From b795e3db9a976e869da07aaf7655ab0944b8d379 Mon Sep 17 00:00:00 2001
From: Henri Menke <henri@henrimenke.de>
Date: Thu, 21 Sep 2023 11:15:06 +0200
Subject: [PATCH] fix: require Eigen 3.4

STL iterators and C++20 compatibility was only added in Eigen 3.4
---
 c++/triqs_Nevanlinna/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/c++/triqs_Nevanlinna/CMakeLists.txt b/c++/triqs_Nevanlinna/CMakeLists.txt
index 5fc1c2e..a8ce905 100644
--- a/c++/triqs_Nevanlinna/CMakeLists.txt
+++ b/c++/triqs_Nevanlinna/CMakeLists.txt
@@ -31,7 +31,7 @@ install(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} DESTINATION include FILES_MATCHING
 
 # ========= Library Dependencies ==========
 
-find_package(Eigen3 REQUIRED)
+find_package (Eigen3 3.4 REQUIRED CONFIG)
 target_link_libraries(${PROJECT_NAME}_c PUBLIC Eigen3::Eigen)
 
 find_package(Boost REQUIRED)