commit 94c4374133cb14c59c7afc62c9c8f052b5cc388a
author Steven Moreland <smoreland@google.com> Tue May 21 17:47:12 2019 -0700
committer Steven Moreland <smoreland@google.com> Wed May 22 11:15:38 2019 -0700
tree 2f3e0c0c63cf48cd696f4393b621035b0eb85253
parent 7860da3648e5005df574e667fb433c4302d7697f

Expound on HIDL Return errors.

Add 'onValueRetrieval' error which explicitly talks about the error
being while retrieving a value (since 'assertOk' was publically
exposed, it no longer makes sense to have a specific error).

assertOk is now also used in ~return_status and contains even more
information about how to interpret the error.

Bug: many
Test: TH

Change-Id: I80a7ec2ae42b7980a0a84fc760d5b27b17f293db

base/include/hidl/Status.h

diff --git a/base/include/hidl/Status.h b/base/include/hidl/Status.h
index 817277f..07d352f 100644
--- a/base/include/hidl/Status.h
+++ b/base/include/hidl/Status.h
@@ -143,6 +143,8 @@
 
         template <typename T, typename U>
         friend Return<U> StatusOf(const Return<T> &other);
+    protected:
+        void onValueRetrieval() const;
     public:
         void assertOk() const;
         return_status() {}
@@ -224,7 +226,7 @@
     ~Return() = default;
 
     operator T() const {
-        assertOk();
+        onValueRetrieval();  // assert okay
         return mVal;
     }
 
@@ -253,7 +255,7 @@
     ~Return() = default;
 
     operator sp<T>() const {
-        assertOk();
+        onValueRetrieval();  // assert okay
         return mVal;
     }