File : a-coboho.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT LIBRARY COMPONENTS --
4 -- --
5 -- A D A . C O N T A I N E R S . B O U N D E D _ H O L D E R S --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 2015, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
17 -- --
18 -- --
19 -- --
20 -- --
21 -- --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
26 ------------------------------------------------------------------------------
27
28 with Unchecked_Conversion;
29
30 package body Ada.Containers.Bounded_Holders is
31
32 function Size_In_Storage_Elements (Element : Element_Type) return Natural;
33 -- This returns the size of Element in storage units. It raises an
34 -- exception if the size is not a multiple of Storage_Unit, or if the size
35 -- is too big.
36
37 ------------------------------
38 -- Size_In_Storage_Elements --
39 ------------------------------
40
41 function Size_In_Storage_Elements (Element : Element_Type) return Natural is
42 Max_Size : Natural renames Max_Size_In_Storage_Elements;
43
44 begin
45 return S : constant Natural := Element'Size / System.Storage_Unit do
46 pragma Assert
47 (Element'Size mod System.Storage_Unit = 0,
48 "Size must be a multiple of Storage_Unit");
49
50 pragma Assert
51 (S <= Max_Size, "Size is too big:" & S'Img & " >" & Max_Size'Img);
52 end return;
53 end Size_In_Storage_Elements;
54
55 function Cast is new
56 Unchecked_Conversion (System.Address, Element_Access);
57
58 ---------
59 -- "=" --
60 ---------
61
62 function "=" (Left, Right : Holder) return Boolean is
63 begin
64 return Get (Left) = Get (Right);
65 end "=";
66
67 -------------
68 -- Element --
69 -------------
70
71 function Get (Container : Holder) return Element_Type is
72 begin
73 return Cast (Container'Address).all;
74 end Get;
75
76 ---------
77 -- Set --
78 ---------
79
80 procedure Set (Container : in out Holder; New_Item : Element_Type) is
81 Storage : Storage_Array
82 (1 .. Size_In_Storage_Elements (New_Item)) with
83 Address => New_Item'Address;
84 begin
85 Container.Data (Storage'Range) := Storage;
86 end Set;
87
88 ---------------
89 -- To_Holder --
90 ---------------
91
92 function To_Holder (New_Item : Element_Type) return Holder is
93 begin
94 return Result : Holder do
95 Set (Result, New_Item);
96 end return;
97 end To_Holder;
98
99 end Ada.Containers.Bounded_Holders;