# HG changeset patch
# User Paul Eggert <eggert@cs.ucla.edu>
# Date 1423360962 28800
# Node ID 5aab9ce8ce71eb25b625d08f5a779ae70e412295
# Parent  bfac2afaac8b30d31858616adbbf1f0b3938d59e
diffseq: prefer ptrdiff_t to ssize_t

* lib/diffseq.h: In commentary, prefer ptrdiff_t to ssize_t.
ptrdiff_t is the natural type for signed indexes.
On a few older platforms, ssize_t is narrower than size_t.

diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2015-02-07  Paul Eggert  <eggert@cs.ucla.edu>
 
+	diffseq: prefer ptrdiff_t to ssize_t
+	* lib/diffseq.h: In commentary, prefer ptrdiff_t to ssize_t.
+	ptrdiff_t is the natural type for signed indexes.
+	On a few older platforms, ssize_t is narrower than size_t.
+
 	xalloc: fix typo that suppressed warnings
 	* lib/xalloc.h: Add missing _GL_INLINE_HEADER_END.
 	This typo, introduced a couple of years ago, mistakenly suppressed
diff --git a/lib/diffseq.h b/lib/diffseq.h
--- a/lib/diffseq.h
+++ b/lib/diffseq.h
@@ -41,8 +41,8 @@
      EQUAL                   A two-argument macro that tests two elements for
                              equality.
      OFFSET                  A signed integer type sufficient to hold the
-                             difference between two indices. Usually
-                             something like ssize_t.
+                             difference between two indices.  Usually
+                             something like ptrdiff_t.
      EXTRA_CONTEXT_FIELDS    Declarations of fields for 'struct context'.
      NOTE_DELETE(ctxt, xoff) Record the removal of the object xvec[xoff].
      NOTE_INSERT(ctxt, yoff) Record the insertion of the object yvec[yoff].