Merge #21366: refactor: replace util::Ref with std::any (C++17)

916ab0195d remove unused class util::Ref and its unit test (Sebastian Falbesoner)
8dbb87a393 refactor: replace util::Ref by std::any (C++17) (Sebastian Falbesoner)
95cccf8a4b util: introduce helper AnyPtr to access std::any instances (Sebastian Falbesoner)

Pull request description:

  As described in `util/ref.h`: "_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**_". For accessing the contained object of a `std::any` instance, a helper template function `AnyPtr` is introduced (thanks to ryanofsky).

ACKs for top commit:
  hebasto:
    re-ACK 916ab0195d, with command
  ryanofsky:
    Code review ACK 916ab0195d. Changes since last review: rebase and replacing types with `auto`. I might have used `const auto*` and `auto*` instead of plain `auto` because I think the qualifiers are useful, but this is all good.

Tree-SHA512: fe2c3e4f5726f8ad40c61128339bb24ad11d2c261f71f7b934b1efe3e3279df14046452b0d9b566917ef61d5c7e0fd96ccbf35ff810357e305710f5002c27d47

src/Makefile.am

@@ -243,7 +243,6 @@ BITCOIN_CORE_H = \
   util/moneystr.h \
   util/rbf.h \
   util/readwritefile.h \
-  util/ref.h \
   util/settings.h \
   util/sock.h \
   util/spanparsing.h \

src/Makefile.test.include

@@ -112,7 +112,6 @@ BITCOIN_TESTS =\
   test/prevector_tests.cpp \
   test/raii_event_tests.cpp \
   test/random_tests.cpp \
-  test/ref_tests.cpp \
   test/reverselock_tests.cpp \
   test/rpc_tests.cpp \
   test/sanity_tests.cpp \

src/bitcoind.cpp

@@ -16,7 +16,7 @@
 #include <node/ui_interface.h>
 #include <noui.h>
 #include <shutdown.h>
-#include <util/ref.h>
+#include <util/check.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <util/threadnames.h>
@@ -24,6 +24,7 @@
 #include <util/translation.h>
 #include <util/url.h>
 
+#include <any>
 #include <functional>
 #include <optional>
 
@@ -142,7 +143,7 @@ static bool AppInit(int argc, char* argv[])
     // end, which is interpreted as failure to start.
     TokenPipeEnd daemon_ep;
 #endif
-    util::Ref context{node};
+    std::any context{&node};
     try
     {
         if (!CheckDataDirOption()) {

src/httprpc.cpp

@@ -144,7 +144,7 @@ static bool RPCAuthorized(const std::string& strAuth, std::string& strAuthUserna
     return multiUserAuthorized(strUserPass);
 }
 
-static bool HTTPReq_JSONRPC(const util::Ref& context, HTTPRequest* req)
+static bool HTTPReq_JSONRPC(const std::any& context, HTTPRequest* req)
 {
     // JSONRPC handles only POST
     if (req->GetRequestMethod() != HTTPRequest::POST) {
@@ -288,7 +288,7 @@ static bool InitRPCAuthentication()
     return true;
 }
 
-bool StartHTTPRPC(const util::Ref& context)
+bool StartHTTPRPC(const std::any& context)
 {
     LogPrint(BCLog::RPC, "Starting HTTP RPC server\n");
     if (!InitRPCAuthentication())

src/httprpc.h

@@ -5,14 +5,12 @@
 #ifndef BITCOIN_HTTPRPC_H
 #define BITCOIN_HTTPRPC_H
 
-namespace util {
-class Ref;
-} // namespace util
+#include <any>
 
 /** Start HTTP RPC subsystem.
  * Precondition; HTTP and RPC has been started.
  */
-bool StartHTTPRPC(const util::Ref& context);
+bool StartHTTPRPC(const std::any& context);
 /** Interrupt HTTP RPC subsystem.
  */
 void InterruptHTTPRPC();
@@ -24,7 +22,7 @@ void StopHTTPRPC();
 /** Start HTTP REST subsystem.
  * Precondition; HTTP and RPC has been started.
  */
-void StartREST(const util::Ref& context);
+void StartREST(const std::any& context);
 /** Interrupt RPC REST subsystem.
  */
 void InterruptREST();

