Merge #13961: util: Replace boost::signals2 with std::function

ddddce0e46e73d4ca369f2ce9696231cc579e1f9 util: Replace boost::signals2 with std::function (MarcoFalke)

Pull request description:

  This removes the `#include <boost/signals2/signal.hpp>` from `util.h` (hopefully speeding up the build time and reducing the memory usage further after  #13634)

  The whole translation interface is replaced by a function `G_TRANSLATION_FUN` that is set to nullptr in units that don't need translation. (Thus only set in the gui)

Tree-SHA512: 087c717358bbed8bdb409463e225239d667f1ced381abb10e7cd31a41dcdd2cebe20b43c2ee86f0f8e55d53301f75e963f07421a99a7ff4c0cad2c6a375c5ab1

4 files changed, 11 insertions, 9 deletions

diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
index 85fb88d338..712d20b71e 100644
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -76,13 +76,10 @@ static void InitMessage(const std::string &message)
     LogPrintf("init message: %s\n", message);
 }
 
-/*
-   Translate string to current locale using Qt.
- */
-static std::string Translate(const char* psz)
-{
+/** Translate string to current locale using Qt. */
+const std::function<std::string(const char*)> G_TRANSLATION_FUN = [](const char* psz) {
     return QCoreApplication::translate("bitcoin-core", psz).toStdString();
-}
+};
 
 static QString GetLangTerritory()
 {
@@ -618,7 +615,6 @@ int main(int argc, char *argv[])
     // Now that QSettings are accessible, initialize translations
     QTranslator qtTranslatorBase, qtTranslator, translatorBase, translator;
     initTranslations(qtTranslatorBase, qtTranslator, translatorBase, translator);
-    translationInterface.Translate.connect(Translate);
 
     // Show help message immediately after parsing command-line options (for "-lang") and setting locale,
     // but before showing splash screen.
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index cefa9004ed..5321cd94fd 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -57,6 +57,8 @@
 #include <QUrlQuery>
 #include <QVBoxLayout>
 
+#include <boost/bind.hpp>
+
 const std::string BitcoinGUI::DEFAULT_UIPLATFORM =
 #if defined(Q_OS_MAC)
         "macosx"
diff --git a/src/qt/splashscreen.cpp b/src/qt/splashscreen.cpp
index e438d22919..0b111cc6d7 100644
--- a/src/qt/splashscreen.cpp
+++ b/src/qt/splashscreen.cpp
@@ -14,8 +14,8 @@
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
 #include <interfaces/wallet.h>
-#include <util.h>
 #include <ui_interface.h>
+#include <util.h>
 #include <version.h>
 
 #include <QApplication>
@@ -24,6 +24,8 @@
 #include <QPainter>
 #include <QRadialGradient>
 
+#include <boost/bind.hpp>
+
 SplashScreen::SplashScreen(interfaces::Node& node, Qt::WindowFlags f, const NetworkStyle *networkStyle) :
     QWidget(0, f), curAlignment(0), m_node(node)
 {
diff --git a/src/qt/transactiontablemodel.cpp b/src/qt/transactiontablemodel.cpp
index e379b70553..4fa941b630 100644
--- a/src/qt/transactiontablemodel.cpp
+++ b/src/qt/transactiontablemodel.cpp
@@ -16,10 +16,10 @@
 #include <core_io.h>
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
-#include <validation.h>
 #include <sync.h>
 #include <uint256.h>
 #include <util.h>
+#include <validation.h>
 
 #include <QColor>
 #include <QDateTime>
@@ -27,6 +27,8 @@
 #include <QIcon>
 #include <QList>
 
+#include <boost/bind.hpp>
+
 // Amount column is right-aligned it contains numbers
 static int column_alignments[] = {
         Qt::AlignLeft|Qt::AlignVCenter, /* status */