diff --git a/src/test/radix_tests.cpp b/src/test/radix_tests.cpp
index b6c293151..ead1d0498 100644
--- a/src/test/radix_tests.cpp
+++ b/src/test/radix_tests.cpp
@@ -1,380 +1,371 @@
 // Copyright (c) 2019 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <radix.h>
 
 #include "test/lcg.h"
 #include <test/test_bitcoin.h>
 
 #include <boost/test/unit_test.hpp>
 
 #include <limits>
 #include <type_traits>
 
 BOOST_FIXTURE_TEST_SUITE(radix_tests, BasicTestingSetup)
 
-/**
- * Version of Boost::test prior to 1.64 have issues when dealing with nullptr_t.
- * In order to work around this, we ensure that the null pointers are typed in a
- * way that Boost will like better.
- *
- * TODO: Use nullptr directly once the minimum version of boost is 1.64 or more.
- */
-#define NULLPTR(T) static_cast<T *>(nullptr)
-
 template <typename K> struct TestElement {
     K key;
 
     TestElement(K keyIn) : key(keyIn) {}
     const K &getId() const { return key; }
 
     IMPLEMENT_RCU_REFCOUNT(uint32_t);
 };
 
 template <typename K> void testInsert() {
     typedef TestElement<K> E;
     RadixTree<E> mytree;
 
     auto zero = RCUPtr<E>::make(0);
     auto one = RCUPtr<E>::make(1);
     auto two = RCUPtr<E>::make(2);
     auto three = RCUPtr<E>::make(3);
 
     // Inserting a new element into the tree returns true.
     BOOST_CHECK(mytree.insert(one));
 
     // Inserting an element already in the tree returns false.
     BOOST_CHECK(!mytree.insert(one));
 
     // Let's insert more elements and check behavior stays consistent.
     BOOST_CHECK(mytree.insert(zero));
     BOOST_CHECK(!mytree.insert(one));
     BOOST_CHECK(mytree.insert(two));
     BOOST_CHECK(mytree.insert(three));
     BOOST_CHECK(!mytree.insert(zero));
     BOOST_CHECK(!mytree.insert(one));
     BOOST_CHECK(!mytree.insert(two));
     BOOST_CHECK(!mytree.insert(three));
 
     // Check extreme values.
     typedef typename std::make_signed<K>::type SK;
     auto maxsigned = RCUPtr<E>::make(std::numeric_limits<SK>::max());
     auto minsigned = RCUPtr<E>::make(std::numeric_limits<SK>::min());
     typedef typename std::make_unsigned<K>::type UK;
     auto minusone = RCUPtr<E>::make(std::numeric_limits<UK>::max());
     auto minustwo = RCUPtr<E>::make(std::numeric_limits<UK>::max() - 1);
 
     // Insert them into the tree.
     BOOST_CHECK(mytree.insert(maxsigned));
     BOOST_CHECK(mytree.insert(minsigned));
     BOOST_CHECK(mytree.insert(minusone));
     BOOST_CHECK(mytree.insert(minustwo));
 
     // All elements are now in the tree.
     BOOST_CHECK(!mytree.insert(zero));
     BOOST_CHECK(!mytree.insert(one));
     BOOST_CHECK(!mytree.insert(two));
     BOOST_CHECK(!mytree.insert(three));
     BOOST_CHECK(!mytree.insert(maxsigned));
     BOOST_CHECK(!mytree.insert(minsigned));
     BOOST_CHECK(!mytree.insert(minusone));
     BOOST_CHECK(!mytree.insert(minustwo));
 }
 
 BOOST_AUTO_TEST_CASE(insert_test) {
     testInsert<int32_t>();
     testInsert<uint32_t>();
     testInsert<int64_t>();
     testInsert<uint64_t>();
 }
 
 template <typename K> void testGet() {
     typedef TestElement<K> E;
     RadixTree<E> mytree;
 
     auto zero = RCUPtr<E>::make(0);
     auto one = RCUPtr<E>::make(1);
     auto two = RCUPtr<E>::make(2);
     auto three = RCUPtr<E>::make(3);
 
     // There are no elements in the tree so far.
     BOOST_CHECK_EQUAL(mytree.get(1), NULLPTR(E));
 
     // Insert an element into the tree and check it is there.
     BOOST_CHECK(mytree.insert(one));
     BOOST_CHECK_EQUAL(mytree.get(1), one);
 
