dev-cpp/cld3: fix build with abseil-cpp-20260107

Don't inject `CMAKE_CXX_STANDARD` into the `CMakeLists.txt`. It should
have included `CACHE STRING ""` anyway to allow override.
Instead pass `CMAKE_CXX_STANDARD` as commandline argument.

Closes: https://bugs.gentoo.org/976176
Signed-off-by: Paul Zander <negril.nx+gentoo@gmail.com>
Part-of: https://github.com/gentoo/gentoo/pull/46315
Signed-off-by: Sam James <sam@gentoo.org>

dev-cpp/cld3/cld3-3.0.13_p20220331.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2025 Gentoo Authors
+# Copyright 1999-2026 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=8
@@ -27,11 +27,6 @@ src_prepare() {
 	sed -e '/add_definitions(/d' \
 		-i CMakeLists.txt || die
 
-	# Specify the c++ standard through cmake's heurestics instead
-	cat >> CMakeLists.txt <<- 'EOF' || die
-	set(CMAKE_CXX_STANDARD 17)
-	EOF
-
 	# Link with the right libraries for the tests
 	cat >> CMakeLists.txt <<- 'EOF' || die
 	target_link_libraries(cld3
@@ -88,3 +83,17 @@ src_prepare() {
 
 	cmake_src_prepare
 }
+
+src_configure() {
+	local CXXSTD="17"
+	if has_version ">=dev-cpp/abseil-cpp-20260107.0"; then
+		# needs >=c++20
+		CXXSTD="20"
+	fi
+
+	local mycmakeargs=(
+		-DCMAKE_CXX_STANDARD="${CXXSTD}"
+	)
+
+	cmake_src_configure
+}