diff --git a/examples/termcap.cpp b/examples/termcap.cpp
index f93935f7..16554f20 100644
--- a/examples/termcap.cpp
+++ b/examples/termcap.cpp
@@ -230,10 +230,10 @@ void debug (const finalcut::FApplication& TermApp)
             << debug_data.getTermType_SecDA() << "\r\n";
 
   if ( ! ab_s.isEmpty() )
-    tcapString ("|         The answerback String", ab_s);
+    tcapString ("|         The answerback String", ab_s.c_str());
 
   if ( ! sec_da.isEmpty() )
-    tcapString ("|              The SecDA String", sec_da);
+    tcapString ("|              The SecDA String", sec_da.c_str());
 
   std::cout << "`------------------- debug -------------------\r\n";
 }
diff --git a/examples/ui.cpp b/examples/ui.cpp
index 6e429bac..66a324f1 100644
--- a/examples/ui.cpp
+++ b/examples/ui.cpp
@@ -1021,7 +1021,7 @@ void MyDialog::cb_view (const finalcut::FMenuItem* item)
   view->setResizeable();
   std::string line{""};
   std::ifstream infile;
-  infile.open(file);
+  infile.open(file.c_str());
 
   while ( ! infile.eof() && infile.good() )
   {
diff --git a/src/fapplication.cpp b/src/fapplication.cpp
index e2c80028..4de4859f 100644
--- a/src/fapplication.cpp
+++ b/src/fapplication.cpp
@@ -355,7 +355,7 @@ void FApplication::setDarkTheme()
 void FApplication::setLogFile (const FString& filename)
 {
   auto& log_stream = getStartOptions().logfile_stream;
-  log_stream.open(filename, std::ofstream::out);
+  log_stream.open(filename.c_str(), std::ofstream::out);
 
   if ( log_stream.is_open() )
   {
@@ -834,10 +834,8 @@ bool FApplication::processDialogSwitchAccelerator() const
 //----------------------------------------------------------------------
 bool FApplication::processAccelerator (const FWidget* const& widget) const
 {
-  bool accpt{false};
-
   if ( ! widget || widget->getAcceleratorList().empty() )
-    return accpt;
+    return false;
 
   for (auto&& item : widget->getAcceleratorList())
   {
@@ -854,15 +852,14 @@ bool FApplication::processAccelerator (const FWidget* const& widget) const
 
       FAccelEvent a_ev (fc::Accelerator_Event, getFocusWidget());
       sendEvent (item.object, &a_ev);
-      accpt = a_ev.isAccepted();
-      break;
+      return a_ev.isAccepted();
     }
 
     if ( quit_now || app_exit_loop )
       break;
   }
 
-  return accpt;
+  return false;
 }
 
 //----------------------------------------------------------------------
diff --git a/src/fbuttongroup.cpp b/src/fbuttongroup.cpp
index 0d9c3362..71571b1d 100644
--- a/src/fbuttongroup.cpp
+++ b/src/fbuttongroup.cpp
@@ -476,20 +476,15 @@ bool FButtonGroup::directFocusRadioButton() const
   if ( ! hasCheckedButton() || buttonlist.empty() )
     return false;
 
-  bool found_checked{false};
-
   for (auto&& item : buttonlist)
   {
     auto toggle_button = static_cast<FToggleButton*>(item);
 
     if ( toggle_button->isChecked() )
-    {
-      found_checked = directFocusCheckedRadioButton(toggle_button);
-      break;
-    }
+      return directFocusCheckedRadioButton (toggle_button);
   }
 
-  return found_checked;
+  return false;
 }
 
 //----------------------------------------------------------------------
diff --git a/src/ffiledialog.cpp b/src/ffiledialog.cpp
index 5b456fae..7e74f497 100644
--- a/src/ffiledialog.cpp
+++ b/src/ffiledialog.cpp
@@ -790,7 +790,7 @@ void FFileDialog::cb_processActivate()
                               return ! entry.name.empty()
                                   && input
                                   && ! input.isNull()
-                                  && std::strcmp(entry.name.c_str(), input) == 0
+                                  && std::strcmp(entry.name.c_str(), input.c_str()) == 0
                                   && entry.directory;
                             }
                           );
diff --git a/src/fstring.cpp b/src/fstring.cpp
index a28918eb..4dc74658 100644
--- a/src/fstring.cpp
+++ b/src/fstring.cpp
@@ -1534,76 +1534,6 @@ FString operator + (const FString& s1, const FString& s2)
   return tmp;
 }
 