src/init.cpp

@@ -788,7 +788,7 @@ static bool InitSanityCheck()
     return true;
 }
 
-static bool AppInitServers(const util::Ref& context, NodeContext& node)
+static bool AppInitServers(const std::any& context, NodeContext& node)
 {
     const ArgsManager& args = *Assert(node.args);
     RPCServer::OnStarted(&OnRPCStarted);
@@ -1277,7 +1277,7 @@ bool AppInitInterfaces(NodeContext& node)
     return true;
 }
 
-bool AppInitMain(const util::Ref& context, NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
+bool AppInitMain(const std::any& context, NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 {
     const ArgsManager& args = *Assert(node.args);
     const CChainParams& chainparams = Params();

src/init.h

@@ -6,6 +6,7 @@
 #ifndef BITCOIN_INIT_H
 #define BITCOIN_INIT_H
 
+#include <any>
 #include <memory>
 #include <string>
 
@@ -22,9 +23,6 @@ struct BlockAndHeaderTipInfo;
 namespace boost {
 class thread_group;
 } // namespace boost
-namespace util {
-class Ref;
-} // namespace util
 
 /** Interrupt threads */
 void Interrupt(NodeContext& node);
@@ -66,7 +64,7 @@ bool AppInitInterfaces(NodeContext& node);
  * @note This should only be done after daemonization. Call Shutdown() if this function fails.
  * @pre Parameters should be parsed and config file should be read, AppInitLockDataDirectory should have been called.
  */
-bool AppInitMain(const util::Ref& context, NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info = nullptr);
+bool AppInitMain(const std::any& context, NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info = nullptr);
 
 /**
  * Register all arguments with the ArgsManager

src/node/interfaces.cpp

@@ -38,7 +38,6 @@
 #include <uint256.h>
 #include <univalue.h>
 #include <util/check.h>
-#include <util/ref.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <validation.h>
@@ -49,6 +48,7 @@
 #include <config/bitcoin-config.h>
 #endif
 
+#include <any>
 #include <memory>
 #include <optional>
 #include <utility>
@@ -298,13 +298,13 @@ public:
     {
         m_context = context;
         if (context) {
-            m_context_ref.Set(*context);
+            m_context_ref = context;
         } else {
-            m_context_ref.Clear();
+            m_context_ref.reset();
         }
     }
     NodeContext* m_context{nullptr};
-    util::Ref m_context_ref;
+    std::any m_context_ref;
 };
 
 bool FillBlock(const CBlockIndex* index, const FoundBlock& block, UniqueLock<RecursiveMutex>& lock, const CChain& active)

src/rest.cpp

@@ -18,10 +18,12 @@
 #include <sync.h>
 #include <txmempool.h>
 #include <util/check.h>
-#include <util/ref.h>
+#include <util/system.h>
 #include <validation.h>
 #include <version.h>
 
+#include <any>
+
 #include <boost/algorithm/string.hpp>
 
 #include <univalue.h>
@@ -73,10 +75,10 @@ static bool RESTERR(HTTPRequest* req, enum HTTPStatusCode status, std::string me
  *                  context is not found.
  * @returns         Pointer to the node context or nullptr if not found.
  */
-static NodeContext* GetNodeContext(const util::Ref& context, HTTPRequest* req)
+static NodeContext* GetNodeContext(const std::any& context, HTTPRequest* req)
 {
-    NodeContext* node = context.Has<NodeContext>() ? &context.Get<NodeContext>() : nullptr;
-    if (!node) {
+    auto node_context = util::AnyPtr<NodeContext>(context);
+    if (!node_context) {
         RESTERR(req, HTTP_INTERNAL_SERVER_ERROR,
                 strprintf("%s:%d (%s)\n"
                           "Internal bug detected: Node context not found!\n"
@@ -84,7 +86,7 @@ static NodeContext* GetNodeContext(const util::Ref& context, HTTPRequest* req)
                           __FILE__, __LINE__, __func__, PACKAGE_BUGREPORT));
         return nullptr;
     }
-    return node;
+    return node_context;
 }
 
