Clarify that read stops when buffer is full.

asio/include/asio/read.hpp

diff --git a/asio/include/asio/read.hpp b/asio/include/asio/read.hpp
index 7b93caf..acac7b8 100644
--- a/asio/include/asio/read.hpp
+++ b/asio/include/asio/read.hpp
@@ -213,6 +213,8 @@
  * This function is used to read a certain number of bytes of data from a
  * stream. The call will block until one of the following conditions is true:
  *
+ * @li The supplied buffer is full (that is, it has reached maximum size).
+ *
  * @li An error occurred.
  *
  * This operation is implemented in terms of zero or more calls to the stream's
@@ -240,6 +242,8 @@
  * This function is used to read a certain number of bytes of data from a
  * stream. The call will block until one of the following conditions is true:
  *
+ * @li The supplied buffer is full (that is, it has reached maximum size).
+ *
  * @li An error occurred.
  *
  * This operation is implemented in terms of zero or more calls to the stream's
@@ -268,6 +272,8 @@
  * This function is used to read a certain number of bytes of data from a
  * stream. The call will block until one of the following conditions is true:
  *
+ * @li The supplied buffer is full (that is, it has reached maximum size).
+ *
  * @li The completion_condition function object returns 0.
  *
  * This operation is implemented in terms of zero or more calls to the stream's
@@ -306,6 +312,8 @@
  * This function is used to read a certain number of bytes of data from a
  * stream. The call will block until one of the following conditions is true:
  *
+ * @li The supplied buffer is full (that is, it has reached maximum size).
+ *
  * @li The completion_condition function object returns 0.
  *
  * This operation is implemented in terms of zero or more calls to the stream's
@@ -495,6 +503,8 @@
  * asynchronous operation will continue until one of the following conditions is
  * true:
  *
+ * @li The supplied buffer is full (that is, it has reached maximum size).
+ *
  * @li An error occurred.
  *
  * This operation is implemented in terms of zero or more calls to the stream's
@@ -545,6 +555,8 @@
  * asynchronous operation will continue until one of the following conditions is
  * true:
  *
+ * @li The supplied buffer is full (that is, it has reached maximum size).
+ *
  * @li The completion_condition function object returns 0.
  *
  * This operation is implemented in terms of zero or more calls to the stream's