Switch from the c++11 standard to the c++17 standard.

Fix two new warnings that arise from this change.  One is to add
parentheses, and the other is that writing a custom 'operator='
function requires writing a custom copy constructor function.

mythplugins/settings.pro

@@ -1,6 +1,5 @@
 CONFIG += $$CCONFIG
-# enable C++11 support, QT5.7 will be based on C++11 anyway
-CONFIG += c++11
+CONFIG += c++17
 
 LIBVERSION = 32
 

mythtv/configure

@@ -11,6 +11,8 @@
 LC_ALL=C
 export LC_ALL
 
+CPP_STANDARD=c++17
+
 # make sure we are running under a compatible shell
 # try to make this part work with most shells
 
@@ -4570,7 +4572,7 @@ fi
 
 add_cppflags -D_ISOC99_SOURCE -D_POSIX_C_SOURCE=200112
 #add_cxxflags -D__STDC_CONSTANT_MACROS
-check_cxxflags -std=c++11 || check_cxxflags -std=c++0x
+check_cxxflags -std=$CPP_STANDARD -faligned-new
 
 # some compilers silently accept -std=c11, so we also need to check that the
 # version macro is defined properly
@@ -6918,7 +6920,6 @@ elif enabled icpc; then
     # 10181: ignore warning about -fomit-frame-pointer being ignored
     # 13200: ignore EMMS instruction required, RTjpegN.cpp does the right thing
     check_cxxflags -wd177,192,592,913,10181,13200
-    check_cxxflags -std=c++11
 elif enabled clangxx; then
     # The constant-logical-operand only gives use false positives
     # for constant logical operands meant to be optimized away.
@@ -7478,6 +7479,7 @@ echo "libdav1d (AV1)            ${libdav1d-no}"
 echo ""
 
 echo "# Compilation Options"
+echo "C++ standard supported    ${CPP_STANDARD}"
 echo "Enforce c++11 nullptr     ${enforce_nullptr-no}"
 echo "Enforce shadowed vars     ${enforce_wshadow-no}"
 echo ""

mythtv/libs/libmyth/audio/eldutils.cpp

@@ -158,6 +158,11 @@ ELD::ELD(const char *buf, int size)
     update_eld(buf, size);
 }
 
+ELD::ELD(const ELD &rhs)
+{
+    m_e = rhs.m_e;
+}
+
 ELD::ELD()
 {
     m_e.formats = 0LL;

mythtv/libs/libmyth/audio/eldutils.h

@@ -40,6 +40,7 @@ class MPUBLIC ELD
 {
   public:
     ELD(const char *buf, int size);
+    ELD(const ELD&);
     ELD();
     ~ELD()= default;
     ELD& operator=(const ELD& /*rhs*/);

mythtv/libs/libmythbase/platforms/mythpowerdbus.cpp

@@ -126,8 +126,10 @@ void MythPowerDBus::Init(void)
     {
         QDBusReply<QList<QDBusObjectPath> > devices = m_upowerInterface->call(QLatin1String("EnumerateDevices"));
         if (devices.isValid())
+        {
             foreach (QDBusObjectPath device, devices.value())
                 DeviceAdded(device);
+        }
 
         if (!m_bus.connect(UPOWER_SERVICE, UPOWER_PATH, UPOWER_SERVICE, "Changed", this, SLOT(Changed())))
         {

mythtv/programs/mythfrontend/videofileassoc.cpp

@@ -89,19 +89,19 @@ namespace
         void SetDefault(bool yes_or_no)
         {
             assign_if_changed_notify(m_fa.use_default, yes_or_no, this,
-                    std::mem_fun(&FileAssociationWrap::SetChanged));
+                    std::mem_fn(&FileAssociationWrap::SetChanged));
         }
 
         void SetIgnore(bool yes_or_no)
         {
             assign_if_changed_notify(m_fa.ignore, yes_or_no, this,
-                    std::mem_fun(&FileAssociationWrap::SetChanged));
+                    std::mem_fn(&FileAssociationWrap::SetChanged));
         }
 
         void SetCommand(const QString &new_command)
         {
             assign_if_changed_notify(m_fa.playcommand, new_command, this,
-                    std::mem_fun(&FileAssociationWrap::SetChanged));
+                    std::mem_fn(&FileAssociationWrap::SetChanged));
         }
 
       private:

mythtv/settings.pro

@@ -25,8 +25,7 @@ win32-msvc* {
 }
 
 CONFIG += $$CCONFIG
-# enable C++11 support, QT5.7 will be based on C++11 anyway
-CONFIG += c++11
+CONFIG += c++17
 
 defineReplace(avLibName) {
         NAME = $$1