-//----------------------------------------------------------------------
-FString operator + (const FString& s, const wchar_t c)
-{
-  FString tmp1{s};
-  wchar_t tmp2[2];
-  tmp2[0] = c;
-  tmp2[1] = L'\0';
-  tmp1._insert (tmp1.length, 1, tmp2);
-  return tmp1;
-}
-
-//----------------------------------------------------------------------
-FString operator + (const std::wstring& s1, const FString& s2)
-{
-  FString tmp{s1};
-  tmp._insert (tmp.length, s2.length, s2.wc_str());
-  return tmp;
-}
-
-//----------------------------------------------------------------------
-FString operator + (const wchar_t s1[], const FString& s2)
-{
-  FString tmp{s1};
-  tmp._insert (tmp.length, s2.length, s2.wc_str());
-  return tmp;
-}
-
-//----------------------------------------------------------------------
-FString operator + (const std::string& s1, const FString& s2)
-{
-  FString tmp{s1};
-  tmp._insert (tmp.length, s2.length, s2.wc_str());
-  return tmp;
-}
-
-//----------------------------------------------------------------------
-FString operator + (const char s1[], const FString& s2)
-{
-  FString tmp{s1};
-  tmp._insert (tmp.length, s2.length, s2.wc_str());
-  return tmp;
-}
-
-//----------------------------------------------------------------------
-FString operator + (const wchar_t c, const FString& s)
-{
-  FString tmp{c};
-  tmp._insert (1, s.length, s.wc_str());
-  return tmp;
-}
-
-//----------------------------------------------------------------------
-FString operator + (const char c, const FString& s)
-{
-  FString tmp{c};
-  tmp._insert (1, s.length, s.wc_str());
-  return tmp;
-}
-
-//----------------------------------------------------------------------
-FString operator + (const FString& s, const char c)
-{
-  FString tmp1{s};
-  wchar_t tmp2[2];
-  tmp2[0] = wchar_t(c & 0xff);
-  tmp2[1] = L'\0';
-  tmp1._insert (tmp1.length, 1, tmp2);
-  return tmp1;
-}
-
 //----------------------------------------------------------------------
 std::ostream& operator << (std::ostream& outstr, const FString& s)
 {
diff --git a/src/include/final/fstring.h b/src/include/final/fstring.h
index 8102d4cd..f5d02195 100644
--- a/src/include/final/fstring.h
+++ b/src/include/final/fstring.h
@@ -113,7 +113,10 @@ class FString
     FString& operator << (const char);
     template <typename NumT
             , typename std::enable_if< std::is_integral<NumT>::value
+                                    && ! std::is_same<NumT, bool>::value
+                                    && ! std::is_pointer<NumT>::value
                                     || std::is_floating_point<NumT>::value
+                                    && ! std::is_pointer<NumT>::value
                                      , int>::type = 0 >
     FString& operator << (const NumT);
 
@@ -157,8 +160,6 @@ class FString
     template <typename CharT>
     bool operator >  (const CharT&) const;
 
-    operator const char* () const { return c_str(); }
-
     // Accessor
     virtual FString getClassName() const;
 
@@ -263,14 +264,6 @@ class FString
 
     // Friend Non-member operator functions
     friend FString operator + (const FString&, const FString&);
-    friend FString operator + (const FString&, const wchar_t);
-    friend FString operator + (const std::wstring&, const FString&);
-    friend FString operator + (const wchar_t[], const FString&);
-    friend FString operator + (const std::string&, const FString&);
-    friend FString operator + (const char[], const FString&);
-    friend FString operator + (const wchar_t, const FString&);
-    friend FString operator + (const char, const FString&);
-    friend FString operator + (const FString&, const char);
 
     friend std::ostream&  operator << (std::ostream&, const FString&);
     friend std::istream&  operator >> (std::istream&, FString& s);
@@ -283,7 +276,10 @@ class FString
 //----------------------------------------------------------------------
 template <typename NumT
         , typename std::enable_if< std::is_integral<NumT>::value
+                                && ! std::is_same<NumT, bool>::value
+                                && ! std::is_pointer<NumT>::value
                                 || std::is_floating_point<NumT>::value
+                                && ! std::is_pointer<NumT>::value
                                  , int>::type >
 inline FString& FString::operator << (const NumT val)
 {
diff --git a/src/include/final/fstringstream.h b/src/include/final/fstringstream.h
index ce10acfb..bd4e9425 100644
--- a/src/include/final/fstringstream.h
+++ b/src/include/final/fstringstream.h
@@ -106,7 +106,7 @@ inline std::wstringbuf* FStringStream::rdbuf() const
 
 //----------------------------------------------------------------------
 inline FString FStringStream::str() const
-{ return buffer.str(); }
+{ return FString{buffer.str()}; }
 
 
 // FStringStream non-member function