compile.sh

g++ `pkg-config --cflags --libs gtkmm-3.0` -o ./thing ./thing.cpp

output.log

/tmp/ccpEFTP9.o: In function `main':
ui.cpp:(.text+0x26): undefined reference to `Glib::ustring::ustring(char const*)'
ui.cpp:(.text+0x4a): undefined reference to `Gtk::Application::create(int&, char**&, Glib::ustring const&, Gio::ApplicationFlags)'
ui.cpp:(.text+0x56): undefined reference to `Glib::ustring::~ustring()'
ui.cpp:(.text+0x65): undefined reference to `Gtk::ApplicationWindow::ApplicationWindow()'
ui.cpp:(.text+0x83): undefined reference to `Gtk::Application::run(Gtk::Window&)'
ui.cpp:(.text+0x94): undefined reference to `Gtk::ApplicationWindow::~ApplicationWindow()'
ui.cpp:(.text+0xbb): undefined reference to `Glib::ustring::~ustring()'
ui.cpp:(.text+0xd8): undefined reference to `Gtk::ApplicationWindow::~ApplicationWindow()'
/tmp/ccpEFTP9.o: In function `__static_initialization_and_destruction_0(int, int)':
ui.cpp:(.text+0x128): undefined reference to `Glib::ustring::ustring(char const*)'
ui.cpp:(.text+0x12d): undefined reference to `Glib::ustring::~ustring()'
ui.cpp:(.text+0x14e): undefined reference to `Glib::ustring::ustring(char const*)'
ui.cpp:(.text+0x153): undefined reference to `Glib::ustring::~ustring()'
ui.cpp:(.text+0x174): undefined reference to `Glib::ustring::ustring(char const*)'
ui.cpp:(.text+0x179): undefined reference to `Glib::ustring::~ustring()'
ui.cpp:(.text+0x19a): undefined reference to `Glib::ustring::ustring(char const*)'
ui.cpp:(.text+0x19f): undefined reference to `Glib::ustring::~ustring()'
ui.cpp:(.text+0x1c0): undefined reference to `Glib::ustring::ustring(char const*)'
ui.cpp:(.text+0x1c5): undefined reference to `Glib::ustring::~ustring()'
ui.cpp:(.text+0x1e6): undefined reference to `Glib::ustring::ustring(char const*)'
ui.cpp:(.text+0x1eb): undefined reference to `Glib::ustring::~ustring()'
ui.cpp:(.text+0x20c): undefined reference to `Glib::ustring::ustring(char const*)'
ui.cpp:(.text+0x211): undefined reference to `Glib::ustring::~ustring()'
collect2: ld returned 1 exit status

thing.cpp

#include <gtkmm.h>

int main(int argc, char *argv[])
{
  Glib::RefPtr<Gtk::Application> app =
    Gtk::Application::create(argc, argv,
      "org.gtkmm.examples.base");

  Gtk::ApplicationWindow window;

  return app->run(window);
}