Extend valid values of iostream bitmask types

	PR libstdc++/56158
	* include/bits/ios_base.h (_Ios_Fmtflags, _Ios_Openmode, _Ios_Iostate):
	Define enumerators to ensure all values of type int are valid values
	of the enumeration type.
	* testsuite/27_io/ios_base/types/fmtflags/case_label.cc: Add new cases.
	* testsuite/27_io/ios_base/types/iostate/case_label.cc: Likewise.
	* testsuite/27_io/ios_base/types/openmode/case_label.cc: Likewise.

From-SVN: r230267

libstdc++-v3/ChangeLog

 2015-11-12  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/56158
+	* include/bits/ios_base.h (_Ios_Fmtflags, _Ios_Openmode, _Ios_Iostate):
+	Define enumerators to ensure all values of type int are valid values
+	of the enumeration type.
+	* testsuite/27_io/ios_base/types/fmtflags/case_label.cc: Add new cases.
+	* testsuite/27_io/ios_base/types/iostate/case_label.cc: Likewise.
+	* testsuite/27_io/ios_base/types/openmode/case_label.cc: Likewise.
+
 	* include/std/thread: Include <cerrno> for EINTR.
 
 2015-11-12  Ville Voutilainen  <ville.voutilainen@gmail.com>

libstdc++-v3/include/bits/ios_base.h

@@ -74,7 +74,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _S_adjustfield 	= _S_left | _S_right | _S_internal,
       _S_basefield 	= _S_dec | _S_oct | _S_hex,
       _S_floatfield 	= _S_scientific | _S_fixed,
-      _S_ios_fmtflags_end = 1L << 16 
+      _S_ios_fmtflags_end = 1L << 16,
+      _S_ios_fmtflags_max = __INT_MAX__,
+      _S_ios_fmtflags_min = ~__INT_MAX__
     };
 
   inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
@@ -114,7 +116,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _S_in 		= 1L << 3,
       _S_out 		= 1L << 4,
       _S_trunc 		= 1L << 5,
-      _S_ios_openmode_end = 1L << 16 
+      _S_ios_openmode_end = 1L << 16,
+      _S_ios_openmode_max = __INT_MAX__,
+      _S_ios_openmode_min = ~__INT_MAX__
     };
 
   inline _GLIBCXX_CONSTEXPR _Ios_Openmode
@@ -152,7 +156,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _S_badbit 		= 1L << 0,
       _S_eofbit 		= 1L << 1,
       _S_failbit		= 1L << 2,
-      _S_ios_iostate_end = 1L << 16 
+      _S_ios_iostate_end = 1L << 16,
+      _S_ios_iostate_max = __INT_MAX__,
+      _S_ios_iostate_min = ~__INT_MAX__
     };
 
   inline _GLIBCXX_CONSTEXPR _Ios_Iostate

libstdc++-v3/testsuite/27_io/ios_base/types/fmtflags/case_label.cc

@@ -70,5 +70,9 @@ case_labels(bitmask_type b)
       break;
     case std::_S_ios_fmtflags_end:
       break;
+    case std::_S_ios_fmtflags_min:
+      break;
+    case std::_S_ios_fmtflags_max:
+      break;
     }
 }

libstdc++-v3/testsuite/27_io/ios_base/types/iostate/case_label.cc

@@ -42,5 +42,9 @@ case_labels(bitmask_type b)
       break;
     case std::_S_ios_iostate_end:
       break;
+    case std::_S_ios_iostate_min:
+      break;
+    case std::_S_ios_iostate_max:
+      break;
     }
 }

libstdc++-v3/testsuite/27_io/ios_base/types/openmode/case_label.cc

@@ -46,5 +46,9 @@ case_labels(bitmask_type b)
       break;
     case std::_S_ios_openmode_end:
       break;
+    case std::_S_ios_openmode_min:
+      break;
+    case std::_S_ios_openmode_max:
+      break;
     }
 }