Replace wxEXPLICIT with the 'explicit' keyword

See #17655.

include/wx/private/addremovectrl.h

@@ -24,9 +24,9 @@ public:
     // class is supposed to create the buttons and layout everything.
     //
     // Takes ownership of the adaptor pointer.
-    wxEXPLICIT wxAddRemoveImplBase(wxAddRemoveAdaptor* adaptor,
-                                   wxAddRemoveCtrl* WXUNUSED(parent),
-                                   wxWindow* ctrlItems)
+    explicit wxAddRemoveImplBase(wxAddRemoveAdaptor* adaptor,
+                                 wxAddRemoveCtrl* WXUNUSED(parent),
+                                 wxWindow* ctrlItems)
         : m_adaptor(adaptor)
     {
         ctrlItems->Bind(wxEVT_CHAR, &wxAddRemoveImplBase::OnChar, this);
@@ -105,9 +105,9 @@ private:
 class wxAddRemoveImplWithButtons : public wxAddRemoveImplBase
 {
 public:
-    wxEXPLICIT wxAddRemoveImplWithButtons(wxAddRemoveAdaptor* adaptor,
-                                          wxAddRemoveCtrl* parent,
-                                          wxWindow* ctrlItems)
+    explicit wxAddRemoveImplWithButtons(wxAddRemoveAdaptor* adaptor,
+                                        wxAddRemoveCtrl* parent,
+                                        wxWindow* ctrlItems)
         : wxAddRemoveImplBase(adaptor, parent, ctrlItems)
     {
         m_btnAdd =

include/wx/private/fdioeventloopsourcehandler.h

@@ -19,7 +19,7 @@
 class wxFDIOEventLoopSourceHandler : public wxFDIOHandler
 {
 public:
-    wxEXPLICIT wxFDIOEventLoopSourceHandler(wxEventLoopSourceHandler* handler)
+    explicit wxFDIOEventLoopSourceHandler(wxEventLoopSourceHandler* handler)
         : m_handler(handler)
     {
     }