 /**
@@ -94,14 +96,14 @@ static NodeContext* GetNodeContext(const util::Ref& context, HTTPRequest* req)
  *                 context mempool is not found.
  * @returns        Pointer to the mempool or nullptr if no mempool found.
  */
-static CTxMemPool* GetMemPool(const util::Ref& context, HTTPRequest* req)
+static CTxMemPool* GetMemPool(const std::any& context, HTTPRequest* req)
 {
-    NodeContext* node = context.Has<NodeContext>() ? &context.Get<NodeContext>() : nullptr;
-    if (!node || !node->mempool) {
+    auto node_context = util::AnyPtr<NodeContext>(context);
+    if (!node_context || !node_context->mempool) {
         RESTERR(req, HTTP_NOT_FOUND, "Mempool disabled or instance not found");
         return nullptr;
     }
-    return node->mempool.get();
+    return node_context->mempool.get();
 }
 
 static RetFormat ParseDataFormat(std::string& param, const std::string& strReq)
@@ -151,7 +153,7 @@ static bool CheckWarmup(HTTPRequest* req)
     return true;
 }
 
-static bool rest_headers(const util::Ref& context,
+static bool rest_headers(const std::any& context,
                          HTTPRequest* req,
                          const std::string& strURIPart)
 {
@@ -293,12 +295,12 @@ static bool rest_block(HTTPRequest* req,
     }
 }
 
-static bool rest_block_extended(const util::Ref& context, HTTPRequest* req, const std::string& strURIPart)
+static bool rest_block_extended(const std::any& context, HTTPRequest* req, const std::string& strURIPart)
 {
     return rest_block(req, strURIPart, true);
 }
 
-static bool rest_block_notxdetails(const util::Ref& context, HTTPRequest* req, const std::string& strURIPart)
+static bool rest_block_notxdetails(const std::any& context, HTTPRequest* req, const std::string& strURIPart)
 {
     return rest_block(req, strURIPart, false);
 }
@@ -306,7 +308,7 @@ static bool rest_block_notxdetails(const util::Ref& context, HTTPRequest* req, c
 // A bit of a hack - dependency on a function defined in rpc/blockchain.cpp
 RPCHelpMan getblockchaininfo();
 
-static bool rest_chaininfo(const util::Ref& context, HTTPRequest* req, const std::string& strURIPart)
+static bool rest_chaininfo(const std::any& context, HTTPRequest* req, const std::string& strURIPart)
 {
     if (!CheckWarmup(req))
         return false;
@@ -329,7 +331,7 @@ static bool rest_chaininfo(const util::Ref& context, HTTPRequest* req, const std
     }
 }
 
-static bool rest_mempool_info(const util::Ref& context, HTTPRequest* req, const std::string& strURIPart)
+static bool rest_mempool_info(const std::any& context, HTTPRequest* req, const std::string& strURIPart)
 {
     if (!CheckWarmup(req))
         return false;
@@ -353,7 +355,7 @@ static bool rest_mempool_info(const util::Ref& context, HTTPRequest* req, const
     }
 }
 
-static bool rest_mempool_contents(const util::Ref& context, HTTPRequest* req, const std::string& strURIPart)
+static bool rest_mempool_contents(const std::any& context, HTTPRequest* req, const std::string& strURIPart)
 {
     if (!CheckWarmup(req)) return false;
     const CTxMemPool* mempool = GetMemPool(context, req);
@@ -376,7 +378,7 @@ static bool rest_mempool_contents(const util::Ref& context, HTTPRequest* req, co
     }
 }
 
