qt,cpp: Consistently use nullptr and override

* lang/cpp/src/Makefile.am, lang/qt/src/Makefile.am (AM_CPPFLAGS):
Add suggest-override and zero-as-null-pointer-constant warnings.

* lang/cpp/src/*, lang/qt/src/*: Consistenly use nullptr and override.

--
This was especially important for the headers so that downstream
users of GpgME++ or QGpgME do not get flooded by warnings if
they have these warnings enabled.

It also improves compiler errors/warnings in case of accidental
mistakes.

1 files changed, 5 insertions, 5 deletions

diff --git a/lang/cpp/src/trustitem.cpp b/lang/cpp/src/trustitem.cpp
index c29c0f41..4302f657 100644
--- a/lang/cpp/src/trustitem.cpp
+++ b/lang/cpp/src/trustitem.cpp
@@ -67,7 +67,7 @@ TrustItem::~TrustItem()
     if (d->item) {
         gpgme_trust_item_unref(d->item);
     }
-    delete d; d = 0;
+    delete d; d = nullptr;
 }
 
 bool TrustItem::isNull() const
@@ -82,22 +82,22 @@ gpgme_trust_item_t TrustItem::impl() const
 
 const char *TrustItem::keyID() const
 {
-    return d->item ? d->item->keyid : 0 ;
+    return d->item ? d->item->keyid : nullptr ;
 }
 
 const char *TrustItem::userID() const
 {
-    return d->item ? d->item->name : 0 ;
+    return d->item ? d->item->name : nullptr ;
 }
 
 const char *TrustItem::ownerTrustAsString() const
 {
-    return d->item ? d->item->owner_trust : 0 ;
+    return d->item ? d->item->owner_trust : nullptr ;
 }
 
 const char *TrustItem::validityAsString() const
 {
-    return d->item ? d->item->validity : 0 ;
+    return d->item ? d->item->validity : nullptr ;
 }
 
 int TrustItem::trustLevel() const