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Diffstat (limited to 'gcc-4.7/gcc/ada/s-strhas.ads')
| -rw-r--r-- | gcc-4.7/gcc/ada/s-strhas.ads | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/gcc-4.7/gcc/ada/s-strhas.ads b/gcc-4.7/gcc/ada/s-strhas.ads new file mode 100644 index 000000000..c2e72ccbb --- /dev/null +++ b/gcc-4.7/gcc/ada/s-strhas.ads @@ -0,0 +1,60 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S Y S T E M . S T R I N G _ H A S H -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2009, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This package provides a generic hashing function over strings, suitable for +-- use with a string keyed hash table. In particular, it is the basis for the +-- string hash functions in Ada.Containers. +-- +-- The algorithm used here is not appropriate for applications that require +-- cryptographically strong hashes, or for application which wish to use very +-- wide hash values as pseudo unique identifiers. In such cases please refer +-- to GNAT.SHA1 and GNAT.MD5. + +package System.String_Hash is + pragma Pure; + + generic + type Char_Type is (<>); + -- The character type composing the key string type + + type Key_Type is array (Positive range <>) of Char_Type; + -- The string type to use as a hash key + + type Hash_Type is mod <>; + -- The type to be returned as a hash value. This must be a 32-bit + -- unsigned type with full range 0 .. 2**32-1, no other type is allowed + -- for this instantiation (checked in the body by Compile_Time_Error). + + function Hash (Key : Key_Type) return Hash_Type; + pragma Inline (Hash); + -- Compute a hash value for a key + +end System.String_Hash; |