     // Let's insert more elements and check they are recovered properly.
     BOOST_CHECK_EQUAL(mytree.get(0), NULLPTR(E));
     BOOST_CHECK(mytree.insert(zero));
     BOOST_CHECK_EQUAL(mytree.get(0), zero);
     BOOST_CHECK_EQUAL(mytree.get(1), one);
 
     // More elements.
     BOOST_CHECK_EQUAL(mytree.get(2), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(3), NULLPTR(E));
     BOOST_CHECK(mytree.insert(two));
     BOOST_CHECK(mytree.insert(three));
 
     BOOST_CHECK_EQUAL(mytree.get(0), zero);
     BOOST_CHECK_EQUAL(mytree.get(1), one);
     BOOST_CHECK_EQUAL(mytree.get(2), two);
     BOOST_CHECK_EQUAL(mytree.get(3), three);
 
     // Check extreme values.
     typedef typename std::make_signed<K>::type SK;
     K maxsk = std::numeric_limits<SK>::max();
     K minsk = std::numeric_limits<SK>::min();
     typedef typename std::make_unsigned<K>::type UK;
     K maxuk = std::numeric_limits<UK>::max();
 
     auto maxsigned = RCUPtr<E>::make(maxsk);
     auto minsigned = RCUPtr<E>::make(minsk);
     auto minusone = RCUPtr<E>::make(maxuk);
     auto minustwo = RCUPtr<E>::make(maxuk - 1);
 
     // Check that they are not in the tree.
     BOOST_CHECK_EQUAL(mytree.get(maxsk), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(minsk), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(maxuk), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(maxuk - 1), NULLPTR(E));
 
     // Insert into the tree.
     BOOST_CHECK(mytree.insert(maxsigned));
     BOOST_CHECK(mytree.insert(minsigned));
     BOOST_CHECK(mytree.insert(minusone));
     BOOST_CHECK(mytree.insert(minustwo));
 
     // And now they all are in the tree.
     BOOST_CHECK_EQUAL(mytree.get(0), zero);
     BOOST_CHECK_EQUAL(mytree.get(1), one);
     BOOST_CHECK_EQUAL(mytree.get(2), two);
     BOOST_CHECK_EQUAL(mytree.get(3), three);
     BOOST_CHECK_EQUAL(mytree.get(maxsk), maxsigned);
     BOOST_CHECK_EQUAL(mytree.get(minsk), minsigned);
     BOOST_CHECK_EQUAL(mytree.get(maxuk), minusone);
     BOOST_CHECK_EQUAL(mytree.get(maxuk - 1), minustwo);
 }
 
 BOOST_AUTO_TEST_CASE(get_test) {
     testGet<int32_t>();
     testGet<uint32_t>();
     testGet<int64_t>();
     testGet<uint64_t>();
 }
 
 template <typename K> void testRemove() {
     typedef TestElement<K> E;
     RadixTree<E> mytree;
 
     auto zero = RCUPtr<E>::make(0);
     auto one = RCUPtr<E>::make(1);
     auto two = RCUPtr<E>::make(2);
     auto three = RCUPtr<E>::make(3);
 
     // Removing an element that isn't in the tree returns false.
     BOOST_CHECK(!mytree.remove(1));
 
     // Insert an element into the tree and check you can remove it.
     BOOST_CHECK(mytree.insert(one));
     BOOST_CHECK(mytree.remove(1));
     BOOST_CHECK_EQUAL(mytree.get(1), NULLPTR(E));
 
     // Insert several elements and remove them.
     BOOST_CHECK(mytree.insert(zero));
     BOOST_CHECK(mytree.insert(one));
     BOOST_CHECK(mytree.insert(two));
     BOOST_CHECK(mytree.insert(three));
 
     BOOST_CHECK(mytree.remove(0));
     BOOST_CHECK(mytree.remove(1));
     BOOST_CHECK(mytree.remove(2));
     BOOST_CHECK(mytree.remove(3));
 
     BOOST_CHECK_EQUAL(mytree.get(0), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(1), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(2), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(3), NULLPTR(E));
 
     // Once the elements are removed, removing them again returns false.
     BOOST_CHECK(!mytree.remove(0));
     BOOST_CHECK(!mytree.remove(1));
     BOOST_CHECK(!mytree.remove(2));
     BOOST_CHECK(!mytree.remove(3));
 
