From 0a71e4f02aaf5e319c8dac26311b9b46d4764ef4 Mon Sep 17 00:00:00 2001
From: Ruyman Reyes <ruyman@codeplay.com>
Date: Mon, 10 Jul 2017 10:46:19 +0100
Subject: [PATCH 1/2] Placeholder accessors can be default constructed

* Placeholder accessor constructor can optionally not take memobj

* Handler can specify the buffer later on
---
 placeholder_accessors/index.md | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/placeholder_accessors/index.md b/placeholder_accessors/index.md
index 8308e4b..ba935a1 100644
--- a/placeholder_accessors/index.md
+++ b/placeholder_accessors/index.md
@@ -9,7 +9,7 @@
 | Reply-to | Ruyman Reyes <ruyman@codeplay.com> |
 | Original author | Ruyman Reyes <ruyman@codeplay.com> |
 | Requirements | CP001 |
-| Contributors | Gordon Brown <gordon@codeplay.com>, Victor Lomuller <victor@codeplay.com>, Mehdi Goli <mehdi.goli@codeplay.com>, Peter Zuzek <peter@codeplay.com>, Luke Iwanski <luke@codeplay.com> |
+| Contributors | Gordon Brown <gordon@codeplay.com>, Victor Lomuller <victor@codeplay.com>, Mehdi Goli <mehdi.goli@codeplay.com>, Peter Zuzek <peter@codeplay.com>, Luke Iwanski <luke@codeplay.com>, Michael Haidl <michael.haidl@uni-muenster.de> |
 
 ## Overview
 
@@ -172,7 +172,10 @@ except for the aforementioned modifications.
 
 ### When `is_placeholder` returns true
 
-The accessor API features constructors that don't take the handler parameter.
+The accessor API features constructors that don't take the handler parameter
+and/or memory object as a constructor. Accessors can then be default
+constructed, and the memory object can be assigned later when registering
+the accessor in the command group. 
 
 In addition, a new method to obtain a normal accessor from the placeholder
 accessor is provided.
@@ -192,6 +195,12 @@ The handler gains a new method,
 that registers the requirements of the placeholder accessor on the given
 command group.
 
+Another method, that allows specifying the memory object the placeholder
+accessor will be associated is also provided:
+
+`handler::require(buffer<T, dim> b,
+    accessor<T, dim, mode, target, acess::placeholder::true_t>)`
+
 
 [1]: https://github.com/codeplaysoftware/sycl-blas "SYCL-BLAS"
 [2]: https://github.com/lukeiwanski/tensorflow "TensorFlow/Eigen"

From 117519e1cf0df09ded96484e5de7a1f549d22957 Mon Sep 17 00:00:00 2001
From: Christopher Di Bella <cjdb.ns@gmail.com>
Date: Thu, 3 Aug 2017 16:12:44 +0100
Subject: [PATCH 2/2] =?UTF-8?q?Providing=20explicit=20documentation=20for?=
 =?UTF-8?q?=20throwing=20an=20exception=20when=20no=20bu=E2=80=A6=20(#21)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

* Providing explicit documentation for throwing an exception when no buffer exists.

* Removed implementation details and provided interface specification only.

* Applied fixes to Gordon's review

* Changed has_buffer to be a const function

* Changed wording for the placeholder accessor buffer
---
 placeholder_accessors/index.md | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/placeholder_accessors/index.md b/placeholder_accessors/index.md
index ba935a1..6dd2e2c 100644
--- a/placeholder_accessors/index.md
+++ b/placeholder_accessors/index.md
@@ -175,7 +175,7 @@ except for the aforementioned modifications.
 The accessor API features constructors that don't take the handler parameter
 and/or memory object as a constructor. Accessors can then be default
 constructed, and the memory object can be assigned later when registering
-the accessor in the command group. 
+the accessor in the command group.
 
 In addition, a new method to obtain a normal accessor from the placeholder
 accessor is provided.
@@ -199,8 +199,18 @@ Another method, that allows specifying the memory object the placeholder
 accessor will be associated is also provided:
 
 `handler::require(buffer<T, dim> b,
-    accessor<T, dim, mode, target, acess::placeholder::true_t>)`
+    accessor<T, dim, mode, target, access::placeholder::true_t>)`
 
+### Placeholder `accessor` without a buffer
+
+If a placeholder accessor which was not constructed with a buffer is not tied
+to a buffer within a command group, then an exception is thrown. An accessor
+can be checked for the existence of an associated a buffer using `has_buffer()`.
+
+|Member function        |Description                                              |
+|-----------------------|---------------------------------------------------------|
+|bool has_buffer() const|Returns true if the accessor is associated with a buffer,|
+|                       |and false otherwise.                                     |
 
 [1]: https://github.com/codeplaysoftware/sycl-blas "SYCL-BLAS"
 [2]: https://github.com/lukeiwanski/tensorflow "TensorFlow/Eigen"