# Ada Programming/Ada 2012

This is an overview of the major features that are available in Ada 2012.

## Summary of what's new
### New syntax

Added 4 forms of expressions:
* conditional expressions
* case expressions
* quantified expressions
* expression functions
These additional expressions originated with new support for contract based programming.

### New keywords

Added 1 keyword (73 total)
* some

### New pragmas

Added 5 pragmas:
* pragma CPU
* pragma Default_Storage_Pool
* pragma Dispatching_Domain
* pragma Independent
* pragma Independent_Components
Note that all these pragmas except Default_Storage_Pool born obsolescent, and it is recommended to use them as aspects instead.

### New aspects

Aspect specifications is a new feature of Ada 2012. While some aspect identifiers are completely new, others were present in previous versions of the language as aspect-related pragmas or attribute-definition clauses. Note that for these pragmas, in some cases the old pragma identifiers are marked as obsolescent, while in other cases the usage of the pragma is still the recommended approach.
Added 18 aspects:
* Constant_Indexing
* CPU (also added as an obsolescent pragma)
* Default_Component_Value
* Default_Iterator
* Default_Storage_Pool
* Default_Value
* Dispatching_Domain (also added as an obsolescent pragma)
* Dynamic_Predicate
* Implicit_Dereference
* Independent (also added as an obsolescent pragma)
* Independent_Components (also added as an obsolescent pragma)
* Iterator_Element
* Post
* Pre
* Static_Predicate
* Synchronization
* Type_Invariant
* Variable_Indexing
Aspect specifications already present in previous versions of the language as pragmas:
* All_Calls_Remote
* Asynchronous (pragma now obsolescent)
* Atomic (pragma now obsolescent)
* Atomic_Components (pragma now obsolescent)
* Attach_Handler (pragma now obsolescent)
* Convention (pragma now obsolescent)
* Elaborate_Body
* Export (pragma now obsolescent)
* External_Name
* External_Tag
* Import (pragma now obsolescent)
* Inline (pragma now obsolescent)
* Interrupt_Handler (pragma now obsolescent)
* Interrupt_Priority (pragma now obsolescent)
* Link_Name
* No_Return (pragma now obsolescent)
* Output
* Pack (pragma now obsolescent)
* Preelaborate
* Priority (pragma now obsolescent)
* Pure
* Relative_Deadline (pragma now obsolescent)
* Remote_Call_Interface
* Remote_Types
* Shared_Passive
* Storage_Size (pragma now obsolescent)
* Unchecked_Union (pragma now obsolescent)
* Volatile (pragma now obsolescent)
* Volatile_Components (pragma now obsolescent)
Aspect specifications already present in previous versions of the language as attribute definition clauses:
* Address
* Alignment
* Bit_Order
* Component_Size
* Input
* Machine_Radix
* Read
* Size
* Small
* Storage_Size
* Storage_Pool
* Stream_Size
* Write

### New attributes

Added 5 attributes:
* Has_Same_Storage
* Max_Alignment_For_Allocation
* Old
* Overlaps_Storage
* Result

### New packages

* Multiprocessing:
** System.Multiprocessors
** System.Multiprocessors.Dispatching_Domains
* Real-time:
** Ada.Execution_Time.Interrupts
* OS facilities:
** Ada.Directories.Hierarchical_File_Names
* Iterators:
** Ada.Iterator_Interfaces
* Text handling:
** Ada.Strings.UTF_Encoding
** Ada.Wide_Characters.Handling
** Ada.Wide_Wide_Characters.Handling
* Container library:
** Ada.Containers.Multiway_Trees
** Ada.Containers.Indefinite_Multiway_Trees
** Ada.Containers.Indefinite_Holders
** Ada.Containers.Bounded_Vectors
** Ada.Containers.Bounded_Doubly_Linked_Lists
** Ada.Containers.Bounded_Hashed_Maps
** Ada.Containers.Bounded_Ordered_Maps
** Ada.Containers.Bounded_Hashed_Sets
** Ada.Containers.Bounded_Ordered_Sets
** Ada.Containers.Bounded_Multiway_Trees
** Ada.Containers.Synchronized_Queue_Interfaces
** Ada.Containers.Unbounded_Synchronized_Queues
** Ada.Containers.Bounded_Synchronized_Queues
** Ada.Containers.Unbounded_Priority_Queues
** Ada.Containers.Bounded_Priority_Queues

## See also
### Wikibook

* Ada Programming/Ada 83
* Ada Programming/Ada 95
* Ada Programming/Ada 2005

### Pages in the category Ada 2012

* Category:Book:Ada Programming/Ada 2012 feature

## External links

* www.ada2012.org, website maintained by the Ada Resource Association.
* Ada Answers: Ada 2012
* ISO/IEC JTC1/SC22/WG9 N498 (2009). Instructions to the Ada Rapporteur Group from SC22/WG9 for Preparation of Amendment 2 to ISO/IEC 8652

### Papers and presentations

* Towards Ada 2012: an interim report from the Ada Rapporteur Group, by Ed Schonberg (2010-06-17)
* HD Video: An introduction to Ada 2012, presentation by Ed Schonberg (1h 02 min, 2012-10-16)

### Rationale

* Ada 2012 Rationale, by John Barnes
** Introduction
** Chapter 1: Contracts and Aspects
** Chapter 2: Expressions
** Chapter 3: Structure and Visibility
** Chapter 4: Tasking and Real-Time
** Chapter 5: Iterators, Pools, etc.
** Chapter 6: Containers
** Epilogue
** Predefined Library

### Ada Reference Manual

* Ada Reference Manual, ISO/IEC 8652:2012(E) — Language and Standard Libraries
** ISO/IEC 8652:2012 — Information technology — Programming languages — Ada (2012-12-10), same contents as the above link.
* Annotated Ada Reference Manual, ISO/IEC 8652:2012(E) — Language and Standard Libraries (colored diffs)
* List of Ada Amendment drafts

### Ada Issues

* Ada 2005 Issues
** AI05-0009-01 Confirming representation items and independence
** AI05-0145-02 Pre- and Postconditions
** AI05-0193-01 Alignment of allocators

### Implementations

* Implementation of Ada 2012 Features in GNAT compiler

### Press releases

* Ada 2012 Language Standard Approved by ISO, by Ada Resource Association & Ada-Europe (2012-12-18) PDF
* Ada 2012 Language Standard Submitted to ISO, by Ada Resource Association & Ada-Europe (2012-06-12) PDF