Ada Programming/Libraries/Interfaces.C.Pointers

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This language feature is available from Ada 95 on.

Interfaces.C.Pointers is a unit of the Predefined Language Environment since Ada 95.

Specification

--                     Standard Ada library specification
--   Copyright (c) 2003-2018 Maxim Reznik <reznikmm@gmail.com>
--   Copyright (c) 2004-2016 AXE Consultants
--   Copyright (c) 2004, 2005, 2006 Ada-Europe
--   Copyright (c) 2000 The MITRE Corporation, Inc.
--   Copyright (c) 1992, 1993, 1994, 1995 Intermetrics, Inc.
--   SPDX-License-Identifier: BSD-3-Clause and LicenseRef-AdaReferenceManual
-- -------------------------------------------------------------------------

generic
   type Index is (<>);
   type Element is private;
   type Element_Array is array (Index range <>) of aliased Element;
   Default_Terminator : Element;
package Interfaces.C.Pointers is
   pragma Preelaborate (Pointers);

   type Pointer is access all Element;

   function Value (Ref        : in Pointer;
                   Terminator : in Element := Default_Terminator)
                  return Element_Array;

   function Value (Ref    : in Pointer;
                   Length : in ptrdiff_t)
                  return Element_Array;

   Pointer_Error : exception;

   --  C-style Pointer arithmetic

   function "+" (Left : in Pointer;   Right : in ptrdiff_t) return Pointer;
   function "+" (Left : in ptrdiff_t; Right : in Pointer)   return Pointer;
   function "-" (Left : in Pointer;   Right : in ptrdiff_t) return Pointer;
   function "-" (Left : in Pointer;   Right : in Pointer) return ptrdiff_t;

   procedure Increment (Ref : in out Pointer);
   procedure Decrement (Ref : in out Pointer);

   pragma Convention (Intrinsic, "+");
   pragma Convention (Intrinsic, "-");
   pragma Convention (Intrinsic, Increment);
   pragma Convention (Intrinsic, Decrement);

   function Virtual_Length (Ref        : in Pointer;
                            Terminator : in Element := Default_Terminator)
                           return ptrdiff_t;

   procedure Copy_Terminated_Array
     (Source     : in Pointer;
      Target     : in Pointer;
      Limit      : in ptrdiff_t := ptrdiff_t'Last;
      Terminator : in Element :=  Default_Terminator);

   procedure Copy_Array (Source  : in Pointer;
                         Target  : in Pointer;
                         Length  : in ptrdiff_t);

end Interfaces.C.Pointers;

See also

Wikibook

• Ada Programming/Libraries/Interfaces
• Ada Programming/Libraries/Interfaces.C

External examples

• Search for examples of Interfaces.C.Pointers in: Rosetta Code, GitHub (gists), any Alire crate or this Wikibook.
• Search for posts related to Interfaces.C.Pointers in: Stack Overflow, comp.lang.ada or any Ada related page.

Ada Reference Manual

Ada 95

• B.3.2: The Generic Package Interfaces.C.Pointers ^[Annotated]

Ada 2005

• B.3.2: The Generic Package Interfaces.C.Pointers ^[Annotated]

Ada 2012

• B.3.2: The Generic Package Interfaces.C.Pointers ^[Annotated]

Open-Source Implementations

FSF GNAT

• Specification: i-cpoint.ads
• Body: i-cpoint.adb

drake

• Specification: interfaces/i-cpoint.ads
• Body: interfaces/i-cpoint.adb