Add constants for tuple fields

Add constants for use with std::get.

Tested:  Run unit tests

Change-Id: Ic09c13feeda69d61c98f63d227cae8f08d1bf50e
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/src/count.hpp b/src/count.hpp
index 0da0324..9f0ce3e 100644
--- a/src/count.hpp
+++ b/src/count.hpp
@@ -64,18 +64,19 @@
                              {
                                  //Get the property value from storage[0],
                                  //and save the op result in storage[1].
-                                 const auto& storage = std::get<2>(
+                                 const auto& storage = std::get<storageIndex>(
                                      item.second);
                                  // Don't count properties that don't exist.
-                                 if (std::get<0>(storage.get()).empty())
+                                 if (std::get<valueIndex>(
+                                             storage.get()).empty())
                                  {
                                      return false;
                                  }
                                  const auto& value = any_ns::any_cast<T>(
-                                     std::get<0>(storage.get()));
+                                     std::get<valueIndex>(storage.get()));
                                  auto r = propertyOp(value);
 
-                                 std::get<1>(storage.get()) = r;
+                                 std::get<resultIndex>(storage.get()) = r;
 
                                  return r;
                              });
diff --git a/src/data_types.hpp b/src/data_types.hpp
index f1512db..607289a 100644
--- a/src/data_types.hpp
+++ b/src/data_types.hpp
@@ -16,11 +16,20 @@
 constexpr auto MAPPER_BUSNAME = "xyz.openbmc_project.ObjectMapper";
 constexpr auto MAPPER_PATH = "/xyz/openbmc_project/object_mapper";
 constexpr auto MAPPER_INTERFACE = "xyz.openbmc_project.ObjectMapper";
+
+//PropertyIndex::key_type fields
 constexpr auto pathIndex = 0;
+constexpr auto interfaceIndex = 1;
 constexpr auto propertyIndex = 2;
+
+//PropertyIndex::mapped_type fields
+constexpr auto pathMetaIndex = 0;
+constexpr auto propertyMetaIndex = 1;
 constexpr auto storageIndex = 2;
+
+//ConfigPropertyStorage fields
 constexpr auto valueIndex = 0;
-constexpr auto metaIndex = 1;
+constexpr auto resultIndex = 1;
 
 enum class Context
 {
diff --git a/src/elog.hpp b/src/elog.hpp
index 3f8ae3b..234ef6f 100644
--- a/src/elog.hpp
+++ b/src/elog.hpp
@@ -171,7 +171,7 @@
          * @brief Builds a metadata string with property information
          *
          * Finds all of the properties in the index that have
-         * their condition pass/fail fields (get<1>(storage))
+         * their condition pass/fail fields (get<resultIndex>(storage))
          * set to true, and then packs those paths, names, and values
          * into a metadata string that looks like:
          *
@@ -185,16 +185,17 @@
 
             for (const auto& n : index)
             {
-                const auto& storage = std::get<2>(n.second).get();
-                const auto& result = std::get<1>(storage);
+                const auto& storage = std::get<storageIndex>(n.second).get();
+                const auto& result = std::get<resultIndex>(storage);
 
                 if (!result.empty() && any_ns::any_cast<bool>(result))
                 {
-                    const auto& path = std::get<0>(n.first).get();
-                    const auto& propertyName = std::get<2>(n.first).get();
+                    const auto& path = std::get<pathIndex>(n.first).get();
+                    const auto& propertyName = std::get<propertyIndex>(
+                            n.first).get();
                     auto value = ToString<propertyType>::op(
                             any_ns::any_cast<propertyType>(
-                                    std::get<0>(storage)));
+                                    std::get<valueIndex>(storage)));
 
                     metadata += path + ":" + propertyName +
                             '=' + value + '|';
diff --git a/src/event.hpp b/src/event.hpp
index b5f1e90..b9f5167 100644
--- a/src/event.hpp
+++ b/src/event.hpp
@@ -46,7 +46,7 @@
             for (const auto& n : index)
             {
                 const auto& path = std::get<pathIndex>(n.first);
-                const auto& propertyMeta = std::get<metaIndex>(n.first);
+                const auto& propertyMeta = std::get<propertyIndex>(n.first);
                 const auto& storage = std::get<storageIndex>(n.second);
                 const auto& value = std::get<valueIndex>(storage.get());
 
diff --git a/src/journal.cpp b/src/journal.cpp
index 7069c74..f54c5b3 100644
--- a/src/journal.cpp
+++ b/src/journal.cpp
@@ -26,11 +26,11 @@
 {
     for (const auto& n : index)
     {
-        const auto& path = std::get<0>(n.first);
-        const auto& pathMeta = std::get<0>(n.second);
-        const auto& propertyMeta = std::get<1>(n.second);
-        const auto& storage = std::get<2>(n.second);
-        const auto& value = std::get<0>(storage.get());
+        const auto& path = std::get<pathIndex>(n.first);
+        const auto& pathMeta = std::get<pathMetaIndex>(n.second);
+        const auto& propertyMeta = std::get<propertyMetaIndex>(n.second);
+        const auto& storage = std::get<storageIndex>(n.second);
+        const auto& value = std::get<valueIndex>(storage.get());
 
         if (!value.empty())
         {
diff --git a/src/propertywatch.cpp b/src/propertywatch.cpp
index defde78..63a2c31 100644
--- a/src/propertywatch.cpp
+++ b/src/propertywatch.cpp
@@ -36,9 +36,9 @@
 
     for (const auto& i : index)
     {
-        const auto& path = std::get<0>(i.first);
-        const auto& interface = std::get<1>(i.first);
-        const auto& property = std::get<2>(i.first);
+        const auto& path = std::get<pathIndex>(i.first);
+        const auto& interface = std::get<interfaceIndex>(i.first);
+        const auto& property = std::get<propertyIndex>(i.first);
         m[path][interface].push_back(property);
     }
 
diff --git a/src/propertywatchimpl.hpp b/src/propertywatchimpl.hpp
index 9fe57d5..1f0e4d1 100644
--- a/src/propertywatchimpl.hpp
+++ b/src/propertywatchimpl.hpp
@@ -146,7 +146,7 @@
             continue;
         }
 
-        std::get<0>(std::get<2>(item->second).get()) =
+        std::get<valueIndex>(std::get<storageIndex>(item->second).get()) =
                 p.second.template get<T>();
 
         // Invoke callback if present.