#

# Input variables:

# - `EIGEN_DIR`

# If input variables are not specified, try to find Eigen3 config.

# Input variables could also be provided as environment variables.

#

# Output targets:

# - `Eigen3::Eigen`

UNIFY_ENVVARS_AND_CACHE(EIGEN_DIR)

if(EXISTS "${EIGEN_DIR}")

# Mimic Eigen3Config.cmake target.

add_library(Eigen3::Eigen INTERFACE IMPORTED)

target_include_directories(Eigen3::Eigen INTERFACE "${EIGEN_DIR}")

else()

find_package(Eigen3 CONFIG)

if(Eigen3_DIR)

message(STATUS "Eigen3: found config at '${Eigen3_DIR}'.")

else()

message(

FATAL_ERROR

"EIGEN_DIR is not provided or provided folder doesn't exist (current value: '${EIGEN_DIR}'). "

"Also couldn't find Eigen3 as a package."

)

endif()

endif()