-static bool rest_tx(const util::Ref& context, HTTPRequest* req, const std::string& strURIPart)
+static bool rest_tx(const std::any& context, HTTPRequest* req, const std::string& strURIPart)
 {
     if (!CheckWarmup(req))
         return false;
@@ -435,7 +437,7 @@ static bool rest_tx(const util::Ref& context, HTTPRequest* req, const std::strin
     }
 }
 
-static bool rest_getutxos(const util::Ref& context, HTTPRequest* req, const std::string& strURIPart)
+static bool rest_getutxos(const std::any& context, HTTPRequest* req, const std::string& strURIPart)
 {
     if (!CheckWarmup(req))
         return false;
@@ -621,7 +623,7 @@ static bool rest_getutxos(const util::Ref& context, HTTPRequest* req, const std:
     }
 }
 
-static bool rest_blockhash_by_height(const util::Ref& context, HTTPRequest* req,
+static bool rest_blockhash_by_height(const std::any& context, HTTPRequest* req,
                        const std::string& str_uri_part)
 {
     if (!CheckWarmup(req)) return false;
@@ -669,7 +671,7 @@ static bool rest_blockhash_by_height(const util::Ref& context, HTTPRequest* req,
 
 static const struct {
     const char* prefix;
-    bool (*handler)(const util::Ref& context, HTTPRequest* req, const std::string& strReq);
+    bool (*handler)(const std::any& context, HTTPRequest* req, const std::string& strReq);
 } uri_prefixes[] = {
       {"/rest/tx/", rest_tx},
       {"/rest/block/notxdetails/", rest_block_notxdetails},
@@ -682,7 +684,7 @@ static const struct {
       {"/rest/blockhashbyheight/", rest_blockhash_by_height},
 };
 
-void StartREST(const util::Ref& context)
+void StartREST(const std::any& context)
 {
     for (const auto& up : uri_prefixes) {
         auto handler = [&context, up](HTTPRequest* req, const std::string& prefix) { return up.handler(context, req, prefix); };

src/rpc/blockchain.cpp

@@ -30,7 +30,6 @@
 #include <txdb.h>
 #include <txmempool.h>
 #include <undo.h>
-#include <util/ref.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <util/translation.h>
@@ -56,15 +55,16 @@ static Mutex cs_blockchange;
 static std::condition_variable cond_blockchange;
 static CUpdatedBlock latestblock GUARDED_BY(cs_blockchange);
 
-NodeContext& EnsureNodeContext(const util::Ref& context)
+NodeContext& EnsureNodeContext(const std::any& context)
 {
-    if (!context.Has<NodeContext>()) {
+    auto node_context = util::AnyPtr<NodeContext>(context);
+    if (!node_context) {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Node context not found");
     }
-    return context.Get<NodeContext>();
+    return *node_context;
 }
 
-CTxMemPool& EnsureMemPool(const util::Ref& context)
+CTxMemPool& EnsureMemPool(const std::any& context)
 {
     const NodeContext& node = EnsureNodeContext(context);
     if (!node.mempool) {
@@ -73,7 +73,7 @@ CTxMemPool& EnsureMemPool(const util::Ref& context)
     return *node.mempool;
 }
 
-ChainstateManager& EnsureChainman(const util::Ref& context)
+ChainstateManager& EnsureChainman(const std::any& context)
 {
     const NodeContext& node = EnsureNodeContext(context);
     if (!node.chainman) {
@@ -82,7 +82,7 @@ ChainstateManager& EnsureChainman(const util::Ref& context)
     return *node.chainman;
 }
 
-CBlockPolicyEstimator& EnsureFeeEstimator(const util::Ref& context)
+CBlockPolicyEstimator& EnsureFeeEstimator(const std::any& context)
 {
     NodeContext& node = EnsureNodeContext(context);
     if (!node.fee_estimator) {

src/rpc/blockchain.h

@@ -10,6 +10,7 @@
 #include <streams.h>
 #include <sync.h>
 
+#include <any>
 #include <stdint.h>
 #include <vector>
 
@@ -23,9 +24,6 @@ class CTxMemPool;
 class ChainstateManager;
 class UniValue;
 struct NodeContext;
-namespace util {
-class Ref;
-} // namespace util
 
 static constexpr int NUM_GETBLOCKSTATS_PERCENTILES = 5;
 
