdl-0.0.8/v2cc/v2cc-explore.cc
--- freehdl-0.0.8.orig/v2cc/v2cc-explore.cc	2010-04-12 21:40:40.000000000 +0300
+++ freehdl-0.0.8/v2cc/v2cc-explore.cc	2020-03-30 02:54:42.455610036 +0300
@@ -15,7 +15,6 @@
 #include "mapping.h"
 #include "v2cc-util.h"
 
-using namespace std;
 
 // Used to generate error messages
 extern vaul_error_printer codegen_error;
diff -Nuar freehdl-0.0.8.orig/v2cc/v2cc.h freehdl-0.0.8/v2cc/v2cc.h
--- freehdl-0.0.8.orig/v2cc/v2cc.h	2006-03-17 11:22:55.000000000 +0200
+++ freehdl-0.0.8/v2cc/v2cc.h	2020-03-30 02:54:42.463610219 +0300
@@ -1,7 +1,17 @@
 #ifndef V2CC_HEADER
 #define V2CC_HEADER
 
-using namespace std;
+using std::vector;
+using std::list;
+using std::string;
+using std::pair;
+using std::string;
+using std::set;
+using std::less;
+using std::deque;
+using std::binary_function;
+using std::map;
+using std::binary_function;
 
 #include <freehdl/vaul.h>
 #include "mapping.h"
diff -Nuar freehdl-0.0.8.orig/v2cc/v2cc-qid.cc freehdl-0.0.8/v2cc/v2cc-qid.cc
--- freehdl-0.0.8.orig/v2cc/v2cc-qid.cc	2006-02-16 10:56:22.000000000 +0200
+++ freehdl-0.0.8/v2cc/v2cc-qid.cc	2020-03-30 02:54:42.463610219 +0300
@@ -4,6 +4,7 @@
 #include "v2cc-util.h"
 
 
+using std::endl;
 
 // ******************************************************************************************
 // Name: m_qid , generic function
diff -Nuar freehdl-0.0.8.orig/v2cc/v2cc-util.cc freehdl-0.0.8/v2cc/v2cc-util.cc
--- freehdl-0.0.8.orig/v2cc/v2cc-util.cc	2009-04-19 01:51:38.000000000 +0300
+++ freehdl-0.0.8/v2cc/v2cc-util.cc	2020-03-30 02:54:42.463610219 +0300
@@ -9,6 +9,9 @@
 
 #include "v2cc-util.h"
 
+using std::endl;
+using std::hex;
+using std::dec;
 
 // ******************************************************************************************
 // Some global variables
diff -Nuar freehdl-0.0.8.orig/v2cc/v2cc-util.h freehdl-0.0.8/v2cc/v2cc-util.h
--- freehdl-0.0.8.orig/v2cc/v2cc-util.h	2007-10-23 23:13:29.000000000 +0300
+++ freehdl-0.0.8/v2cc/v2cc-util.h	2020-03-30 02:55:06.160150752 +0300
@@ -2,12 +2,19 @@
 #ifndef V2CC_UTIL_H 
 #define V2CC_UTIL_H
 
-using namespace std;
 
 #include <sstream>
 #include <iomanip>
 #include <freehdl/vaul.h>
 #include "v2cc-chunk.h"
+#include <type_traits>
+
+using std::stringstream;
+using std::setprecision;
+using std::showpoint;
+using std::ofstream;
+using std::cout;
+using std::to_string;
 
 // ******************************************************************************************
 // Some global variables
@@ -242,7 +249,8 @@
 
 /* Convert an integer value into a string */
 template <class T>
-inline string
+//inline string
+inline typename std::enable_if<!std::is_floating_point<T>::value, std::string>::type
 to_string(T i)
 {
   stringstream lstr;
@@ -250,6 +258,8 @@
   return lstr.str();
 }
 
+
+/*
 inline string
 to_string(double i)
 {
@@ -266,6 +276,7 @@
     return str + ".0";
 #endif
 }
+*/
 
 /* Print scalar value into a string */
 string
diff -Nuar freehdl-0.0.8.orig/vaul/bison-parser.cc freehdl-0.0.8/vaul/bison-parser.cc
--- freehdl-0.0.8.orig/vaul/bison-parser.cc	2009-10-11 19:24:48.000000000 +0300
+++ freehdl-0.0.8/vaul/bison-parser.cc	2020-03-30 02:54:42.467610310 +0300
@@ -86,7 +86,6 @@
 #include <malloc.h>
 #endif
 
-using namespace std;
 
 #define YYINITDEPTH 10000
 #define YYMAXDEPTH 100000
diff -Nuar freehdl-0.0.8.orig/vaul/bison-parser.yy freehdl-0.0.8/vaul/bison-parser.yy
--- freehdl-0.0.8.orig/vaul/bison-parser.yy	2006-02-16 10:56:23.000000000 +0200
+++ freehdl-0.0.8/vaul/bison-parser.yy	2020-03-30 02:54:42.471610401 +0300
@@ -49,7 +49,6 @@
 #include <malloc.h>
 #endif
 
-using namespace std;
 
 #define YYINITDEPTH 10000
 #define YYMAXDEPTH 100000
diff -Nuar freehdl-0.0.8.orig/vaul/printer.cc freehdl-0.0.8/vaul/printer.cc
--- freehdl-0.0.8.orig/vaul/printer.cc	2007-10-23 23:52:52.000000000 +0300
+++ freehdl-0.0.8/vaul/printer.cc	2020-03-30 02:54:42.471610401 +0300
@@ -27,7 +27,8 @@
 #include <string.h>
 #include <sstream>
 
-using namespace std;
+using std::ostringstream;
+using std::ostream;
 
 void vaul_printer::printf (const char *fmt, ...)
 {
diff -Nuar freehdl-0.0.8.orig/vaul/tree.cc freehdl-0.0.8/vaul/tree.cc
--- freehdl-0.0.8.orig/vaul/tree.cc	2005-02-28 19:40:13.000000000 +0200
+++ freehdl-0.0.8/vaul/tree.cc	2020-03-30 02:54:42.471610401 +0300
@@ -31,7 +31,7 @@
 #include <assert.h>
 #include <stdlib.h>
 
-using namespace std;
+using std::ostream;
 
 vaul_id_set::vaul_id_set(int dummy)
 {