File 0747-Clarify-that-digraphs-are-implemented-using-ETS-tabl.patch of Package erlang

From fb49944ed47c0aad24a1e6423ef6079a0281156d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 23 Aug 2019 11:54:30 +0200
Subject: [PATCH] Clarify that digraphs are implemented using ETS tables

https://bugs.erlang.org/browse/ERL-1032
---
 lib/stdlib/doc/src/digraph.xml | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/lib/stdlib/doc/src/digraph.xml b/lib/stdlib/doc/src/digraph.xml
index cf2c0844c9..fa6d2b81fe 100644
--- a/lib/stdlib/doc/src/digraph.xml
+++ b/lib/stdlib/doc/src/digraph.xml
@@ -36,10 +36,23 @@
   <modulesummary>Directed graphs.</modulesummary>
   <description>
     <p>This module provides a version of labeled
-      directed graphs. What makes the graphs provided here
-      non-proper directed graphs is that multiple edges between
-      vertices are allowed. However, the customary definition of
-      directed graphs is used here.</p>
+    directed graphs ("digraphs").</p>
+
+    <p>The digraphs managed by this module are stored in
+    <seealso marker="ets">ETS tables</seealso>.
+    That implies the following:</p>
+
+    <list type="bulleted">
+      <item><p>Only the process that created the digraph is allowed to update it.</p></item>
+      <item><p>Digraphs will not be garbage collected. The ETS tables used for a
+      digraph will only be deleted when <seealso marker="#delete/1"><c>delete/1</c></seealso>
+      is called or the process that created the digraph terminates.</p></item>
+      <item><p>A digraph is a mutable data structure.</p></item>
+    </list>
+      
+    <p>What makes the graphs provided here non-proper directed graphs
+    is that multiple edges between vertices are allowed. However, the
+    customary definition of directed graphs is used here.</p>
 
     <list type="bulleted">
       <item>
-- 
2.16.4