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, 7 insertions, 5 deletions

diff --git a/gcc/java/jcf-io.c b/gcc/java/jcf-io.c
index 97a3c0f..6a24f78 100644
--- a/gcc/java/jcf-io.c
+++ b/gcc/java/jcf-io.c
@@ -276,19 +276,21 @@ find_classfile (char *filename, JCF *jcf, const char *dep_name)
 
 struct charstar_hash : typed_noop_remove <char>
 {
-  typedef const char T;
-  static inline hashval_t hash (const T *candidate);
-  static inline bool equal (const T *existing, const T *candidate);
+  typedef const char value_type;
+  typedef const char compare_type;
+  static inline hashval_t hash (const value_type *candidate);
+  static inline bool equal (const value_type *existing,
+			    const compare_type *candidate);
 };
 
 inline hashval_t
-charstar_hash::hash (const T *candidate)
+charstar_hash::hash (const value_type *candidate)
 {
   return htab_hash_string (candidate);
 }
 
 inline bool
-charstar_hash::equal (const T *existing, const T *candidate)
+charstar_hash::equal (const value_type *existing, const compare_type *candidate)
 {
   return strcmp (existing, candidate) == 0;
 }