     // Check extreme values.
     typedef typename std::make_signed<K>::type SK;
     K maxsk = std::numeric_limits<SK>::max();
     K minsk = std::numeric_limits<SK>::min();
     typedef typename std::make_unsigned<K>::type UK;
     K maxuk = std::numeric_limits<UK>::max();
 
     auto maxsigned = RCUPtr<E>::make(maxsk);
     auto minsigned = RCUPtr<E>::make(minsk);
     auto minusone = RCUPtr<E>::make(maxuk);
     auto minustwo = RCUPtr<E>::make(maxuk - 1);
 
     // Insert them all.
     BOOST_CHECK(mytree.insert(zero));
     BOOST_CHECK(mytree.insert(one));
     BOOST_CHECK(mytree.insert(two));
     BOOST_CHECK(mytree.insert(three));
     BOOST_CHECK(mytree.insert(maxsigned));
     BOOST_CHECK(mytree.insert(minsigned));
     BOOST_CHECK(mytree.insert(minusone));
     BOOST_CHECK(mytree.insert(minustwo));
 
     // Delete them all
     BOOST_CHECK(mytree.remove(0));
     BOOST_CHECK(mytree.remove(1));
     BOOST_CHECK(mytree.remove(2));
     BOOST_CHECK(mytree.remove(3));
     BOOST_CHECK(mytree.remove(maxsk));
     BOOST_CHECK(mytree.remove(minsk));
     BOOST_CHECK(mytree.remove(maxuk));
     BOOST_CHECK(mytree.remove(maxuk - 1));
 
     BOOST_CHECK_EQUAL(mytree.get(0), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(1), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(2), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(3), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(maxsk), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(minsk), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(maxuk), NULLPTR(E));
     BOOST_CHECK_EQUAL(mytree.get(maxuk - 1), NULLPTR(E));
 }
 
 BOOST_AUTO_TEST_CASE(remove_test) {
     testRemove<int32_t>();
     testRemove<uint32_t>();
     testRemove<int64_t>();
     testRemove<uint64_t>();
 }
 
 BOOST_AUTO_TEST_CASE(const_element_test) {
     typedef const TestElement<uint64_t> C;
     RadixTree<C> mytree;
 
     BOOST_CHECK(mytree.insert(RCUPtr<C>::make(0)));
     BOOST_CHECK(mytree.insert(RCUPtr<C>::make(1)));
     BOOST_CHECK(mytree.insert(RCUPtr<C>::make(2)));
     BOOST_CHECK(mytree.insert(RCUPtr<C>::make(3)));
 
     BOOST_CHECK(!mytree.insert(RCUPtr<C>::make(0)));
     BOOST_CHECK(!mytree.insert(RCUPtr<C>::make(1)));
     BOOST_CHECK(!mytree.insert(RCUPtr<C>::make(2)));
     BOOST_CHECK(!mytree.insert(RCUPtr<C>::make(3)));
 
     BOOST_CHECK(mytree.get(0));
     BOOST_CHECK(mytree.get(1));
     BOOST_CHECK(mytree.get(2));
     BOOST_CHECK(mytree.get(3));
 
     BOOST_CHECK(mytree.remove(0));
     BOOST_CHECK(mytree.remove(1));
     BOOST_CHECK(mytree.remove(2));
     BOOST_CHECK(mytree.remove(3));
 
     BOOST_CHECK(!mytree.get(0));
     BOOST_CHECK(!mytree.get(1));
     BOOST_CHECK(!mytree.get(2));
     BOOST_CHECK(!mytree.get(3));
 
     BOOST_CHECK(!mytree.remove(0));
     BOOST_CHECK(!mytree.remove(1));
     BOOST_CHECK(!mytree.remove(2));
     BOOST_CHECK(!mytree.remove(3));
 }
 
 void CheckConstTree(const RadixTree<TestElement<uint64_t>> &mytree,
                     bool expected) {
     BOOST_CHECK_EQUAL(!!mytree.get(0), expected);
     BOOST_CHECK_EQUAL(!!mytree.get(1), expected);
     BOOST_CHECK_EQUAL(!!mytree.get(2), expected);
     BOOST_CHECK_EQUAL(!!mytree.get(3), expected);
 }
 
 BOOST_AUTO_TEST_CASE(const_tree_test) {
     typedef TestElement<uint64_t> E;
     RadixTree<E> mytree;
 
     CheckConstTree(mytree, false);
 
     BOOST_CHECK(mytree.insert(RCUPtr<E>::make(0)));
     BOOST_CHECK(mytree.insert(RCUPtr<E>::make(1)));
     BOOST_CHECK(mytree.insert(RCUPtr<E>::make(2)));
     BOOST_CHECK(mytree.insert(RCUPtr<E>::make(3)));
 
