diff --git a/arcanist/linter/CppVoidParameterLinter.php b/arcanist/linter/CppVoidParameterLinter.php
index cded20c80..07e0c60ae 100644
--- a/arcanist/linter/CppVoidParameterLinter.php
+++ b/arcanist/linter/CppVoidParameterLinter.php
@@ -1,57 +1,75 @@
 <?php
 
 /**
  * Enforce using the C++ style `()` for void parameters instead of the C style
  * `(void)`.
  */
 final class CppVoidParameterLinter extends ArcanistLinter {
 
+  const FALSE_POSITIVES = array(
+    "typeid(void)",
+  );
+
   const VOID_PARAMETER_FOUND = 1;
 
   public function getInfoName() {
     return 'lint-cpp-void-parameters';
   }
 
   public function getInfoDescription() {
     return pht('Enforce using C++ style void parameters. ');
   }
 
   public function getLinterName() {
     return 'CPP_VOID_PARAM';
   }
 
   public function getLinterConfigurationName() {
     return 'lint-cpp-void-parameters';
   }
 
   public function getLintSeverityMap() {
     return array(
         self::VOID_PARAMETER_FOUND => ArcanistLintSeverity::SEVERITY_AUTOFIX,
     );
   }
 
   public function getLintNameMap() {
     return array(
         self::VOID_PARAMETER_FOUND => pht('Use C++ style void parameters.'),
     );
   }
 
+  private function isFalsePositive($line) {
+    foreach(self::FALSE_POSITIVES as $falsePositive) {
+      if (strpos($line, $falsePositive) !== false) {
+        return true;
+      }
+    }
+    return false;
+  }
+
   public function lintPath($path) {
     $absPath = Filesystem::resolvePath($path, $this->getProjectRoot());
     $fileContent = Filesystem::readFile($absPath);
 
     if (preg_match_all('/\S+\s?\(void\)/', $fileContent, $voidParameters,
       PREG_OFFSET_CAPTURE)) {
       foreach ($voidParameters[0] as $voidParameter) {
         list($function, $offset) = $voidParameter;
+
+        if ($this->isFalsePositive($function)) {
+          continue;
+        }
+
         $this->raiseLintAtOffset(
           $offset,
           self::VOID_PARAMETER_FOUND,
           pht('C++ style parameters should be used: () instead of (void).'),
           $function,
           str_replace('(void)', '()', $function)
         )->setBypassChangedLineFiltering(true);
       }
     }
   }
 }
diff --git a/src/test/CMakeLists.txt b/src/test/CMakeLists.txt
index 42c3f85ec..b5ae9ba22 100644
--- a/src/test/CMakeLists.txt
+++ b/src/test/CMakeLists.txt
@@ -1,248 +1,249 @@
 # Copyright (c) 2018 The Bitcoin developers
 
 project(bitcoin-test)
 
 # Process json files.
 file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/data")
 
 function(gen_json_header NAME)
 	set(HEADERS "")
 	foreach(f ${ARGN})
 		set(h "${CMAKE_CURRENT_BINARY_DIR}/${f}.h")
 
 		# Get the proper name for the test variable.
 		get_filename_component(TEST_NAME ${f} NAME_WE)
 		add_custom_command(OUTPUT ${h}
 			COMMAND
 				"${Python_EXECUTABLE}"
 				"${CMAKE_CURRENT_SOURCE_DIR}/data/generate_header.py"
 				"${TEST_NAME}"
 				"${CMAKE_CURRENT_SOURCE_DIR}/${f}" > ${h}
 			MAIN_DEPENDENCY ${f}
 			DEPENDS
 				"data/generate_header.py"
 			VERBATIM
 		)
 		list(APPEND HEADERS ${h})
 	endforeach(f)
 	set(${NAME} "${HEADERS}" PARENT_SCOPE)
 endfunction()
 
 gen_json_header(JSON_HEADERS
 	data/base58_encode_decode.json
 	data/blockfilters.json
 	data/key_io_valid.json
 	data/key_io_invalid.json
 	data/script_tests.json
 	data/sighash.json
 	data/tx_invalid.json
 	data/tx_valid.json
 )
 
 include(TestSuite)
 create_test_suite(bitcoin)
 add_dependencies(check check-bitcoin)
 
