gdbsupport: remove gdb::optional

The previous patch migrated all the uses of gdb::optional to use
std::optional instead,  so gdb::optional can be removed entirely
as well as the self-tests which came with it.

Change-Id: I96ecd67b850b01be10ef00eb85a78ac647d5adc7
Approved-By: Tom Tromey <tom@tromey.com>
Approved-By: Pedro Alves <pedro@palves.net>

1 files changed, 0 insertions, 233 deletions

diff --git a/gdbsupport/gdb_optional.h b/gdbsupport/gdb_optional.h
deleted file mode 100644
index 9b7b7b2..0000000
--- a/gdbsupport/gdb_optional.h
+++ /dev/null
@@ -1,233 +0,0 @@
-/* An optional object.
-
-   Copyright (C) 2017-2023 Free Software Foundation, Inc.
-
-   This file is part of GDB.
-
-   This program 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 of the License, or
-   (at your option) any later version.
-
-   This program 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 program.  If not, see <http://www.gnu.org/licenses/>.  */
-
-#ifndef COMMON_GDB_OPTIONAL_H
-#define COMMON_GDB_OPTIONAL_H
-
-#include "gdbsupport/traits.h"
-
-namespace gdb
-{
-
-struct in_place_t
-{
-  explicit in_place_t () = default;
-};
-
-constexpr gdb::in_place_t in_place {};
-
-/* This class attempts to be a compatible subset of std::optional,
-   which is slated to be available in C++17.  This class optionally
-   holds an object of some type -- by default it is constructed not
-   holding an object, but later the object can be "emplaced".  This is
-   similar to using std::unique_ptr, but in-object allocation is
-   guaranteed.
-
-   Unlike std::optional, we currently only support copy/move
-   construction/assignment of an optional<T> from either exactly
-   optional<T> or T.  I.e., we don't support copy/move
-   construction/assignment from optional<U> or U, when U is a type
-   convertible to T.  Making that work depending on the definitions of
-   T and U is somewhat complicated, and currently the users of this
-   class don't need it.  */
-
-template<typename T>
-class optional
-{
-public:
-
-  constexpr optional ()
-    : m_dummy ()
-  {}
-
-  template<typename... Args>
-  constexpr optional (in_place_t, Args &&... args)
-    : m_item (std::forward<Args> (args)...),
-      m_instantiated (true)
-  {}
-
-  ~optional ()
-  { this->reset (); }
-
-  /* Copy and move constructors.  */
-
-  optional (const optional &other)
-  {
-    if (other.m_instantiated)
-      this->emplace (other.get ());
-  }
-
-  optional (optional &&other)
-    noexcept(std::is_nothrow_move_constructible<T> ())
-  {
-    if (other.m_instantiated)
-      this->emplace (std::move (other.get ()));
-  }
-
-  constexpr optional (const T &other)
-    : m_item (other),
-      m_instantiated (true)
-  {}
-
-  constexpr optional (T &&other)
-    noexcept (std::is_nothrow_move_constructible<T> ())
-    : m_item (std::move (other)),
-      m_instantiated (true)
-  {}
-
-  /* Assignment operators.  */
-
-  optional &
-  operator= (const optional &other)
-  {
-    if (m_instantiated && other.m_instantiated)
-      this->get () = other.get ();
-    else
-      {
-	if (other.m_instantiated)
-	  this->emplace (other.get ());
-	else
-	  this->reset ();
-      }
-
-    return *this;
-  }
-
-  optional &
-  operator= (optional &&other)
-    noexcept (And<std::is_nothrow_move_constructible<T>,
-	      std::is_nothrow_move_assignable<T>> ())
-  {
-    if (m_instantiated && other.m_instantiated)
-      this->get () = std::move (other.get ());
-    else
-      {
-	if (other.m_instantiated)
-	  this->emplace (std::move (other.get ()));
-	else
-	  this->reset ();
-      }
-    return *this;
-  }
-
-  optional &
-  operator= (const T &other)
-  {
-    if (m_instantiated)
-      this->get () = other;
-    else
-      this->emplace (other);
-    return *this;
-  }
-
-  optional &
-  operator= (T &&other)
-    noexcept (And<std::is_nothrow_move_constructible<T>,
-	      std::is_nothrow_move_assignable<T>> ())
-  {
-    if (m_instantiated)
-      this->get () = std::move (other);
-    else
-      this->emplace (std::move (other));
-    return *this;
-  }
-
-  template<typename... Args>
-  T &emplace (Args &&... args)
-  {
-    this->reset ();
-    new (&m_item) T (std::forward<Args>(args)...);
-    m_instantiated = true;
-    return this->get ();
-  }
-
-  /* Observers.  */
-  constexpr const T *operator-> () const
-  { return std::addressof (this->get ()); }
-
-  T *operator-> ()
-  { return std::addressof (this->get ()); }
-
-  constexpr const T &operator* () const &
-  { return this->get (); }
-
-  T &operator* () &
-  { return this->get (); }
-
-  T &&operator* () &&
-  { return std::move (this->get ()); }
-
-  constexpr const T &&operator* () const &&
-  { return std::move (this->get ()); }
-
-  constexpr explicit operator bool () const noexcept
-  { return m_instantiated; }
-
-  constexpr bool has_value () const noexcept
-  { return m_instantiated; }
-
-  /* 'reset' is a 'safe' operation with no precondition.  */
-  void reset () noexcept
-  {
-    if (m_instantiated)
-      this->destroy ();
-  }
-
-private:
-
-  /* Destroy the object.  */
-  void destroy ()
-  {
-    gdb_assert (m_instantiated);
-    m_instantiated = false;
-    m_item.~T ();
-  }
-
-  /* The get operations have m_instantiated as a precondition.  */
-  T &get () noexcept
-  {
-#if defined(_GLIBCXX_DEBUG) && __cplusplus >= 201402L
-    gdb_assert (this->has_value ());
-#endif
-    return m_item;
-  }
-  constexpr const T &get () const noexcept
-  {
-#if defined(_GLIBCXX_DEBUG) && __cplusplus >= 201402L
-    gdb_assert (this->has_value ());
-#endif
-    return m_item;
-  }
-
-  /* The object.  */
-  union
-  {
-    struct { } m_dummy;
-    T m_item;
-    volatile char dont_use; /* Silences -Wmaybe-uninitialized warning, see
-			       PR gcc/80635.  */
-  };
-
-  /* True if the object was ever emplaced.  */
-  bool m_instantiated = false;
-};
-
-}
-
-#endif /* COMMON_GDB_OPTIONAL_H */