@@ -58,10 +56,10 @@ void CalculatePercentilesByWeight(CAmount result[NUM_GETBLOCKSTATS_PERCENTILES],
 void ScriptPubKeyToUniv(const CScript& scriptPubKey, UniValue& out, bool fIncludeHex);
 void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry, bool include_hex = true, int serialize_flags = 0, const CTxUndo* txundo = nullptr);
 
-NodeContext& EnsureNodeContext(const util::Ref& context);
-CTxMemPool& EnsureMemPool(const util::Ref& context);
-ChainstateManager& EnsureChainman(const util::Ref& context);
-CBlockPolicyEstimator& EnsureFeeEstimator(const util::Ref& context);
+NodeContext& EnsureNodeContext(const std::any& context);
+CTxMemPool& EnsureMemPool(const std::any& context);
+ChainstateManager& EnsureChainman(const std::any& context);
+CBlockPolicyEstimator& EnsureFeeEstimator(const std::any& context);
 
 /**
  * Helper to create UTXO snapshots given a chainstate and a file handle.

src/rpc/misc.cpp

@@ -17,7 +17,6 @@
 #include <script/descriptor.h>
 #include <util/check.h>
 #include <util/message.h> // For MessageSign(), MessageVerify()
-#include <util/ref.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 
@@ -391,8 +390,9 @@ static RPCHelpMan setmocktime()
         throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Mocktime can not be negative: %s.", time));
     }
     SetMockTime(time);
-    if (request.context.Has<NodeContext>()) {
-        for (const auto& chain_client : request.context.Get<NodeContext>().chain_clients) {
+    auto node_context = util::AnyPtr<NodeContext>(request.context);
+    if (node_context) {
+        for (const auto& chain_client : node_context->chain_clients) {
             chain_client->setMockTime(time);
         }
     }
@@ -424,11 +424,11 @@ static RPCHelpMan mockscheduler()
         throw std::runtime_error("delta_time must be between 1 and 3600 seconds (1 hr)");
     }
 
+    auto node_context = util::AnyPtr<NodeContext>(request.context);
     // protect against null pointer dereference
-    CHECK_NONFATAL(request.context.Has<NodeContext>());
-    NodeContext& node = request.context.Get<NodeContext>();
-    CHECK_NONFATAL(node.scheduler);
-    node.scheduler->MockForward(std::chrono::seconds(delta_seconds));
+    CHECK_NONFATAL(node_context);
+    CHECK_NONFATAL(node_context->scheduler);
+    node_context->scheduler->MockForward(std::chrono::seconds(delta_seconds));
 
     return NullUniValue;
 },

src/rpc/request.h

@@ -6,14 +6,11 @@
 #ifndef BITCOIN_RPC_REQUEST_H
 #define BITCOIN_RPC_REQUEST_H
 
+#include <any>
 #include <string>
 
 #include <univalue.h>
 
-namespace util {
-class Ref;
-} // namespace util
-
 UniValue JSONRPCRequestObj(const std::string& strMethod, const UniValue& params, const UniValue& id);
 UniValue JSONRPCReplyObj(const UniValue& result, const UniValue& error, const UniValue& id);
 std::string JSONRPCReply(const UniValue& result, const UniValue& error, const UniValue& id);
@@ -38,14 +35,14 @@ public:
     std::string URI;
     std::string authUser;
     std::string peerAddr;
-    const util::Ref& context;
+    const std::any& context;
 
-    explicit JSONRPCRequest(const util::Ref& context) : id(NullUniValue), params(NullUniValue), context(context) {}
+    explicit JSONRPCRequest(const std::any& context) : id(NullUniValue), params(NullUniValue), context(context) {}
 