     CheckConstTree(mytree, true);
 
     BOOST_CHECK(mytree.remove(0));
     BOOST_CHECK(mytree.remove(1));
     BOOST_CHECK(mytree.remove(2));
     BOOST_CHECK(mytree.remove(3));
 
     CheckConstTree(mytree, false);
 }
 
 #define THREADS 128
 #define ELEMENTS 65536
 
 BOOST_AUTO_TEST_CASE(insert_stress_test) {
     typedef TestElement<uint32_t> E;
 
     RadixTree<E> mytree;
     std::atomic<uint32_t> success{0};
     std::vector<std::thread> threads;
 
     for (int i = 0; i < THREADS; i++) {
         threads.push_back(std::thread([&] {
             MMIXLinearCongruentialGenerator lcg;
             for (int j = 0; j < ELEMENTS; j++) {
                 uint32_t v = lcg.next();
 
                 if (mytree.remove(v)) {
                     success--;
                     std::this_thread::yield();
                 }
 
                 auto ptr = RCUPtr<E>::make(v);
                 if (mytree.insert(ptr)) {
                     success++;
                     std::this_thread::yield();
                 }
 
                 if (mytree.remove(v)) {
                     success--;
                     std::this_thread::yield();
                 }
 
                 if (mytree.insert(ptr)) {
                     success++;
                     std::this_thread::yield();
                 }
             }
         }));
     }
 
     // Wait for all the threads to finish.
     for (std::thread &t : threads) {
         t.join();
     }
 
     BOOST_CHECK_EQUAL(success.load(), ELEMENTS);
 
     // All the elements have been inserted into the tree.
     MMIXLinearCongruentialGenerator lcg;
     for (int i = 0; i < ELEMENTS; i++) {
         uint32_t v = lcg.next();
         BOOST_CHECK_EQUAL(mytree.get(v)->getId(), v);
         auto ptr = RCUPtr<E>::make(v);
         BOOST_CHECK(!mytree.insert(ptr));
         BOOST_CHECK(mytree.get(v) != ptr);
     }
 
     // Cleanup after ourselves.
     RCULock::synchronize();
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/rcu_tests.cpp b/src/test/rcu_tests.cpp
index cf4296e5f..eb763c5e3 100644
--- a/src/test/rcu_tests.cpp
+++ b/src/test/rcu_tests.cpp
@@ -1,400 +1,391 @@
 // Copyright (c) 2018 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "rcu.h"
 
 #include "test/test_bitcoin.h"
 
 #include <boost/test/unit_test.hpp>
 
 #include <chrono>
 
 struct RCUTest {
     static uint64_t getRevision() { return RCUInfos::revision.load(); }
 
     static uint64_t hasSyncedTo(uint64_t syncRev) {
         return RCUInfos::infos.hasSyncedTo(syncRev);
     }
 
     static std::map<uint64_t, std::function<void()>> &getCleanups() {
         return RCUInfos::infos.cleanups;
     }
 };
 
 BOOST_FIXTURE_TEST_SUITE(rcu_tests, BasicTestingSetup)
 
 enum RCUTestStep {
     Init,
     Locked,
     LockAck,
     RCULocked,
     Synchronizing,
     Synchronized,
 };
 
 #define WAIT_FOR_STEP(step)                                                    \
     do {                                                                       \
         cond.notify_all();                                                     \
     } while (!cond.wait_for(lock, std::chrono::milliseconds(1),                \
                             [&] { return otherstep == step; }))
 
 void synchronize(std::atomic<RCUTestStep> &step,
                  const std::atomic<RCUTestStep> &otherstep,
                  CWaitableCriticalSection &cs, std::condition_variable &cond,
                  std::atomic<uint64_t> &syncRev) {
     assert(step == RCUTestStep::Init);
 
     {
         WAIT_LOCK(cs, lock);
         step = RCUTestStep::Locked;
 
         // Wait for our lock to be acknowledged.
         WAIT_FOR_STEP(RCUTestStep::LockAck);
 
         RCULock rculock;
 
         // Update step.
         step = RCUTestStep::RCULocked;
 
         // Wait for master.
         WAIT_FOR_STEP(RCUTestStep::RCULocked);
     }
 
     // Update step.
     syncRev = RCUTest::getRevision() + 1;
     step = RCUTestStep::Synchronizing;
 
     assert(!RCUTest::hasSyncedTo(syncRev));
 
     // We wait for readers.
     RCULock::synchronize();
 
