PR libstdc++/83134 Ensure std::__not_ converts B::value to bool

	PR libstdc++/83134
	* include/std/type_traits (__not_): Explicitly convert to bool.
	* testsuite/20_util/declval/requirements/1_neg.cc: Adjust dg-error.
	* testsuite/20_util/logical_traits/83134.cc: New test.
	* testsuite/20_util/make_signed/requirements/typedefs_neg.cc: Adjust
	dg-error.
	* testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc:
	Likewise.

From-SVN: r255122

libstdc++-v3/ChangeLog

+2017-11-23  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/83134
+	* include/std/type_traits (__not_): Explicitly convert to bool.
+	* testsuite/20_util/declval/requirements/1_neg.cc: Adjust dg-error.
+	* testsuite/20_util/logical_traits/83134.cc: New test.
+	* testsuite/20_util/make_signed/requirements/typedefs_neg.cc: Adjust
+	dg-error.
+	* testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc:
+	Likewise.
+
 2017-11-22  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR go/83102

libstdc++-v3/include/std/type_traits

@@ -151,10 +151,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   template<typename _Pp>
     struct __not_
-    : public integral_constant<bool, !_Pp::value>
+    : public __bool_constant<!bool(_Pp::value)>
     { };
 
-#if __cplusplus > 201402L
+#if __cplusplus >= 201703L
 
 #define __cpp_lib_logical_traits 201510
 
@@ -174,18 +174,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     { };
 
   template<typename... _Bn>
-    inline constexpr bool conjunction_v
-    = conjunction<_Bn...>::value;
+    inline constexpr bool conjunction_v = conjunction<_Bn...>::value;
 
   template<typename... _Bn>
-    inline constexpr bool disjunction_v
-    = disjunction<_Bn...>::value;
+    inline constexpr bool disjunction_v = disjunction<_Bn...>::value;
 
   template<typename _Pp>
-    inline constexpr bool negation_v
-    = negation<_Pp>::value;
+    inline constexpr bool negation_v = negation<_Pp>::value;
 
-#endif
+#endif // C++17
 
   // For several sfinae-friendly trait implementations we transport both the
   // result information (as the member type) and the failure information (no

libstdc++-v3/testsuite/20_util/declval/requirements/1_neg.cc

@@ -18,7 +18,7 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-error "static assertion failed" "" { target *-*-* } 2093 }
+// { dg-error "declval.. must not be used" "" { target *-*-* } 0 }
 
 #include <utility>
 

libstdc++-v3/testsuite/20_util/logical_traits/83134.cc

+// Copyright (C) 2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+#include <type_traits>
+
+struct X {
+  constexpr operator bool() const { return false; }
+  constexpr bool operator!() const = delete;
+};
+
+struct Y {
+  static constexpr X value{};
+};
+
+static_assert(std::negation<Y>::value);  // PR libstdc++/83134

libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs_neg.cc

@@ -47,4 +47,4 @@ void test01()
 // { dg-error "required from here" "" { target *-*-* } 39 }
 // { dg-error "required from here" "" { target *-*-* } 41 }
 
-// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1760 }
+// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1757 }

libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc

@@ -47,5 +47,5 @@ void test01()
 // { dg-error "required from here" "" { target *-*-* } 39 }
 // { dg-error "required from here" "" { target *-*-* } 41 }
 
-// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1656 }
+// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1653 }