Merge #19844: remove usage of boost::bind

e36f802 lint: add C++ code linter (fanquake)
c4be50f remove usage of boost::bind (fanquake)

Pull request description:

  `boost::bind` usage was removed in #13743. However a new usage snuck in as
  part of 2bc4c3e (#15225).

ACKs for top commit:
  hebasto:
    ACK e36f802
  practicalswift:
    ACK e36f802 -- patch looks correct

Tree-SHA512: 2b0387c5443c184bcbf7df4849db1ed1296ff82c7b4ff0aff18334a400e56a472a972d18234d3866531a088d7a8da64688e58dc9f15daaad4048697c759d55ce

Author: fanquake

src/qt/walletmodel.cpp

@@ -413,7 +413,7 @@ void WalletModel::subscribeToCoreSignals()
     m_handler_transaction_changed = m_wallet->handleTransactionChanged(std::bind(NotifyTransactionChanged, this, std::placeholders::_1, std::placeholders::_2));
     m_handler_show_progress = m_wallet->handleShowProgress(std::bind(ShowProgress, this, std::placeholders::_1, std::placeholders::_2));
     m_handler_watch_only_changed = m_wallet->handleWatchOnlyChanged(std::bind(NotifyWatchonlyChanged, this, std::placeholders::_1));
-    m_handler_can_get_addrs_changed = m_wallet->handleCanGetAddressesChanged(boost::bind(NotifyCanGetAddressesChanged, this));
+    m_handler_can_get_addrs_changed = m_wallet->handleCanGetAddressesChanged(std::bind(NotifyCanGetAddressesChanged, this));
 }
 
 void WalletModel::unsubscribeFromCoreSignals()

test/lint/lint-cpp.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+#
+# 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.
+#
+# Check for various C++ code patterns we want to avoid.
+
+export LC_ALL=C
+
+EXIT_CODE=0
+
+OUTPUT=$(git grep -E "boost::bind\(" -- "*.cpp" "*.h")
+if [[ ${OUTPUT} != "" ]]; then
+    echo "Use of boost::bind detected. Use std::bind instead."
+    echo
+    echo "${OUTPUT}"
+    EXIT_CODE=1
+fi
+
+exit ${EXIT_CODE}