dev-cpp/gtkmm: add 4.2.0

Discussed with maintainers on IRC.

Closes: https://bugs.gentoo.org/801490
Signed-off-by: Marek Szuba <marecki@gentoo.org>

dev-cpp/gtkmm/Manifest

@@ -1,2 +1,3 @@
 DIST gtkmm-2.24.5.tar.xz 12022024 BLAKE2B 6b2bca9fe6ad81cd956e1f3cc3140bc503b78386cf3931c8eeac08c8b2a08c73450bdbb703d1febaee67cdf834093ff5e89790f866357190822613a68a596ad3 SHA512 c50e52830977c37181439f4b82a30ac8bead0cf9022d2bec8225f8dc33e08414f863bf67056e1938fae8f888c09a5a6d757acc011fa9331a78caa6bb626dd51e
 DIST gtkmm-3.24.5.tar.xz 13540488 BLAKE2B b55c55e4bb56bc835be9c09dae59ee103fb0ae80ee99bb54c36c366686f4f1a0309435e91c2e323d7ebfabf7922b76ac85de6a1132c53ab708ba17be661d834b SHA512 8cc5aed26cc631123a5b38bc19643cf9e900beb38681b29ead9049f6b8f930f0b8ace317b8290279ab89cad85075dcb66863174082f77a2b67e4d8bd3c29de49
+DIST gtkmm-4.2.0.tar.xz 13850496 BLAKE2B 0e39824085fde11ebe3ecd65e3fbdb1778f307292a51b98955f4fa1418e7d1a349838126093b0a2b6d628b66d39bffffba76f66d2928999f777a4abb7961dc77 SHA512 c4532c427da0a37e4f8ba6f0e6d3975c3f84db461bc08263a4a81e6ee9e750112a2b4b0c5000ba22f8fd4fc5f833ef320f2c1f56580157f7ae41667ff15ccc72

dev-cpp/gtkmm/gtkmm-4.2.0.ebuild

@@ -0,0 +1,52 @@
+# Copyright 1999-2021 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{8..10} )
+inherit gnome.org meson python-any-r1 virtualx
+
+DESCRIPTION="C++ interface for GTK+"
+HOMEPAGE="https://www.gtkmm.org"
+
+LICENSE="LGPL-2.1+"
+SLOT="4.0"
+KEYWORDS="~amd64 ~arm ~arm64 ~ppc64 ~x86 ~amd64-linux ~x86-linux ~x86-solaris"
+IUSE="doc test"
+
+RESTRICT="!test? ( test )"
+
+RDEPEND="
+	>=dev-cpp/glibmm-2.68.0:2.68[doc?]
+	>=gui-libs/gtk-4.2.0:4
+	>=dev-cpp/cairomm-1.15.4:1.16[doc?]
+	>=dev-cpp/pangomm-2.48.0:2.48[doc?]
+	>=x11-libs/gdk-pixbuf-2.35.5:2
+	>=media-libs/libepoxy-1.2
+"
+DEPEND="
+	${RDEPEND}
+	doc? ( dev-libs/libsigc++:3 )
+"
+BDEPEND="
+	virtual/pkgconfig
+	doc? (
+		app-doc/doxygen[dot]
+		dev-lang/perl
+		dev-libs/libxslt
+	)
+	${PYTHON_DEPS}
+"
+
+src_configure() {
+	local emesonargs=(
+		-Dbuild-demos=false
+		$(meson_native_use_bool doc build-documentation)
+		$(meson_use test build-tests)
+	)
+	meson_src_configure
+}
+
+src_test() {
+	virtx meson_src_test
+}