dev-cpp/cpp-taskflow: QA fixes and add live ebuild

- add a live ebuild as suggested in #733106

 - remove 3rd-party directory to make sure that bundled software is not
   used.

Closes: https://bugs.gentoo.org/733106
Package-Manager: Portage-3.0.28, Repoman-3.0.3
Signed-off-by: Matthias Maier <tamiko@gentoo.org>

dev-cpp/cpp-taskflow/cpp-taskflow-9999.ebuild

@@ -0,0 +1,43 @@
+# Copyright 1999-2021 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit cmake
+
+DESCRIPTION="Modern C++ Parallel Task Programming"
+HOMEPAGE="https://cpp-taskflow.github.io"
+if [[ ${PV} == 9999 ]]; then
+	EGIT_REPO_URI="https://github.com/cpp-taskflow/${PN}.git"
+	inherit git-r3
+	KEYWORDS=""
+	S="${WORKDIR}/cpp-taskflow-${PV}"
+else
+	SRC_URI="https://github.com/${PN}/${PN}/archive/v${PV}.tar.gz -> ${P}.tar.gz"
+	KEYWORDS="~amd64 ~x86"
+	S="${WORKDIR}/taskflow-${PV}"
+fi
+
+LICENSE="MIT"
+SLOT="0"
+IUSE="examples test"
+RESTRICT="!test? ( test )"
+
+HTML_DOCS=( docs/. )
+
+src_prepare() {
+	rm -r "${S}/3rd-party" || die "rm failed"
+	default
+	cmake_src_prepare
+}
+
+src_configure() {
+	# TODO: enable CUDA via USE flag
+	local mycmakeargs=(
+		-DTF_BUILD_CUDA=OFF
+		-DTF_BUILD_EXAMPLES=$(usex examples)
+		-DTF_BUILD_TESTS=$(usex test)
+	)
+
+	cmake_src_configure
+}