Hi, You can't, sorry.
Preprocessor in vala is simplistic, and doesn't intend to be more complex. https://wiki.gnome.org/Projects/Vala/FAQ#Does_Vala_have_a_preprocessor.3F But, you can define a symbol using valac command. You will find plenty of examples to do it with autotools, for meson you can get inspiration from the Gnome repository. static int main(string[] args) { #if GTK_3_22 stdout.puts("GTK_3_22\n"); #else stdout.puts("other\n"); #endif return 0; } $ valac main.vala && ./main others $ valac -D GTK_3_22 main.vala && ./main GTK_3_22 Or you can use vala code checking the actual version. using Gtk; static int main(string[] args) { stdout.printf("Gtk: %d.%d.%d\n", Gtk.MAJOR_VERSION, Gtk.MINOR_VERSION, Gtk.MICRO_VERSION); return 0; } $ valac --pkg gtk+-3.0 main.vala && ./main Gtk: 3.22.10 Hope I helped, Luc. Le mer. 25 avr. 2018 à 23:35, rastersoft <ras...@rastersoft.com> a écrit : > Hello: > > I want to do this conditional compilation in my code: > > #ifGTK_CHECK_VERSION(3, 22, 0) > this.menu.popup_at_pointer(event); > #else > this.menu.popup(null, null, null, 2, Gtk.get_current_event_time()); > #endif Unfortunately, GTK_CHECK_VERSION doesn't work in Vala. Is there > an alternative to do that in Vala? Thanks. > _______________________________________________ > vala-list mailing list > vala-list@gnome.org > https://mail.gnome.org/mailman/listinfo/vala-list > _______________________________________________ vala-list mailing list vala-list@gnome.org https://mail.gnome.org/mailman/listinfo/vala-list