[libsigc++2] Don't use SIGC_USING_STD()

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 260d2fd74c39e9ca1541eb0ffd13ea315e6d16cf
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Thu Dec 17 15:17:12 2015 +0100

    Don't use SIGC_USING_STD()
    
    The SIGC_USING_STD() macro is defined as an empty string, if some standard
    C++ symbols are defined in namespace std. They always are.
    Since many years, SIGC_USING_STD() is an unnecessary macro.

 examples/hello_world.cc   |    4 ----
 examples/member_method.cc |    4 ----
 sigc++/connection.cc      |    1 -
 sigc++/trackable.cc       |    5 -----
 tests/test_disconnect.cc  |    1 -
 tests/test_slot.cc        |    2 --
 tests/test_slot_move.cc   |    1 -
 7 files changed, 0 insertions(+), 18 deletions(-)
---
diff --git a/examples/hello_world.cc b/examples/hello_world.cc
index 5371872..aff82f2 100644
--- a/examples/hello_world.cc
+++ b/examples/hello_world.cc
@@ -9,10 +9,6 @@
 
 #include <sigc++/sigc++.h>
 
-SIGC_USING_STD(cout)
-SIGC_USING_STD(endl)
-SIGC_USING_STD(string)
-
 void on_print(const std::string& str)
 {
   std::cout << str;
diff --git a/examples/member_method.cc b/examples/member_method.cc
index 6564ba9..574b1fc 100644
--- a/examples/member_method.cc
+++ b/examples/member_method.cc
@@ -9,10 +9,6 @@
 
 #include <sigc++/sigc++.h>
 
-SIGC_USING_STD(cout)
-SIGC_USING_STD(endl)
-SIGC_USING_STD(string)
-
 class Something : public sigc::trackable
 {
 public:
diff --git a/sigc++/connection.cc b/sigc++/connection.cc
index 91ee4ee..0d1d52e 100644
--- a/sigc++/connection.cc
+++ b/sigc++/connection.cc
@@ -18,7 +18,6 @@
  */
 
 #include <sigc++/connection.h>
-using namespace std;
 
 namespace sigc {
 
diff --git a/sigc++/trackable.cc b/sigc++/trackable.cc
index f7ac08d..135d1ca 100644
--- a/sigc++/trackable.cc
+++ b/sigc++/trackable.cc
@@ -18,11 +18,6 @@
  */
 
 #include <sigc++/trackable.h>
-#include <iostream>
-
-SIGC_USING_STD(ostream)
-
-using namespace std;
 
 namespace sigc
 {
diff --git a/tests/test_disconnect.cc b/tests/test_disconnect.cc
index 53e081a..048acbd 100644
--- a/tests/test_disconnect.cc
+++ b/tests/test_disconnect.cc
@@ -15,7 +15,6 @@
 //The Tru64 compiler seems to need this to avoid an unresolved symbol
 //See bug #161503
 #include <new>
-SIGC_USING_STD(new)
 
 namespace
 {
diff --git a/tests/test_slot.cc b/tests/test_slot.cc
index 05df99a..07b3580 100644
--- a/tests/test_slot.cc
+++ b/tests/test_slot.cc
@@ -1,4 +1,3 @@
-// -*- c++ -*-
 /* Copyright 2002, The libsigc++ Development Team
  *  Assigned to public domain.  Use as you wish without restriction.
  */
@@ -12,7 +11,6 @@
 //The Tru64 compiler seems to need this to avoid an unresolved symbol
 //See bug #161503
 #include <new>
-SIGC_USING_STD(new)
 
 namespace
 {
diff --git a/tests/test_slot_move.cc b/tests/test_slot_move.cc
index c479da1..06975f5 100644
--- a/tests/test_slot_move.cc
+++ b/tests/test_slot_move.cc
@@ -11,7 +11,6 @@
 //The Tru64 compiler seems to need this to avoid an unresolved symbol
 //See bug #161503
 #include <new>
-SIGC_USING_STD(new)
 
 namespace
 {