GOEDO-8534: fix xcode 12 build (#657)

* GEODE-8534: Fix build errors after upgrade to XCode 12

Co-authored-by: Blake Bender <bblake@vmware.com>
diff --git a/cppcache/integration-test/ThinClientPutGetAll.hpp b/cppcache/integration-test/ThinClientPutGetAll.hpp
index f1def7d..e69839d 100644
--- a/cppcache/integration-test/ThinClientPutGetAll.hpp
+++ b/cppcache/integration-test/ThinClientPutGetAll.hpp
@@ -89,20 +89,14 @@
 
   auto valuesMap = region->getAll(keys1, callBack);
   if (valuesMap.size() == keys1.size()) {
-    char buf[2048];
     for (const auto& iter : valuesMap) {
       const auto key = std::dynamic_pointer_cast<CacheableKey>(iter.first);
-      const auto actualKey = key->toString().c_str();
       const auto& mVal = iter.second;
       if (mVal != nullptr) {
-        const auto expectedVal = expected[actualKey].c_str();
-        const auto actualVal = mVal->toString().c_str();
-        sprintf(buf, "value from map %s , expected value %s ", actualVal,
-                expectedVal);
-        LOG(buf);
-        ASSERT(strcmp(actualVal, expectedVal) == 0, "value not matched");
+        LOG(std::string("Value from map ") + mVal->toString() + ", expected value " + expected[key->toString()]);
+        ASSERT(mVal->toString() == expected[key->toString()], "value not matched");
       } else {
-        ASSERT(strcmp(actualKey, "keyNotThere") == 0,
+        ASSERT(key->toString() == "keyNotThere",
                "keyNotThere value is not null");
       }
     }
diff --git a/cppcache/src/ClientProxyMembershipIDFactory.cpp b/cppcache/src/ClientProxyMembershipIDFactory.cpp
index b4d653f..43f41cb 100644
--- a/cppcache/src/ClientProxyMembershipIDFactory.cpp
+++ b/cppcache/src/ClientProxyMembershipIDFactory.cpp
@@ -33,9 +33,9 @@
 ClientProxyMembershipIDFactory::ClientProxyMembershipIDFactory(
     std::string dsName)
     : dsName_(std::move(dsName)) {
-  static const auto alphabet =
-      "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_";
-  static const auto numChars = (sizeof(alphabet) / sizeof(char)) - 2;
+  static const auto alphabet = std::string(
+      "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_");
+  static const auto numChars = static_cast<int>(alphabet.size()) - 2;
 
   std::random_device rd;
   std::default_random_engine rng(rd());