Binary package “libgtkd-3-dev” in ubuntu focal

GTK+ graphical user interface library - development files for D

 GTK+ is a multi-platform toolkit for creating graphical user interfaces.
 Offering a complete set of widgets, GTK+ is suitable for projects ranging
 from small one-off tools to complete application suites.
 .
 This package contains development files needed to write applications in
 the D programming language that use GTK+.