     // Update step.
     step = RCUTestStep::Synchronized;
 }
 
 void lockAndWaitForSynchronize(std::atomic<RCUTestStep> &step,
                                const std::atomic<RCUTestStep> &otherstep,
                                CWaitableCriticalSection &cs,
                                std::condition_variable &cond,
                                std::atomic<uint64_t> &syncRev) {
     assert(step == RCUTestStep::Init);
     WAIT_LOCK(cs, lock);
 
     // Wait for th eother thread to be locked.
     WAIT_FOR_STEP(RCUTestStep::Locked);
     step = RCUTestStep::LockAck;
 
     // Wait for the synchronizing tread to take its RCU lock.
     WAIT_FOR_STEP(RCUTestStep::RCULocked);
     assert(!RCUTest::hasSyncedTo(syncRev));
 
     {
         RCULock rculock;
 
         // Update master step.
         step = RCUTestStep::RCULocked;
 
         while (RCUTest::getRevision() < syncRev) {
             WAIT_FOR_STEP(RCUTestStep::Synchronizing);
         }
 
         assert(RCUTest::getRevision() >= syncRev);
         assert(otherstep.load() == RCUTestStep::Synchronizing);
     }
 
     assert(RCUTest::hasSyncedTo(syncRev) >= syncRev);
     WAIT_FOR_STEP(RCUTestStep::Synchronized);
 }
 
 static const int COUNT = 128;
 
 BOOST_AUTO_TEST_CASE(synchronize_test) {
     CWaitableCriticalSection cs;
     std::condition_variable cond;
     std::atomic<RCUTestStep> parentstep;
     std::atomic<RCUTestStep> childstep;
     std::atomic<uint64_t> syncRev;
 
     for (int i = 0; i < COUNT; i++) {
         parentstep = RCUTestStep::Init;
         childstep = RCUTestStep::Init;
         syncRev = RCUTest::getRevision() + 1;
 
         std::thread tlock([&] {
             lockAndWaitForSynchronize(parentstep, childstep, cs, cond, syncRev);
         });
 
         std::thread tsync(
             [&] { synchronize(childstep, parentstep, cs, cond, syncRev); });
 
         tlock.join();
         tsync.join();
     }
 }
 
-/**
- * Version of Boost::test prior to 1.64 have issues when dealing with nullptr_t.
- * In order to work around this, we ensure that the null pointers are typed in a
- * way that Boost will like better.
- *
- * TODO: Use nullptr directly once the minimum version of boost is 1.64 or more.
- */
-#define NULLPTR(T) static_cast<T *>(nullptr)
-
 BOOST_AUTO_TEST_CASE(cleanup_test) {
     RCULock::synchronize();
     BOOST_CHECK(RCUTest::getCleanups().empty());
 
     bool isClean1 = false;
     RCULock::registerCleanup([&] { isClean1 = true; });
 
     BOOST_CHECK(!isClean1);
     BOOST_CHECK_EQUAL(RCUTest::getCleanups().size(), 1);
     BOOST_CHECK_EQUAL(RCUTest::getRevision(),
                       RCUTest::getCleanups().begin()->first);
 
     // Synchronize runs the cleanups.
     RCULock::synchronize();
     BOOST_CHECK(RCUTest::getCleanups().empty());
     BOOST_CHECK(isClean1);
 
     // Check multiple callbacks.
     isClean1 = false;
     bool isClean2 = false;
     bool isClean3 = false;
     RCULock::registerCleanup([&] { isClean1 = true; });
     RCULock::registerCleanup([&] { isClean2 = true; });
     RCULock::registerCleanup([&] { isClean3 = true; });
 
     BOOST_CHECK_EQUAL(RCUTest::getCleanups().size(), 3);
     RCULock::synchronize();
     BOOST_CHECK(RCUTest::getCleanups().empty());
     BOOST_CHECK(isClean1);
     BOOST_CHECK(isClean2);
     BOOST_CHECK(isClean3);
 
     // Check callbacks adding each others.
     isClean1 = false;
     isClean2 = false;
     isClean3 = false;
 
     RCULock::registerCleanup([&] {
         isClean1 = true;
         RCULock::registerCleanup([&] {
             isClean2 = true;
             RCULock::registerCleanup([&] { isClean3 = true; });
         });
     });
 
