Update README.md

README.md

@@ -1,12 +1,13 @@
 runkit\_object\_id (by the runkit7 project)
-======================================================
+===========================================
 
 For the safest function in [runkit(7)](https://github.com/runkit7/runkit7).
 This implements `runkit_object_id() : ?int`,
 which is similar to `spl_object_hash() : string`, but returns an integer instead of a string.
 The `runkit_object_id()` is faster if you need to take the ids of a large number of objects, and avoids the memory overhead of storing extra strings.
 
-[An integer id has been a requested function for a while, but doesn't seem like it will be added to the php standard libraries](https://bugs.php.net/bug.php?id=52657)
+Both `runkit_object_id($obj)` and `spl_object_hash($obj)` return identifiers that are unique **for the lifetime of the object**.
+After the object is garbage collected, that identifier can/will be used again.
 
 Supports php 5.3+ and php 7.0\+.
 
@@ -15,8 +16,13 @@ See [runkit\_object\_id-api.php](./runkit_object_id-api.php) for function stubs,
 [![Build Status](https://travis-ci.org/runkit7/runkit_object_id.svg?branch=master)](https://travis-ci.org/runkit7/runkit_object_id)
 [![Build Status (Windows)](https://ci.appveyor.com/api/projects/status/dmlr3sc8153n9cjv?svg=true)](https://ci.appveyor.com/project/TysonAndre/runkit-object-id)
 
+Motivation
+----------
+
+[An integer id has been a requested function for a while, but doesn't seem like it will be added to the php standard libraries](http://grokbase.com/t/php/php-internals/08chfwdavh/new-function-proposal-spl-object-id#2008121730trg75pyz8mn92dqwemjb14k8)
+
 Installation
-============
+------------
 
 Similar to [runkit7 installation steps](https://github.com/runkit7/runkit7#installation), but using this repo instead.