adding in simple button

.gitignore

@@ -1,3 +1,38 @@
 build/
 
 *.so
+
+.cache/
+
+# Prerequisites
+*.d
+
+# Compiled Object files
+*.slo
+*.lo
+*.o
+*.obj
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Compiled Dynamic libraries
+*.so
+*.dylib
+*.dll
+
+# Fortran module files
+*.mod
+*.smod
+
+# Compiled Static libraries
+*.lai
+*.la
+*.a
+*.lib
+
+# Executables
+*.exe
+*.out
+*.app

src/main.cpp

@@ -1,4 +1,6 @@
+#include "gtkmm/button.h"
 #include <gtkmm.h>
+#include <iostream>
 
 class MyWindow : public Gtk::Window {
 public:
@@ -7,7 +9,14 @@ public:
 
 MyWindow::MyWindow() {
   set_title("Basic application");
+
+  Gtk::Button button("Hello World");
+  button.signal_clicked().connect([] { std::cout << "Hello World\n"; });
+  button.set_label("Hello World");
+
   set_default_size(800, 450);
+
+  set_child(button);
 }
 
 int main(int argc, char **argv) {