     BOOST_CHECK_EQUAL(RCUTest::getCleanups().size(), 1);
     RCULock::synchronize();
     BOOST_CHECK(RCUTest::getCleanups().empty());
     BOOST_CHECK(isClean1);
     BOOST_CHECK(isClean2);
     BOOST_CHECK(isClean3);
 }
 
 class RCURefTestItem {
     IMPLEMENT_RCU_REFCOUNT(uint32_t);
     const std::function<void()> cleanupfun;
 
 public:
     explicit RCURefTestItem(const std::function<void()> &fun)
         : cleanupfun(fun) {}
     ~RCURefTestItem() { cleanupfun(); }
 
     uint32_t getRefCount() const { return refcount.load(); }
 };
 
 BOOST_AUTO_TEST_CASE(rcuptr_test) {
     // Make sure it works for null.
     {
         RCURefTestItem *ptr = nullptr;
         RCUPtr<RCURefTestItem>::copy(ptr);
         RCUPtr<RCURefTestItem>::acquire(ptr);
     }
 
     // Check the destruction mechanism.
     bool isDestroyed = false;
 
     {
         auto rcuptr = RCUPtr<RCURefTestItem>::make([&] { isDestroyed = true; });
         BOOST_CHECK_EQUAL(rcuptr->getRefCount(), 0);
     }
 
     // rcuptr waits for synchronization to destroy.
     BOOST_CHECK(!isDestroyed);
     RCULock::synchronize();
     BOOST_CHECK(isDestroyed);
 
     // Check that copy behaves properly.
     isDestroyed = false;
     RCUPtr<RCURefTestItem> gptr;
 
     {
         auto rcuptr = RCUPtr<RCURefTestItem>::make([&] { isDestroyed = true; });
         BOOST_CHECK_EQUAL(rcuptr->getRefCount(), 0);
 
         gptr = rcuptr;
         BOOST_CHECK_EQUAL(rcuptr->getRefCount(), 1);
         BOOST_CHECK_EQUAL(gptr->getRefCount(), 1);
 
         auto rcuptrcopy = rcuptr;
         BOOST_CHECK_EQUAL(rcuptrcopy->getRefCount(), 2);
         BOOST_CHECK_EQUAL(rcuptr->getRefCount(), 2);
         BOOST_CHECK_EQUAL(gptr->getRefCount(), 2);
     }
 
     BOOST_CHECK_EQUAL(gptr->getRefCount(), 0);
     RCULock::synchronize();
     BOOST_CHECK(!isDestroyed);
 
     gptr = RCUPtr<RCURefTestItem>();
     BOOST_CHECK(!isDestroyed);
     RCULock::synchronize();
     BOOST_CHECK(isDestroyed);
 }
 
 BOOST_AUTO_TEST_CASE(rcuptr_operator_test) {
     auto gptr = RCUPtr<RCURefTestItem>();
     auto ptr = new RCURefTestItem([] {});
     auto oldPtr = ptr;
 
     auto altptr = RCUPtr<RCURefTestItem>::make([] {});
 
     // Check various operators.
     BOOST_CHECK_EQUAL(gptr.get(), NULLPTR(RCURefTestItem));
     BOOST_CHECK_EQUAL(&*gptr, NULLPTR(RCURefTestItem));
     BOOST_CHECK_EQUAL(gptr, NULLPTR(RCURefTestItem));
     BOOST_CHECK(!gptr);
 
     auto copyptr = gptr;
     BOOST_CHECK(gptr == nullptr);
     BOOST_CHECK(gptr != oldPtr);
     BOOST_CHECK(gptr == copyptr);
     BOOST_CHECK(gptr != altptr);
 
     gptr = RCUPtr<RCURefTestItem>::acquire(ptr);
     BOOST_CHECK_EQUAL(ptr, NULLPTR(RCURefTestItem));
 
     BOOST_CHECK_EQUAL(gptr.get(), oldPtr);
     BOOST_CHECK_EQUAL(&*gptr, oldPtr);
     BOOST_CHECK_EQUAL(gptr, oldPtr);
     BOOST_CHECK(gptr);
 
     copyptr = gptr;
     BOOST_CHECK(gptr != nullptr);
     BOOST_CHECK(gptr == oldPtr);
     BOOST_CHECK(gptr == copyptr);
     BOOST_CHECK(gptr != altptr);
 }
 
 BOOST_AUTO_TEST_CASE(const_rcuptr_test) {
     bool isDestroyed = false;
     auto ptr = RCUPtr<const RCURefTestItem>::make([&] { isDestroyed = true; });
 