     //! Initializes request information from another request object and the
     //! given context. The implementation should be updated if any members are
     //! added or removed above.
-    JSONRPCRequest(const JSONRPCRequest& other, const util::Ref& context)
+    JSONRPCRequest(const JSONRPCRequest& other, const std::any& context)
         : id(other.id), strMethod(other.strMethod), params(other.params), mode(other.mode), URI(other.URI),
           authUser(other.authUser), peerAddr(other.peerAddr), context(context)
     {

src/rpc/server.cpp

@@ -87,7 +87,7 @@ std::string CRPCTable::help(const std::string& strCommand, const JSONRPCRequest&
         vCommands.push_back(make_pair(entry.second.front()->category + entry.first, entry.second.front()));
     sort(vCommands.begin(), vCommands.end());
 
-    JSONRPCRequest jreq(helpreq);
+    JSONRPCRequest jreq = helpreq;
     jreq.mode = JSONRPCRequest::GET_HELP;
     jreq.params = UniValue();
 
@@ -494,7 +494,7 @@ std::vector<std::string> CRPCTable::listCommands() const
 
 UniValue CRPCTable::dumpArgMap(const JSONRPCRequest& args_request) const
 {
-    JSONRPCRequest request(args_request);
+    JSONRPCRequest request = args_request;
     request.mode = JSONRPCRequest::GET_ARGS;
 
     UniValue ret{UniValue::VARR};

src/test/ref_tests.cpp

@@ -1,33 +0,0 @@
-// 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()

src/test/rpc_tests.cpp

@@ -10,9 +10,10 @@
 #include <interfaces/chain.h>
 #include <node/context.h>
 #include <test/util/setup_common.h>
-#include <util/ref.h>
 #include <util/time.h>
 
+#include <any>
+
 #include <boost/algorithm/string.hpp>
 #include <boost/test/unit_test.hpp>
 
@@ -32,7 +33,7 @@ UniValue RPCTestingSetup::CallRPC(std::string args)
     boost::split(vArgs, args, boost::is_any_of(" \t"));
     std::string strMethod = vArgs[0];
     vArgs.erase(vArgs.begin());
-    util::Ref context{m_node};
+    std::any context{&m_node};
     JSONRPCRequest request(context);
     request.strMethod = strMethod;
     request.params = RPCConvertValues(strMethod, vArgs);

src/util/ref.h

@@ -1,38 +0,0 @@
-// 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

src/util/system.h

@@ -25,6 +25,7 @@
 #include <util/threadnames.h>
 #include <util/time.h>
 
+#include <any>
 #include <exception>
 #include <map>
 #include <optional>
@@ -500,6 +501,18 @@ inline void insert(std::set<TsetT>& dst, const Tsrc& src) {
     dst.insert(src.begin(), src.end());
 }
 
+/**
+ * Helper function to access the contained object of a std::any instance.
+ * Returns a pointer to the object if passed instance has a value and the type
+ * matches, nullptr otherwise.
+ */
+template<typename T>
+T* AnyPtr(const std::any& any) noexcept
+{
+    T* const* ptr = std::any_cast<T*>(&any);
+    return ptr ? *ptr : nullptr;
+}
+
 #ifdef WIN32
 class WinCmdLineArgs
 {

src/wallet/interfaces.cpp

@@ -15,7 +15,6 @@
 #include <sync.h>
 #include <uint256.h>
 #include <util/check.h>
-#include <util/ref.h>
 #include <util/system.h>
 #include <util/ui_change_type.h>
 #include <wallet/context.h>
@@ -515,7 +514,7 @@ public:
     {
         for (const CRPCCommand& command : GetWalletRPCCommands()) {
             m_rpc_commands.emplace_back(command.category, command.name, [this, &command](const JSONRPCRequest& request, UniValue& result, bool last_handler) {
-                return command.actor({request, m_context}, result, last_handler);
+                return command.actor({request, &m_context}, result, last_handler);
             }, command.argNames, command.unique_id);
             m_rpc_handlers.emplace_back(m_context.chain->handleRpc(m_rpc_commands.back()));
         }

src/wallet/rpcwallet.cpp

@@ -22,7 +22,6 @@
 #include <util/fees.h>
 #include <util/message.h> // For MessageSign()
 #include <util/moneystr.h>
-#include <util/ref.h>
 #include <util/string.h>
 #include <util/system.h>
 #include <util/translation.h>
@@ -124,12 +123,13 @@ void EnsureWalletIsUnlocked(const CWallet& wallet)
     }
 }
 
