1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT LIBRARY COMPONENTS                          --
4--                                                                          --
5--    A D A . C O N T A I N E R S . I N D E F I N I T E _ H O L D E R S     --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 2011-2015, Free Software Foundation, Inc.         --
10--                                                                          --
11-- This specification is derived from the Ada Reference Manual for use with --
12-- GNAT. The copyright notice above, and the license provisions that follow --
13-- apply solely to the  contents of the part following the private keyword. --
14--                                                                          --
15-- GNAT is free software;  you can  redistribute it  and/or modify it under --
16-- terms of the  GNU General Public License as published  by the Free Soft- --
17-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
18-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
19-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
20-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
21--                                                                          --
22-- As a special exception under Section 7 of GPL version 3, you are granted --
23-- additional permissions described in the GCC Runtime Library Exception,   --
24-- version 3.1, as published by the Free Software Foundation.               --
25--                                                                          --
26-- You should have received a copy of the GNU General Public License and    --
27-- a copy of the GCC Runtime Library Exception along with this program;     --
28-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
29-- <http://www.gnu.org/licenses/>.                                          --
30------------------------------------------------------------------------------
31
32private with Ada.Finalization;
33private with Ada.Streams;
34
35generic
36   type Element_Type (<>) is private;
37   with function "=" (Left, Right : Element_Type) return Boolean is <>;
38
39package Ada.Containers.Indefinite_Holders is
40   pragma Annotate (CodePeer, Skip_Analysis);
41   pragma Preelaborate (Indefinite_Holders);
42   pragma Remote_Types (Indefinite_Holders);
43
44   type Holder is tagged private;
45   pragma Preelaborable_Initialization (Holder);
46
47   Empty_Holder : constant Holder;
48
49   function "=" (Left, Right : Holder) return Boolean;
50
51   function To_Holder (New_Item : Element_Type) return Holder;
52
53   function Is_Empty (Container : Holder) return Boolean;
54
55   procedure Clear (Container : in out Holder);
56
57   function Element (Container : Holder) return Element_Type;
58
59   procedure Replace_Element
60     (Container : in out Holder;
61      New_Item  : Element_Type);
62
63   procedure Query_Element
64     (Container : Holder;
65      Process   : not null access procedure (Element : Element_Type));
66
67   procedure Update_Element
68     (Container : in out Holder;
69      Process   : not null access procedure (Element : in out Element_Type));
70
71   type Constant_Reference_Type
72      (Element : not null access constant Element_Type) is private
73   with
74      Implicit_Dereference => Element;
75
76   type Reference_Type
77     (Element : not null access Element_Type) is private
78   with
79      Implicit_Dereference => Element;
80
81   function Constant_Reference
82     (Container : aliased Holder) return Constant_Reference_Type;
83   pragma Inline (Constant_Reference);
84
85   function Reference
86     (Container : aliased in out Holder) return Reference_Type;
87   pragma Inline (Reference);
88
89   procedure Assign (Target : in out Holder; Source : Holder);
90
91   function Copy (Source : Holder) return Holder;
92
93   procedure Move (Target : in out Holder; Source : in out Holder);
94
95private
96
97   use Ada.Finalization;
98   use Ada.Streams;
99
100   type Element_Access is access all Element_Type;
101
102   type Holder_Access is access all Holder;
103   for Holder_Access'Storage_Size use 0;
104
105   procedure Read
106     (Stream    : not null access Ada.Streams.Root_Stream_Type'Class;
107      Container : out Holder);
108
109   procedure Write
110     (Stream    : not null access Ada.Streams.Root_Stream_Type'Class;
111      Container : Holder);
112
113   type Holder is new Ada.Finalization.Controlled with record
114      Element : Element_Access;
115      Busy    : Natural := 0;
116   end record;
117   for Holder'Read use Read;
118   for Holder'Write use Write;
119
120   overriding procedure Adjust (Container : in out Holder);
121   overriding procedure Finalize (Container : in out Holder);
122
123   type Reference_Control_Type is new Controlled with
124   record
125      Container : Holder_Access;
126   end record;
127
128   overriding procedure Adjust (Control : in out Reference_Control_Type);
129   pragma Inline (Adjust);
130
131   overriding procedure Finalize (Control : in out Reference_Control_Type);
132   pragma Inline (Finalize);
133
134   type Constant_Reference_Type
135     (Element : not null access constant Element_Type) is
136      record
137         Control : Reference_Control_Type :=
138           raise Program_Error with "uninitialized reference";
139         --  The RM says, "The default initialization of an object of
140         --  type Constant_Reference_Type or Reference_Type propagates
141         --  Program_Error."
142      end record;
143
144   procedure Write
145     (Stream : not null access Root_Stream_Type'Class;
146      Item   : Constant_Reference_Type);
147
148   for Constant_Reference_Type'Write use Write;
149
150   procedure Read
151     (Stream : not null access Root_Stream_Type'Class;
152      Item   : out Constant_Reference_Type);
153
154   for Constant_Reference_Type'Read use Read;
155
156   type Reference_Type (Element : not null access Element_Type) is record
157      Control : Reference_Control_Type :=
158        raise Program_Error with "uninitialized reference";
159      --  The RM says, "The default initialization of an object of
160      --  type Constant_Reference_Type or Reference_Type propagates
161      --  Program_Error."
162   end record;
163
164   procedure Write
165     (Stream : not null access Root_Stream_Type'Class;
166      Item   : Reference_Type);
167
168   for Reference_Type'Write use Write;
169
170   procedure Read
171     (Stream : not null access Root_Stream_Type'Class;
172      Item   : out Reference_Type);
173
174   for Reference_Type'Read use Read;
175
176   Empty_Holder : constant Holder := (Controlled with null, 0);
177
178end Ada.Containers.Indefinite_Holders;
179