[PATCH] [libstdc++] Add uniform container erasure.

[Jonathan Wakely]

On 30/04/15 07:33 -0400, Ed Smith-Rowland wrote:
>This has been in me tree for a good while.
>
>It is fairly simple and adds C++ experimental container erasure.

And make_array, which isn't in the working paper yet, so I'd prefer to
leave that part out for now.


>Index: include/experimental/erase_if.tcc
>===================================================================
>--- include/experimental/erase_if.tcc	(revision 0)
>+++ include/experimental/erase_if.tcc	(working copy)
>@@ -0,0 +1,70 @@
>+// <experimental/erase_if.tcc> -*- C++ -*-
>+
>+// Copyright (C) 2015 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.
>+
>+// Under Section 7 of GPL version 3, you are granted additional
>+// permissions described in the GCC Runtime Library Exception, version
>+// 3.1, as published by the Free Software Foundation.
>+
>+// You should have received a copy of the GNU General Public License and
>+// a copy of the GCC Runtime Library Exception along with this program;
>+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
>+// <http://www.gnu.org/licenses/>.
>+
>+/** @file experimental/erase_if.tcc
>+ *  This is an internal header file, included by other library headers.
>+ *  Do not attempt to use it directly. @headername{erase_if}

The Doxygen @headername command tells users which header they are
supposed to include, rather than this one. Since there is no
<erase_if> header that's wrong. I'd just omit the @headername.


>+ */
>+
>+#ifndef _GLIBCXX_EXPERIMENTAL_ERASE_IF_TCC
>+#define _GLIBCXX_EXPERIMENTAL_ERASE_IF_TCC 1
>+
>+#pragma GCC system_header
>+
>+#if __cplusplus <= 201103L
>+# include <bits/c++14_warning.h>
>+#else
>+
>+namespace std
>+{
>+namespace experimental
>+{
>+inline namespace fundamentals_v2
>+{
>+
>+  namespace __detail
>+  {
>+    template<typename _Container, typename _Predicate>
>+      void
>+      __erase_nodes_if(_Container& __cont, _Predicate __pred)
>+      {
>+	for (auto __iter = __cont.begin(), __last = __cont.end();
>+	     __iter != __last;)
>+	{
>+	  if (__pred(*__iter))
>+	    __iter = __cont.erase(__iter);
>+	  else
>+	    ++__iter;
>+	}
>+      }
>+  }

This file doesn't really seem like a .tcc to me, it isn't providing
definitions of templates declared elsewhere (specifically in an
erase_if.h header).

Maybe we want an experimental/bits/ directory for this sort of thing
(which I could also use for the filesystem headers I'm about to
commit) but in the meanwhile I think just experimental/erase_if.h is a
better name.


OK for trunk with those changes (remove make_array, rename erase_if.tcc)