C++11 has added new types (std::hash), which get dropped into the namespace due to
awful 'using namespace std;' declarations everywhere, causing name collisions.
Instead, only drop a minimal set of declarations into the global :: namespace.
See also: https://bugs.gentoo.org/show_bug.cgi?id=594706

--- a/fire/test-fire.cc
+++ b/fire/test-fire.cc
@@ -2,7 +2,7 @@
 #include <stdio.h>
 #include <freehdl/fire.h>
 
-using namespace std;
+using std::cout;
 
 extern tree_chunk_info fire_chunk_info;
 
--- a/freehdl/cdfggen-chunk.h
+++ b/freehdl/cdfggen-chunk.h
@@ -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;
--- a/freehdl/cdfggen-chunk.t
+++ b/freehdl/cdfggen-chunk.t
@@ -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>")
 
--- a/freehdl/kernel-attributes.hh
+++ b/freehdl/kernel-attributes.hh
@@ -1,6 +1,8 @@
 #ifndef FREEHDL_KERNEL_ATTRIBUTES_H
 #define FREEHDL_KERNEL_ATTRIBUTES_H
 
+using std::max;
+
 /* *************************************************************
  *  Function kind attributes for signals
  * ************************************************************* */
--- a/freehdl/kernel-db.hh
+++ b/freehdl/kernel-db.hh
@@ -3,6 +3,8 @@
 
 #include <assert.h>
 
+#include <string>
+using std::string;
 
 /* This header file includes the definitions that are required to
  * setup a kernel database. This database will be used by the kernel
@@ -254,7 +256,7 @@
 
 // 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 __gnu_cxx::hash<unsigned long> {
 public:
   size_t operator()(const db_basic_key& x) const {
     return (*(hash<unsigned long> *)this)(((unsigned long)x.value)>>2);
--- a/freehdl/kernel-dump.hh
+++ b/freehdl/kernel-dump.hh
@@ -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
--- a/freehdl/kernel-fhdl-stream.hh
+++ b/freehdl/kernel-fhdl-stream.hh
@@ -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 {
--- a/freehdl/kernel-map-list.hh
+++ b/freehdl/kernel-map-list.hh
@@ -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
--- a/freehdl/kernel-name-stack.hh
+++ b/freehdl/kernel-name-stack.hh
@@ -3,7 +3,7 @@
 
 #include <string>
 
-using namespace std;
+using std::string;
 
 #define NAME_STACK_INCREMENT 10
 
--- a/freehdl/kernel-signal-source-list-array.hh
+++ b/freehdl/kernel-signal-source-list-array.hh
@@ -13,7 +13,6 @@
 #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
--- a/freehdl/kernel-util.hh
+++ b/freehdl/kernel-util.hh
@@ -15,7 +15,8 @@
 #include <hash_map>
 #endif
 
-using namespace std;
+using std::stringstream;
+using std::string;
 
 #if !defined __GNUC__ || __GNUC__ != 2
 using namespace __gnu_cxx;
@@ -24,7 +25,7 @@
 // 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 __gnu_cxx::hash<unsigned long> {
 public:
   size_t operator()(const T& x) const {
     return (*(hash<unsigned long> *)this)(((unsigned long)x)>>2);
--- a/freehdl/std.h
+++ b/freehdl/std.h
@@ -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>
--- a/freehdl/std-vhdl-types.hh
+++ b/freehdl/std-vhdl-types.hh
@@ -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;
--- a/freehdl/vaul-lexer.h
+++ b/freehdl/vaul-lexer.h
@@ -32,7 +32,6 @@
 #include <stdarg.h>
 #include <string.h>
 
-using namespace std;
 
 #undef yyFlexLexer
 #define yyFlexLexer vaul_FlexLexer
--- a/ieee/numeric_std.cc
+++ b/ieee/numeric_std.cc
@@ -2,6 +2,7 @@
 #include <freehdl/std.h>
 
 
+using std::max;
 
 /* package :ieee:numeric_std */
 /* External declarations */
--- a/kernel/attributes.cc
+++ b/kernel/attributes.cc
@@ -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>
 
 
--- a/kernel/db.cc
+++ b/kernel/db.cc
@@ -1,6 +1,5 @@
 #define KERNEL // Include internal kernel definitions
 
-using namespace std;
 #include <freehdl/kernel-db.hh>
 
 
--- a/kernel/fhdl_stream.cc
+++ b/kernel/fhdl_stream.cc
@@ -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
--- a/kernel/kernel_class.cc
+++ b/kernel/kernel_class.cc
@@ -16,6 +16,10 @@
 #include <freehdl/kernel-resolver-descriptor.hh>
 #include <freehdl/kernel-fhdl-stream.hh>
 