     // Now let's destroy it.
     ptr = RCUPtr<const RCURefTestItem>();
     BOOST_CHECK(!isDestroyed);
     RCULock::synchronize();
     BOOST_CHECK(isDestroyed);
 }
 
 class RCURefMoveTestItem {
     const std::function<void()> cleanupfun;
 
 public:
     explicit RCURefMoveTestItem(const std::function<void()> &fun)
         : cleanupfun(fun) {}
     ~RCURefMoveTestItem() { cleanupfun(); }
 
     void acquire() {
         throw std::runtime_error("RCUPtr incremented the refcount");
     }
     void release() {
         RCULock::registerCleanup([this] { delete this; });
     }
 };
 
 BOOST_AUTO_TEST_CASE(move_rcuptr_test) {
     bool isDestroyed = false;
 
     // Check tat copy is failing.
     auto rcuptr1 =
         RCUPtr<RCURefMoveTestItem>::make([&] { isDestroyed = true; });
     BOOST_CHECK_THROW(rcuptr1->acquire(), std::runtime_error);
     BOOST_CHECK_THROW(auto rcuptrcopy = rcuptr1;, std::runtime_error);
 
     // Try to move.
     auto rcuptr2 = std::move(rcuptr1);
     RCULock::synchronize();
     BOOST_CHECK(!isDestroyed);
 
     // Move to a local and check proper destruction.
     { auto rcuptr3 = std::move(rcuptr2); }
 
     BOOST_CHECK(!isDestroyed);
     RCULock::synchronize();
     BOOST_CHECK(isDestroyed);
 
     // Let's try to swap.
     isDestroyed = false;
     rcuptr1 = RCUPtr<RCURefMoveTestItem>::make([&] { isDestroyed = true; });
     std::swap(rcuptr1, rcuptr2);
 
     RCULock::synchronize();
     BOOST_CHECK(!isDestroyed);
 
     // Chain moves to make sure there are no double free.
     {
         auto rcuptr3 = std::move(rcuptr2);
         auto rcuptr4 = std::move(rcuptr3);
         std::swap(rcuptr1, rcuptr4);
     }
 
     RCULock::synchronize();
     BOOST_CHECK(!isDestroyed);
 
     // Check we can return from a function.
     {
         auto r = ([&] {
             auto moved = std::move(rcuptr1);
             return moved;
         })();
 
         RCULock::synchronize();
         BOOST_CHECK(!isDestroyed);
     }
 
     BOOST_CHECK(!isDestroyed);
     RCULock::synchronize();
     BOOST_CHECK(isDestroyed);
 
     // Acquire/release workflow.
     isDestroyed = false;
     auto ptr = new RCURefMoveTestItem([&] { isDestroyed = true; });
     auto ptrCopy = ptr;
     BOOST_CHECK_THROW(RCUPtr<RCURefMoveTestItem>::copy(ptr),
                       std::runtime_error);
 
     rcuptr1 = RCUPtr<RCURefMoveTestItem>::acquire(ptr);
     BOOST_CHECK_EQUAL(rcuptr1, ptrCopy);
     BOOST_CHECK_EQUAL(ptr, NULLPTR(RCURefMoveTestItem));
 
     ptr = rcuptr1.release();
     BOOST_CHECK_EQUAL(rcuptr1, NULLPTR(RCURefMoveTestItem));
     BOOST_CHECK_EQUAL(ptr, ptrCopy);
 
     RCULock::synchronize();
     BOOST_CHECK(!isDestroyed);
 
     RCUPtr<RCURefMoveTestItem>::acquire(ptr);
     BOOST_CHECK_EQUAL(ptr, NULLPTR(RCURefMoveTestItem));
     BOOST_CHECK(!isDestroyed);
     RCULock::synchronize();
     BOOST_CHECK(isDestroyed);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/test_bitcoin.h b/src/test/test_bitcoin.h
index 333a6ba72..ef6ead82d 100644
--- a/src/test/test_bitcoin.h
+++ b/src/test/test_bitcoin.h
@@ -1,156 +1,165 @@
 // Copyright (c) 2015-2016 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_TEST_TEST_BITCOIN_H
 #define BITCOIN_TEST_TEST_BITCOIN_H
 
 #include "chainparamsbase.h"
 #include "fs.h"
 #include "key.h"
 #include "pubkey.h"
 #include "random.h"
 #include "scheduler.h"
 #include "txdb.h"
 #include "txmempool.h"
 
