--- /dev/null
+From 5ecd46bab07561758e0c37a9178e74175e989bdf Mon Sep 17 00:00:00 2001
+From: Alon Bar-Lev <alon.barlev@gmail.com>
+Date: Sat, 30 Mar 2019 09:59:46 +0300
+Subject: [PATCH] ICU-20530 Guard memory include for C++
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Introduce by ICU-20357, commit b7a3571b adding <memory> include without guard.
+
+Fails when compiling within extern "C".
+
+a.cxx
+---
+extern "C" {
+ #include <unicode/localpointer.h>
+}
+---
+In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/8.2.0/include/g++-v8/memory:84,
+ from /tmp/icu/icu4c/source/common/unicode/localpointer.h:45,
+ from a.cxx:4:
+/usr/lib/gcc/x86_64-pc-linux-gnu/8.2.0/include/g++-v8/backward/auto_ptr.h:325:3: error: template with C linkage
+ template<typename _Tp, typename _Dp>
+ ^~~~~~~~
+a.cxx:3:1: note: ‘extern "C"’ linkage started here
+ extern "C" {
+ ^~~~~~~~~~
+---
+
+Found by usage of xmlsec.
+
+Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com>
+---
+ icu4c/source/common/unicode/localpointer.h | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/icu4c/source/common/unicode/localpointer.h b/icu4c/source/common/unicode/localpointer.h
+index e011688b1a5..8e35ded0b10 100644
+--- a/common/unicode/localpointer.h
++++ b/common/unicode/localpointer.h
+@@ -42,7 +42,11 @@
+
+ #if U_SHOW_CPLUSPLUS_API
+
++#ifdef __cplusplus
++extern "C++" {
+ #include <memory>
++}
++#endif
+
+ U_NAMESPACE_BEGIN
+
--- /dev/null
+# Copyright 1999-2019 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+inherit flag-o-matic toolchain-funcs autotools multilib-minimal
+
+DESCRIPTION="International Components for Unicode"
+HOMEPAGE="http://www.icu-project.org/"
+SRC_URI="http://download.icu-project.org/files/icu4c/${PV/_/}/icu4c-${PV//./_}-src.tgz"
+
+LICENSE="BSD"
+
+SLOT="0/${PV}"
+
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86 ~ppc-aix ~amd64-fbsd ~x86-fbsd ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~x86-macos ~sparc-solaris ~sparc64-solaris ~x64-solaris ~x86-solaris ~x86-winnt"
+IUSE="debug doc examples static-libs"
+
+DEPEND="
+ doc? ( app-doc/doxygen[dot] )
+"
+BDEPEND="
+ virtual/pkgconfig
+"
+
+S="${WORKDIR}/${PN}/source"
+
+MULTILIB_CHOST_TOOLS=(
+ /usr/bin/icu-config
+)
+
+PATCHES=(
+ "${FILESDIR}/${PN}-58.1-remove-bashisms.patch"
+ "${FILESDIR}/${PN}-58.2-darwin.patch"
+ "${FILESDIR}/${P}-guard-memory-include.patch"
+)
+
+src_prepare() {
+ default
+
+ local variable
+
+ # Disable renaming as it is stupid thing to do
+ sed -i \
+ -e "s/#define U_DISABLE_RENAMING 0/#define U_DISABLE_RENAMING 1/" \
+ common/unicode/uconfig.h || die
+
+ # Fix linking of icudata
+ sed -i \
+ -e "s:LDFLAGSICUDT=-nodefaultlibs -nostdlib:LDFLAGSICUDT=:" \
+ config/mh-linux || die
+
+ # Append doxygen configuration to configure
+ sed -i \
+ -e 's:icudefs.mk:icudefs.mk Doxyfile:' \
+ configure.ac || die
+
+ eautoreconf
+}
+
+src_configure() {
+ append-cxxflags -std=c++14
+
+ if tc-is-cross-compiler; then
+ mkdir "${WORKDIR}"/host || die
+ pushd "${WORKDIR}"/host >/dev/null || die
+
+ CFLAGS="" CXXFLAGS="" ASFLAGS="" LDFLAGS="" \
+ CC="$(tc-getBUILD_CC)" CXX="$(tc-getBUILD_CXX)" AR="$(tc-getBUILD_AR)" \
+ RANLIB="$(tc-getBUILD_RANLIB)" LD="$(tc-getBUILD_LD)" \
+ "${S}"/configure --disable-renaming --disable-debug \
+ --disable-samples --enable-static || die
+ emake
+
+ popd >/dev/null || die
+ fi
+
+ multilib-minimal_src_configure
+}
+
+multilib_src_configure() {
+ local myeconfargs=(
+ --disable-renaming
+ --disable-samples
+ --disable-layoutex
+ $(use_enable debug)
+ $(use_enable static-libs static)
+ $(multilib_native_use_enable examples samples)
+ )
+
+ tc-is-cross-compiler && myeconfargs+=(
+ --with-cross-build="${WORKDIR}"/host
+ )
+
+ # icu tries to use clang by default
+ tc-export CC CXX
+
+ # make sure we configure with the same shell as we run icu-config
+ # with, or ECHO_N, ECHO_T and ECHO_C will be wrongly defined
+ export CONFIG_SHELL="${EPREFIX}/bin/sh"
+ # probably have no /bin/sh in prefix-chain
+ [[ -x ${CONFIG_SHELL} ]] || CONFIG_SHELL="${BASH}"
+
+ ECONF_SOURCE="${S}" econf "${myeconfargs[@]}"
+}
+
+multilib_src_compile() {
+ default
+
+ if multilib_is_native_abi && use doc; then
+ doxygen -u Doxyfile || die
+ doxygen Doxyfile || die
+ fi
+}
+
+multilib_src_test() {
+ # INTLTEST_OPTS: intltest options
+ # -e: Exhaustive testing
+ # -l: Reporting of memory leaks
+ # -v: Increased verbosity
+ # IOTEST_OPTS: iotest options
+ # -e: Exhaustive testing
+ # -v: Increased verbosity
+ # CINTLTST_OPTS: cintltst options
+ # -e: Exhaustive testing
+ # -v: Increased verbosity
+ emake -j1 VERBOSE="1" check
+}
+
+multilib_src_install() {
+ default
+
+ if multilib_is_native_abi && use doc; then
+ docinto html
+ dodoc -r doc/html/*
+ fi
+}
+
+multilib_src_install_all() {
+ einstalldocs
+ docinto html
+ dodoc ../readme.html
+}