CMakeLists.txt, with an example

CMakeLists.txt

@@ -1,13 +1,13 @@
+cmake_minimum_required(VERSION 3.5)
+project(robin-hood-hashing LANGUAGES CXX)
+
 # determine whether this is a standalone project or included by other projects
 set(RH_STANDALONE_PROJECT OFF)
 if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
     set(RH_STANDALONE_PROJECT ON)
 endif ()
 
 if (RH_STANDALONE_PROJECT)
-    cmake_minimum_required(VERSION 3.5)
-    project(robin-hood-hashing LANGUAGES CXX)
-
     option(RH_sanitizer "Address sanitizer" OFF)
     option(RH_coverage "Enable coverage" OFF)
     set(RH_cxx_standard "14" CACHE STRING "C++ standard, e.g. 11, 14, 17")

src/external_cmake/.gitignore

@@ -0,0 +1 @@
+build/

src/external_cmake/CMakeLists.txt

@@ -0,0 +1,15 @@
+# see https://cliutils.gitlab.io/modern-cmake/chapters/basics.html
+cmake_minimum_required(VERSION 3.1...3.15)
+
+if(${CMAKE_VERSION} VERSION_LESS 3.12)
+    cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
+endif()
+
+
+project(MyProject VERSION 1.0
+                  DESCRIPTION "Very nice project"
+                  LANGUAGES CXX)
+add_subdirectory("${PROJECT_SOURCE_DIR}/../.." "extern/robin_hood")
+
+add_executable(MyProject myproject.cpp)
+target_link_libraries(MyProject robin_hood)

src/external_cmake/myproject.cpp

@@ -0,0 +1,8 @@
+#include <iostream>
+#include <robin_hood.h>
+
+int main(int, char**) {
+    robin_hood::unordered_flat_map<int, int> map;
+    map[1] = 123;
+    std::cout << "hello, world! " << map.size() << std::endl;
+}