Change hash_table to support a comparator type different from the value type stored in the hash table.

Change hash_table to support a comparator type different from the
value type stored in the hash table.  The 'find' functions now may
take a different type from the value type.  This requires introducing
a second typedef into the Descriptor conceptual type.  Change the
Descriptor concept to use typedefs value_type and compare_type instead
of T.  Change all users to match.

Add usage documentation to hash-table.h.

Tested on x86-64.


Index: gcc/ChangeLog

2012-10-25  Lawrence Crowl  <crowl@google.com>

	* hash-table.h: Add usage documentation.
	(template struct typed_free_remove): Clarify documentation. 
	Rename template parameter.
	(struct typed_noop_remove): Likewise.
	(descriptor concept): Change typedef T to value_type.
	Add typedef compare_type.  Use more precise template parameter name,
	Descriptor instead of Descr.  Update users to match.
	(struct hash_table): Change 'find' parameters to use compare_type
	instead of the value type.

From-SVN: r192823

1 files changed, 6 insertions, 5 deletions

diff --git a/gcc/tree-ssa-threadupdate.c b/gcc/tree-ssa-threadupdate.c
index ad64876..eca88a9 100644
--- a/gcc/tree-ssa-threadupdate.c
+++ b/gcc/tree-ssa-threadupdate.c
@@ -127,20 +127,21 @@ struct redirection_data : typed_free_remove<redirection_data>
   struct el *incoming_edges;
 
   /* hash_table support.  */
-  typedef redirection_data T;
-  static inline hashval_t hash (const redirection_data *);
-  static inline int equal (const redirection_data *, const redirection_data *);
+  typedef redirection_data value_type;
+  typedef redirection_data compare_type;
+  static inline hashval_t hash (const value_type *);
+  static inline int equal (const value_type *, const compare_type *);
 };
 
 inline hashval_t
-redirection_data::hash (const redirection_data *p)
+redirection_data::hash (const value_type *p)
 {
   edge e = p->outgoing_edge;
   return e->dest->index;
 }
 
 inline int
-redirection_data::equal (const redirection_data *p1, const redirection_data *p2)
+redirection_data::equal (const value_type *p1, const compare_type *p2)
 {
   edge e1 = p1->outgoing_edge;
   edge e2 = p2->outgoing_edge;