limits (numeric_limits): Fix returns per C++11.

2012-03-02  Paolo Carlini  <paolo.carlini@oracle.com>

	* include/std/limits (numeric_limits): Fix returns per C++11.
	* testsuite/18_support/numeric_limits/primary.cc: New.

From-SVN: r184837

libstdc++-v3/ChangeLog

@@ -1,3 +1,8 @@
+2012-03-02  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	* include/std/limits (numeric_limits): Fix returns per C++11.
+	* testsuite/18_support/numeric_limits/primary.cc: New.
+
 2012-03-02  Benjamin Kosnik  <bkoz@redhat.com>
 
 	* include/c_global/cstdio: Remove extraneous extern.

libstdc++-v3/include/std/limits

@@ -306,47 +306,47 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       /** The minimum finite value, or for floating types with
 	  denormalization, the minimum positive normalized value.  */
       static _GLIBCXX_CONSTEXPR _Tp
-      min() _GLIBCXX_USE_NOEXCEPT { return static_cast<_Tp>(0); }
+      min() _GLIBCXX_USE_NOEXCEPT { return _Tp(); }
 
       /** The maximum finite value.  */
       static _GLIBCXX_CONSTEXPR _Tp
-      max() _GLIBCXX_USE_NOEXCEPT { return static_cast<_Tp>(0); }
+      max() _GLIBCXX_USE_NOEXCEPT { return _Tp(); }
 
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
       /** A finite value x such that there is no other finite value y
        *  where y < x.  */
       static constexpr _Tp
-      lowest() noexcept { return static_cast<_Tp>(0); }
+      lowest() noexcept { return _Tp(); }
 #endif
 
       /** The @e machine @e epsilon:  the difference between 1 and the least
 	  value greater than 1 that is representable.  */
       static _GLIBCXX_CONSTEXPR _Tp
-      epsilon() _GLIBCXX_USE_NOEXCEPT { return static_cast<_Tp>(0); }
+      epsilon() _GLIBCXX_USE_NOEXCEPT { return _Tp(); }
 
       /** The maximum rounding error measurement (see LIA-1).  */
       static _GLIBCXX_CONSTEXPR _Tp
-      round_error() _GLIBCXX_USE_NOEXCEPT { return static_cast<_Tp>(0); }
+      round_error() _GLIBCXX_USE_NOEXCEPT { return _Tp(); }
 
       /** The representation of positive infinity, if @c has_infinity.  */
       static _GLIBCXX_CONSTEXPR _Tp
-      infinity() _GLIBCXX_USE_NOEXCEPT { return static_cast<_Tp>(0); }
+      infinity() _GLIBCXX_USE_NOEXCEPT { return _Tp(); }
 
       /** The representation of a quiet <em>Not a Number</em>,
 	  if @c has_quiet_NaN. */
       static _GLIBCXX_CONSTEXPR _Tp
-      quiet_NaN() _GLIBCXX_USE_NOEXCEPT { return static_cast<_Tp>(0); }
+      quiet_NaN() _GLIBCXX_USE_NOEXCEPT { return _Tp(); }
 
       /** The representation of a signaling <em>Not a Number</em>, if
 	  @c has_signaling_NaN. */
       static _GLIBCXX_CONSTEXPR _Tp
-      signaling_NaN() _GLIBCXX_USE_NOEXCEPT { return static_cast<_Tp>(0); }
+      signaling_NaN() _GLIBCXX_USE_NOEXCEPT { return _Tp(); }
 
       /** The minimum positive denormalized value.  For types where
 	  @c has_denorm is false, this is the minimum positive normalized
 	  value.  */
       static _GLIBCXX_CONSTEXPR _Tp
-      denorm_min() _GLIBCXX_USE_NOEXCEPT { return static_cast<_Tp>(0); }
+      denorm_min() _GLIBCXX_USE_NOEXCEPT { return _Tp(); }
     };
 
 #ifdef __GXX_EXPERIMENTAL_CXX0X__

libstdc++-v3/testsuite/18_support/numeric_limits/primary.cc

@@ -0,0 +1,24 @@
+// { dg-do compile }
+
+// Copyright (C) 2012 Free Software Foundation
+//
+// 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/>.
+
+#include <limits>
+
+struct MyBigNum { };
+
+template class std::numeric_limits<MyBigNum>;