 #include <boost/thread.hpp>
 
+/**
+ * Version of Boost::test prior to 1.64 have issues when dealing with nullptr_t.
+ * In order to work around this, we ensure that the null pointers are typed in a
+ * way that Boost will like better.
+ *
+ * TODO: Use nullptr directly once the minimum version of boost is 1.64 or more.
+ */
+#define NULLPTR(T) static_cast<T *>(nullptr)
+
 extern uint256 insecure_rand_seed;
 extern FastRandomContext insecure_rand_ctx;
 
 static inline void SeedInsecureRand(bool fDeterministic = false) {
     if (fDeterministic) {
         insecure_rand_seed = uint256();
     } else {
         insecure_rand_seed = GetRandHash();
     }
     insecure_rand_ctx = FastRandomContext(insecure_rand_seed);
 }
 
 static inline uint32_t insecure_rand() {
     return insecure_rand_ctx.rand32();
 }
 static inline uint256 InsecureRand256() {
     return insecure_rand_ctx.rand256();
 }
 static inline uint64_t InsecureRandBits(int bits) {
     return insecure_rand_ctx.randbits(bits);
 }
 static inline uint64_t InsecureRandRange(uint64_t range) {
     return insecure_rand_ctx.randrange(range);
 }
 static inline bool InsecureRandBool() {
     return insecure_rand_ctx.randbool();
 }
 static inline std::vector<uint8_t> InsecureRandBytes(size_t len) {
     return insecure_rand_ctx.randbytes(len);
 }
 
 /**
  * Basic testing setup.
  * This just configures logging and chain parameters.
  */
 struct BasicTestingSetup {
     ECCVerifyHandle globalVerifyHandle;
 
     explicit BasicTestingSetup(
         const std::string &chainName = CBaseChainParams::MAIN);
     ~BasicTestingSetup();
 };
 
 /** Testing setup that configures a complete environment.
  * Included are data directory, coins database, script check threads setup.
  */
 class CConnman;
 class CNode;
 struct CConnmanTest {
     static void AddNode(CNode &node);
     static void ClearNodes();
 };
 
 class PeerLogicValidation;
 struct TestingSetup : public BasicTestingSetup {
     fs::path pathTemp;
     boost::thread_group threadGroup;
     CConnman *connman;
     CScheduler scheduler;
     std::unique_ptr<PeerLogicValidation> peerLogic;
 
     explicit TestingSetup(
         const std::string &chainName = CBaseChainParams::MAIN);
     ~TestingSetup();
 };
 
 class CBlock;
 class CMutableTransaction;
 class CScript;
 
 //
 // Testing fixture that pre-creates a
 // 100-block REGTEST-mode block chain
 //
 struct TestChain100Setup : public TestingSetup {
     TestChain100Setup();
 
     // Create a new block with just given transactions, coinbase paying to
     // scriptPubKey, and try to add it to the current chain.
     CBlock CreateAndProcessBlock(const std::vector<CMutableTransaction> &txns,
                                  const CScript &scriptPubKey);
 
     ~TestChain100Setup();
 
     // For convenience, coinbase transactions.
     std::vector<CTransaction> coinbaseTxns;
     // private/public key needed to spend coinbase transactions.
     CKey coinbaseKey;
 };
 
 class CTxMemPoolEntry;
 class CTxMemPool;
 
 struct TestMemPoolEntryHelper {
     // Default values
     Amount nFee;
     int64_t nTime;
     double dPriority;
     unsigned int nHeight;
     bool spendsCoinbase;
     unsigned int sigOpCost;
     LockPoints lp;
 
     TestMemPoolEntryHelper()
         : nFee(), nTime(0), dPriority(0.0), nHeight(1), spendsCoinbase(false),
           sigOpCost(4) {}
 
     CTxMemPoolEntry FromTx(const CMutableTransaction &tx,
                            CTxMemPool *pool = nullptr);
     CTxMemPoolEntry FromTx(const CTransaction &tx, CTxMemPool *pool = nullptr);
 
     // Change the default value
     TestMemPoolEntryHelper &Fee(Amount _fee) {
         nFee = _fee;
         return *this;
     }
     TestMemPoolEntryHelper &Time(int64_t _time) {
         nTime = _time;
         return *this;
     }
     TestMemPoolEntryHelper &Priority(double _priority) {
         dPriority = _priority;
         return *this;
     }
     TestMemPoolEntryHelper &Height(unsigned int _height) {
         nHeight = _height;
         return *this;
     }
     TestMemPoolEntryHelper &SpendsCoinbase(bool _flag) {
         spendsCoinbase = _flag;
         return *this;
     }
     TestMemPoolEntryHelper &SigOpsCost(unsigned int _sigopsCost) {
         sigOpCost = _sigopsCost;
         return *this;
     }
 };
 #endif