# Vendored Eigen 3.4.0 headers

Eigen 3.4.0 (libeigen/eigen at commit
3147391d946bb4b6c68edd901f2add6ac1f31f8c - the exact release libCZI pins in
its cmake/ExternalEIGEN3.cmake) is vendored here, header-only, so that
libczirw-sys builds need neither network access during the build (libCZI's
default Eigen ExternalProject clone from gitlab.com is flaky in CI) nor a
system libeigen3-dev package.

Only the Eigen/ core-module tree is vendored - libCZI only does
#include <Eigen/Eigen>. COPYING.MPL2 and COPYING.README are the
upstream license files (Eigen defaults to MPL-2.0, with LGPL-3.0/GPL-3.0 as
alternatives).

Eigen3Config.cmake in this directory provides the Eigen3::Eigen interface
target for CMake consumers using find_package(Eigen3 ...) (see
LIBCZI_BUILD_PREFER_EXTERNALPACKAGE_EIGEN3 in the libCZI build).