 # An utility library for bitcoin related test suites.
 add_library(testutil OBJECT
 	util/blockfilter.cpp
 	util/logging.cpp
 	util/mining.cpp
 	util/setup_common.cpp
 	util/str.cpp
 	util/transaction_utils.cpp
 	util/wallet.cpp
 )
 
 target_link_libraries(testutil server)
 
 if(BUILD_BITCOIN_WALLET)
 	set(BITCOIN_WALLET_TEST_FIXTURE
 		../wallet/test/init_test_fixture.cpp
 		../wallet/test/wallet_test_fixture.cpp
 	)
 	set(BITCOIN_WALLET_TESTS
 		../wallet/test/db_tests.cpp
 		../wallet/test/coinselector_tests.cpp
 		../wallet/test/init_tests.cpp
 		../wallet/test/ismine_tests.cpp
 		../wallet/test/psbt_wallet_tests.cpp
 		../wallet/test/wallet_tests.cpp
 		../wallet/test/walletdb_tests.cpp
 		../wallet/test/wallet_crypto_tests.cpp
 	)
 endif()
 
 add_boost_unit_tests_to_suite(bitcoin test_bitcoin
 	fixture.cpp
 	jsonutil.cpp
 	scriptflags.cpp
 	sigutil.cpp
 
 	# Tests generated from JSON
 	${JSON_HEADERS}
 
 	# Wallet test fixture
 	${BITCOIN_WALLET_TEST_FIXTURE}
 
 	TESTS
 		activation_tests.cpp
 		addrman_tests.cpp
 		allocator_tests.cpp
 		amount_tests.cpp
 		arith_uint256_tests.cpp
 		base32_tests.cpp
 		base58_tests.cpp
 		base64_tests.cpp
 		bip32_tests.cpp
 		bitmanip_tests.cpp
 		blockchain_tests.cpp
 		blockcheck_tests.cpp
 		blockencodings_tests.cpp
 		blockfilter_tests.cpp
 		blockfilter_index_tests.cpp
 		blockindex_tests.cpp
 		blockstatus_tests.cpp
 		bloom_tests.cpp
 		bswap_tests.cpp
 		cashaddr_tests.cpp
 		cashaddrenc_tests.cpp
 		checkdatasig_tests.cpp
 		checkpoints_tests.cpp
 		checkqueue_tests.cpp
 		coins_tests.cpp
 		compilerbug_tests.cpp
 		compress_tests.cpp
 		config_tests.cpp
 		core_io_tests.cpp
 		crypto_tests.cpp
 		cuckoocache_tests.cpp
 		dbwrapper_tests.cpp
 		denialofservice_tests.cpp
 		descriptor_tests.cpp
 		dstencode_tests.cpp
 		excessiveblock_tests.cpp
 		feerate_tests.cpp
 		finalization_tests.cpp
 		flatfile_tests.cpp
 		fs_tests.cpp
 		getarg_tests.cpp
 		hash_tests.cpp
 		interfaces_tests.cpp
 		inv_tests.cpp
 		key_io_tests.cpp
 		key_tests.cpp
 		lcg_tests.cpp
 		limitedmap_tests.cpp
 		mempool_tests.cpp
 		merkle_tests.cpp
 		merkleblock_tests.cpp
 		miner_tests.cpp
 		monolith_opcodes_tests.cpp
 		multisig_tests.cpp
 		net_tests.cpp
 		netbase_tests.cpp
 		op_reversebytes_tests.cpp
 		pmt_tests.cpp
 		policyestimator_tests.cpp
 		prevector_tests.cpp
 		radix_tests.cpp
 		raii_event_tests.cpp
 		random_tests.cpp
 		rcu_tests.cpp
+		ref_tests.cpp
 		reverselock_tests.cpp
 		rpc_tests.cpp
 		rpc_server_tests.cpp
 		rwcollection_tests.cpp
 		sanity_tests.cpp
 		scheduler_tests.cpp
 		schnorr_tests.cpp
 		script_bitfield_tests.cpp
 		script_commitment_tests.cpp
 		script_p2sh_tests.cpp
 		script_standard_tests.cpp
 		script_tests.cpp
 		scriptnum_tests.cpp
 		serialize_tests.cpp
 		settings_tests.cpp
 		sigcache_tests.cpp
 		sigencoding_tests.cpp
 		sighash_tests.cpp
 		sighashtype_tests.cpp
 		sigcheckcount_tests.cpp
 		skiplist_tests.cpp
 		streams_tests.cpp
 		sync_tests.cpp
 		timedata_tests.cpp
 		torcontrol_tests.cpp
 		transaction_tests.cpp
 		txindex_tests.cpp
 		txvalidation_tests.cpp
 		txvalidationcache_tests.cpp
 		uint256_tests.cpp
 		undo_tests.cpp
 		util_tests.cpp
 		util_threadnames_tests.cpp
 		validation_block_tests.cpp
 		validation_tests.cpp
 		validationinterface_tests.cpp
 		versionbits_tests.cpp
 		work_comparator_tests.cpp
 
