Add abstract streams module:

* New basic_abstract_ostream template for generic output * New abstract_ostream, common type alias * basic_scoped_ostream, RAII output to abstract streams
2025-11-27 22:45:52 +00:00 · 2014-03-01 09:56:32 -08:00
parent 8b659a6d32
commit d32b91e0de
6 changed files with 388 additions and 0 deletions
--- a/beast/streams/basic_abstract_ostream.h
+++ b/beast/streams/basic_abstract_ostream.h
@@ -0,0 +1,118 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_STREAMS_BASIC_ABSTRACT_OSTREAM_H_INCLUDED
+#define BEAST_STREAMS_BASIC_ABSTRACT_OSTREAM_H_INCLUDED
+
+#include "basic_scoped_ostream.h"
+
+#include <functional>
+#include <memory>
+#include <sstream>
+
+namespace beast {
+
+/** Abstraction for an output stream similar to std::basic_ostream. */
+template <
+    class CharT,
+    class Traits = std::char_traits <CharT>
+>
+class basic_abstract_ostream
+{
+public:
+    typedef std::basic_string <CharT, Traits> string_type;
+    typedef basic_scoped_ostream <CharT, Traits> scoped_stream_type;
+
+    basic_abstract_ostream() = default;
+
+    virtual
+    ~basic_abstract_ostream() = default;
+
+    basic_abstract_ostream (basic_abstract_ostream const&) = default;
+    basic_abstract_ostream& operator= (
+        basic_abstract_ostream const&) = default;
+
+    /** Returns `true` if the stream is active.
+        Inactive streams do not produce output.
+    */
+    /** @{ */
+    virtual
+    bool
+    active() const
+    {
+        return true;
+    }
+
+    explicit
+    operator bool() const
+    {
+        return active();
+    }
+    /** @} */
+
+    /** Returns a basic_scoped_ostream without appending anything.
+        This can be used if the caller wants to put the scoped stream
+        on the stack to build up output in a thread-safe fashion.
+    */
+#if 0
+    scoped_stream_type
+    scoped_stream ()
+    {
+#if 0
+        return scoped_stream_type (
+            [this](string_type const& s)
+            {
+                this->write (s);
+            });
+#else
+        return scoped_stream_type (*this);
+#endif
+    }
+#endif
+
+    /** Called to output each string. */
+    virtual
+    void
+    write (string_type const& s) = 0;
+
+    scoped_stream_type
+    operator<< (std::ostream& manip (std::ostream&))
+    {
+        return scoped_stream_type (manip,
+            [this](string_type const& s)
+            {
+                this->write (s);
+            });
+    }
+
+    template <class T>
+    scoped_stream_type
+    operator<< (T const& t)
+    {
+        return scoped_stream_type (t,
+            [this](string_type const& s)
+            {
+                this->write (s);
+            });
+    }
+};
+
+}
+
+#endif