+using std::cerr;
+using std::pair;
+using std::binary_function;
+
 // Arguments that are passed in form the command line
 int main_argc;
 char **main_argv;
--- a/kernel/main.cc
+++ b/kernel/main.cc
@@ -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
--- a/kernel/map_list.cc
+++ b/kernel/map_list.cc
@@ -4,6 +4,8 @@
 #include <freehdl/kernel-sig-info.hh>
 #include <freehdl/kernel-resolver-descriptor.hh>
 
+using std::max;
+
 // Stores the father signal(s) of port signals
 port_signal_link_map_t port_signal_link_map;
 
--- a/kernel/name_stack.cc
+++ b/kernel/name_stack.cc
@@ -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;
 
--- a/kernel/persistent_cdfg_dump.cc
+++ b/kernel/persistent_cdfg_dump.cc
@@ -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;
 
--- a/kernel/sig_info.cc
+++ b/kernel/sig_info.cc
@@ -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>
--- a/std/internal_textio.cc
+++ b/std/internal_textio.cc
@@ -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 */
--- a/std/vhdl_types.cc
+++ b/std/vhdl_types.cc
@@ -12,6 +12,9 @@
 #include <freehdl/kernel-register.hh>
 
 
+using std::ios;
+using std::ifstream;
+using std::ofstream;
 
 /* *************************************************************
  *  Some global functions
--- a/v2cc/mapping.cc
+++ b/v2cc/mapping.cc
@@ -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 ()
 {
--- a/v2cc/v2cc.cc
+++ b/v2cc/v2cc.cc
@@ -35,7 +35,6 @@
 
 */
 
-using namespace std;
 
 #if HAVE_MALLOC_H
 #include <malloc.h>
--- a/v2cc/v2cc-const-fold.cc
+++ b/v2cc/v2cc-const-fold.cc
@@ -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;
--- a/v2cc/v2cc-decl.cc
+++ b/v2cc/v2cc-decl.cc
@@ -13,6 +13,9 @@
 #include "mapping.h"
 #include "v2cc-util.h"
 
+using std::endl;
+using std::min;
+using std::max;
 
 void test (RegionStack &rstack)
 {
--- a/v2cc/v2cc-explore.cc
+++ b/v2cc/v2cc-explore.cc
@@ -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;
--- a/v2cc/v2cc.h
+++ b/v2cc/v2cc.h
@@ -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"
--- a/v2cc/v2cc-qid.cc
+++ b/v2cc/v2cc-qid.cc
@@ -4,6 +4,7 @@
 #include "v2cc-util.h"
 
 
+using std::endl;
 
 // ******************************************************************************************
 // Name: m_qid , generic function
--- a/v2cc/v2cc-util.cc
+++ b/v2cc/v2cc-util.cc
@@ -9,6 +9,9 @@
 
 #include "v2cc-util.h"
 
+using std::endl;
+using std::hex;
+using std::dec;
 
 // ******************************************************************************************
 // Some global variables
--- a/v2cc/v2cc-util.h
+++ b/v2cc/v2cc-util.h
@@ -2,13 +2,18 @@
 #ifndef V2CC_UTIL_H 
 #define V2CC_UTIL_H
 
-using namespace std;
 
 #include <sstream>
 #include <iomanip>
 #include <freehdl/vaul.h>
 #include "v2cc-chunk.h"
 
+using std::stringstream;
+using std::setprecision;
+using std::showpoint;
+using std::ofstream;
+using std::cout;
+
 // ******************************************************************************************
 // Some global variables
 // ******************************************************************************************
--- a/vaul/bison-parser.cc
+++ b/vaul/bison-parser.cc
@@ -86,7 +86,6 @@
 #include <malloc.h>
 #endif
 
-using namespace std;
 
 #define YYINITDEPTH 10000
 #define YYMAXDEPTH 100000
--- a/vaul/bison-parser.yy
+++ b/vaul/bison-parser.yy
@@ -49,7 +49,6 @@
 #include <malloc.h>
 #endif
 
-using namespace std;
 
 #define YYINITDEPTH 10000
 #define YYMAXDEPTH 100000
--- a/vaul/printer.cc
+++ b/vaul/printer.cc
@@ -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, ...)
 {
--- a/vaul/tree.cc
+++ b/vaul/tree.cc
@@ -31,7 +31,7 @@
 #include <assert.h>
 #include <stdlib.h>
 
-using namespace std;
+using std::ostream;
 
 vaul_id_set::vaul_id_set(int dummy)
 {