ixion0.18: bump version

dev-libs/ixion/ixion0.18-0.19.0.recipe

@@ -10,9 +10,9 @@ and a partial calculation of only the affected cells need to be calculated."
 HOMEPAGE="https://gitlab.com/ixion/ixion"
 COPYRIGHT="Kohei Yoshida et al."
 LICENSE="MPL v2.0"
-REVISION="2"
+REVISION="1"
 SOURCE_URI="https://gitlab.com/ixion/ixion/-/archive/$portVersion/ixion-$portVersion.tar.bz2"
-CHECKSUM_SHA256="c2975b0aa9f6e1a76c690928cdaa6f48d414cf6f8cca83c9e8c713dec4da18f0"
+CHECKSUM_SHA256="c8b6315bae2d33a0e18b60004d625e4a5ea8a7326364f9f0b51cd6b49bdf93e8"
 SOURCE_DIR="ixion-$portVersion"
 
 ARCHITECTURES="all !x86_gcc2"
@@ -27,7 +27,7 @@ if [ "$targetArchitecture" = x86_gcc2 ]; then
 	commandBinDir=$prefix/bin
 fi
 
-soVersion="${portVersion%.*}"
+soVersion="0.18"
 
 PROVIDES="
 	ixion0.18$secondaryArchSuffix = $portVersion
@@ -100,6 +100,7 @@ PATCH()
 BUILD()
 {
 	autoreconf -fi
+	export CXXFLAGS="-std=c++17"
 	BOOST_ROOT="$portPackageLinksDir"/devel~libboost_program_options/develop
 	runConfigure --omit-dirs binDir ./configure \
 		--bindir=$commandBinDir \