-WalletContext& EnsureWalletContext(const util::Ref& context)
+WalletContext& EnsureWalletContext(const std::any& context)
 {
-    if (!context.Has<WalletContext>()) {
+    auto wallet_context = util::AnyPtr<WalletContext>(context);
+    if (!wallet_context) {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Wallet context not found");
     }
-    return context.Get<WalletContext>();
+    return *wallet_context;
 }
 
 // also_create should only be set to true only when the RPC is expected to add things to a blank wallet and make it no longer blank

src/wallet/rpcwallet.h

@@ -7,6 +7,7 @@
 
 #include <span.h>
 
+#include <any>
 #include <memory>
 #include <string>
 #include <vector>
@@ -31,7 +32,7 @@ Span<const CRPCCommand> GetWalletRPCCommands();
 std::shared_ptr<CWallet> GetWalletForJSONRPCRequest(const JSONRPCRequest& request);
 
 void EnsureWalletIsUnlocked(const CWallet&);
-WalletContext& EnsureWalletContext(const util::Ref& context);
+WalletContext& EnsureWalletContext(const std::any& context);
 LegacyScriptPubKeyMan& EnsureLegacyScriptPubKeyMan(CWallet& wallet, bool also_create = false);
 
 RPCHelpMan getaddressinfo();

src/wallet/test/wallet_tests.cpp

@@ -4,6 +4,7 @@
 
 #include <wallet/wallet.h>
 
+#include <any>
 #include <future>
 #include <memory>
 #include <stdint.h>
@@ -15,7 +16,6 @@
 #include <rpc/server.h>
 #include <test/util/logging.h>
 #include <test/util/setup_common.h>
-#include <util/ref.h>
 #include <util/translation.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
@@ -213,7 +213,7 @@ BOOST_FIXTURE_TEST_CASE(importmulti_rescan, TestChain100Setup)
         key.pushKV("timestamp", newTip->GetBlockTimeMax() + TIMESTAMP_WINDOW + 1);
         key.pushKV("internal", UniValue(true));
         keys.push_back(key);
-        util::Ref context;
+        std::any context;
         JSONRPCRequest request(context);
         request.params.setArray();
         request.params.push_back(keys);
@@ -265,7 +265,7 @@ BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup)
             AddWallet(wallet);
             wallet->SetLastBlockProcessed(::ChainActive().Height(), ::ChainActive().Tip()->GetBlockHash());
         }
-        util::Ref context;
+        std::any context;
         JSONRPCRequest request(context);
         request.params.setArray();
         request.params.push_back(backup_file);
@@ -281,7 +281,7 @@ BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup)
         LOCK(wallet->cs_wallet);
         wallet->SetupLegacyScriptPubKeyMan();
 
-        util::Ref context;
+        std::any context;
         JSONRPCRequest request(context);
         request.params.setArray();
         request.params.push_back(backup_file);

test/lint/extended-lint-cppcheck.sh

@@ -57,7 +57,6 @@ IGNORED_WARNINGS=(
     "src/test/checkqueue_tests.cpp:.* Struct 'UniqueCheck' has a constructor with 1 argument that is not explicit."
     "src/test/fuzz/util.h:.* Class 'FuzzedFileProvider' has a constructor with 1 argument that is not explicit."
     "src/test/fuzz/util.h:.* Class 'FuzzedAutoFileProvider' has a constructor with 1 argument that is not explicit."
-    "src/util/ref.h:.* Class 'Ref' has a constructor with 1 argument that is not explicit."
     "src/wallet/db.h:.* Class 'BerkeleyEnvironment' has a constructor with 1 argument that is not explicit."
 )