 		# RPC Tests
 		../rpc/test/server_tests.cpp
 
 		# Wallet tests
 		${BITCOIN_WALLET_TESTS}
 )
 
 function(add_boost_test_runners_with_upgrade_activated SUITE EXECUTABLE)
 	set(SUITE_UPGRADE_ACTIVATED "${SUITE}-upgrade-activated")
 	get_target_from_suite(${SUITE_UPGRADE_ACTIVATED} TARGET_UPGRADE_ACTIVATED)
 
 	if(NOT TARGET ${TARGET_UPGRADE_ACTIVATED})
 		create_test_suite_with_parent_targets(
 			${SUITE_UPGRADE_ACTIVATED}
 			check-upgrade-activated
 			check-upgrade-activated-extended
 		)
 		add_dependencies(${TARGET_UPGRADE_ACTIVATED} ${EXECUTABLE})
 	endif()
 
 	get_target_from_suite(${SUITE} SUITE_TARGET)
 	get_target_property(BOOST_TESTS ${SUITE_TARGET} UNIT_TESTS)
 
 	get_target_from_suite(${SUITE_UPGRADE_ACTIVATED} SUITE_UPGRADE_ACTIVATED_TARGET)
 
 	set(HRF_LOGGER "HRF,test_suite")
 
 	foreach(_test_name ${BOOST_TESTS})
 		if(ENABLE_JUNIT_REPORT)
 			set(JUNIT_LOGGER ":JUNIT,message,${SUITE_UPGRADE_ACTIVATED}-${_test_name}.xml")
 		endif()
 
 		add_test_runner(
 			${SUITE_UPGRADE_ACTIVATED}
 			"${_test_name}"
 			${EXECUTABLE}
 			JUNIT
 			"--run_test=${_test_name}"
 			"--logger=${HRF_LOGGER}${JUNIT_LOGGER}"
 			# Dec. 1st, 2019 at 00:00:00
 			--
 			"-testsuitename=Bitcoin ABC unit tests with next upgrade activated"
 			-axionactivationtime=1575158400
 		)
 	endforeach()
 endfunction()
 
 add_boost_test_runners_with_upgrade_activated(bitcoin test_bitcoin)
 
 target_link_libraries(test_bitcoin rpcclient testutil)
 if(TARGET bitcoinconsensus-shared)
 	target_link_libraries(test_bitcoin bitcoinconsensus-shared)
 else()
 	target_link_libraries(test_bitcoin bitcoinconsensus)
 endif()
 
