From 7ce74ce206065c3af0035583330b3c773086f21c Mon Sep 17 00:00:00 2001
From: Karen Arutyunov <karen@codesynthesis.com>
Date: Thu, 3 Nov 2016 00:44:53 +0300
Subject: Invent auto_fd, make use of it in fdstreams and process

---
 butl/fdstream.ixx | 64 ++++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 44 insertions(+), 20 deletions(-)

(limited to 'butl/fdstream.ixx')

diff --git a/butl/fdstream.ixx b/butl/fdstream.ixx
index c7c329b..5d38d36 100644
--- a/butl/fdstream.ixx
+++ b/butl/fdstream.ixx
@@ -6,26 +6,51 @@
 
 namespace butl
 {
-  // ifdstream
+  // auto_fd
   //
-  inline ifdstream::
-  ifdstream ()
-      : std::istream (&buf_)
+  inline auto_fd& auto_fd::
+  operator= (auto_fd&& fd) noexcept
+  {
+    reset (fd.release ());
+    return *this;
+  }
+
+  inline int auto_fd::
+  release () noexcept
   {
-    exceptions (badbit | failbit);
+    int r (fd_);
+    fd_ = -1;
+    return r;
   }
 
+  inline void auto_fd::
+  reset (int fd) noexcept
+  {
+    if (fd_ >= 0)
+      fdclose (fd_); // Don't check for an error as not much we can do here.
+
+    fd_ = fd;
+  }
+
+  // ifdstream
+  //
   inline ifdstream::
-  ifdstream (int fd, iostate e)
-      : fdstream_base (fd), std::istream (&buf_)
+  ifdstream (auto_fd&& fd, iostate e)
+      : fdstream_base (std::move (fd)), std::istream (&buf_)
   {
     assert (e & badbit);
     exceptions (e);
   }
 
   inline ifdstream::
-  ifdstream (int fd, fdstream_mode m, iostate e)
-      : fdstream_base (fd, m),
+  ifdstream (iostate e)
+      : ifdstream (auto_fd (), e) // Delegate.
+  {
+  }
+
+  inline ifdstream::
+  ifdstream (auto_fd&& fd, fdstream_mode m, iostate e)
+      : fdstream_base (std::move (fd), m),
         std::istream (&buf_),
         skip_ ((m & fdstream_mode::skip) == fdstream_mode::skip)
   {
@@ -84,23 +109,22 @@ namespace butl
   // ofdstream
   //
   inline ofdstream::
-  ofdstream ()
-      : std::ostream (&buf_)
+  ofdstream (auto_fd&& fd, iostate e)
+      : fdstream_base (std::move (fd)), std::ostream (&buf_)
   {
-    exceptions (badbit | failbit);
+    assert (e & badbit);
+    exceptions (e);
   }
 
   inline ofdstream::
-  ofdstream (int fd, iostate e)
-      : fdstream_base (fd), std::ostream (&buf_)
+  ofdstream (iostate e)
+      : ofdstream (auto_fd (), e) // Delegate.
   {
-    assert (e & badbit);
-    exceptions (e);
   }
 
   inline ofdstream::
-  ofdstream (int fd, fdstream_mode m, iostate e)
-      : fdstream_base (fd, m), std::ostream (&buf_)
+  ofdstream (auto_fd&& fd, fdstream_mode m, iostate e)
+      : fdstream_base (std::move (fd), m), std::ostream (&buf_)
   {
     assert (e & badbit);
     exceptions (e);
@@ -156,13 +180,13 @@ namespace butl
 
   // fdopen()
   //
-  inline int
+  inline auto_fd
   fdopen (const std::string& f, fdopen_mode m, permissions p)
   {
     return fdopen (f.c_str (), m, p);
   }
 
-  inline int
+  inline auto_fd
   fdopen (const path& f, fdopen_mode m, permissions p)
   {
     return fdopen (f.string (), m, p);
-- 
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