 add_subdirectory(fuzz)
diff --git a/src/test/ref_tests.cpp b/src/test/ref_tests.cpp
new file mode 100644
index 000000000..beb190633
--- /dev/null
+++ b/src/test/ref_tests.cpp
@@ -0,0 +1,32 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <util/ref.h>
+
+#include <boost/test/unit_test.hpp>
+
+BOOST_AUTO_TEST_SUITE(ref_tests)
+
+BOOST_AUTO_TEST_CASE(ref_test) {
+    util::Ref ref;
+    BOOST_CHECK(!ref.Has<int>());
+    BOOST_CHECK_THROW(ref.Get<int>(), NonFatalCheckError);
+    int value = 5;
+    ref.Set(value);
+    BOOST_CHECK(ref.Has<int>());
+    BOOST_CHECK_EQUAL(ref.Get<int>(), 5);
+    ++ref.Get<int>();
+    BOOST_CHECK_EQUAL(ref.Get<int>(), 6);
+    BOOST_CHECK_EQUAL(value, 6);
+    ++value;
+    BOOST_CHECK_EQUAL(value, 7);
+    BOOST_CHECK_EQUAL(ref.Get<int>(), 7);
+    BOOST_CHECK(!ref.Has<bool>());
+    BOOST_CHECK_THROW(ref.Get<bool>(), NonFatalCheckError);
+    ref.Clear();
+    BOOST_CHECK(!ref.Has<int>());
+    BOOST_CHECK_THROW(ref.Get<int>(), NonFatalCheckError);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/util/check.h b/src/util/check.h
index 8897a391d..856632ec9 100644
--- a/src/util/check.h
+++ b/src/util/check.h
@@ -1,42 +1,46 @@
 // Copyright (c) 2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_UTIL_CHECK_H
 #define BITCOIN_UTIL_CHECK_H
 
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
 #include <tinyformat.h>
 
 #include <stdexcept>
 
 class NonFatalCheckError : public std::runtime_error {
     using std::runtime_error::runtime_error;
 };
 
 /**
  * Throw a NonFatalCheckError when the condition evaluates to false
  *
  * This should only be used
  * - where the condition is assumed to be true, not for error handling or
  * validating user input
  * - where a failure to fulfill the condition is recoverable and does not abort
  * the program
  *
  * For example in RPC code, where it is undersirable to crash the whole program,
  * this can be generally used to replace asserts or recoverable logic errors. A
  * NonFatalCheckError in RPC code is caught and passed as a string to the RPC
  * caller, which can then report the issue to the developers.
  */
 #define CHECK_NONFATAL(condition)                                              \
     do {                                                                       \
         if (!(condition)) {                                                    \
             throw NonFatalCheckError(                                          \
                 strprintf("%s:%d (%s)\n"                                       \
                           "Internal bug detected: '%s'\n"                      \
                           "You may report this issue here: %s\n",              \
                           __FILE__, __LINE__, __func__, (#condition),          \
                           PACKAGE_BUGREPORT));                                 \
         }                                                                      \
     } while (false)
 
 #endif // BITCOIN_UTIL_CHECK_H
diff --git a/src/util/ref.h b/src/util/ref.h
new file mode 100644
index 000000000..d0adea2da
--- /dev/null
+++ b/src/util/ref.h
@@ -0,0 +1,48 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_REF_H
+#define BITCOIN_UTIL_REF_H
+
+#include <util/check.h>
+
+#include <typeindex>
+
+namespace util {
+
+/**
+ * Type-safe dynamic reference.
+ *
+ * This implements a small subset of the functionality in C++17's std::any
+ * class, and can be dropped when the project updates to C++17
+ * (https://github.com/bitcoin/bitcoin/issues/16684)
+ */
+class Ref {
+public:
+    Ref() = default;
+    template <typename T> Ref(T &value) { Set(value); }
+    template <typename T> T &Get() const {
+        CHECK_NONFATAL(Has<T>());
+        return *static_cast<T *>(m_value);
+    }
+    template <typename T> void Set(T &value) {
+        m_value = &value;
+        m_type = std::type_index(typeid(T));
+    }
+    template <typename T> bool Has() const {
+        return m_value && m_type == std::type_index(typeid(T));
+    }
+    void Clear() {
+        m_value = nullptr;
+        m_type = std::type_index(typeid(void));
+    }
+
+private:
+    void *m_value = nullptr;
+    std::type_index m_type = std::type_index(typeid(void));
+};
+
+} // namespace util
+
+#endif // BITCOIN_UTIL_REF_H