CMake install and find_package working

CMakeLists.txt

 cmake_minimum_required(VERSION 3.16)
 project(bimap CXX)
-
+set(PROJECT_VERSION 0.0.1)
+#TODO: does this project require C++ 20? Then that should be part of the compile features of the targets
 set(CMAKE_CXX_STANDARD 20)
 
+include(GNUInstallDirs)
+
+# Define target
 add_library(bimap INTERFACE)
-target_include_directories(bimap INTERFACE include)
+add_library(ojl::bimap ALIAS bimap)
+target_include_directories(bimap
+    INTERFACE
+    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
+)
+target_sources(bimap
+    INTERFACE FILE_SET HEADERS
+    BASE_DIRS ${PROJECT_SOURCE_DIR}/include/ojl
+    FILES ${PROJECT_SOURCE_DIR}/include/ojl/bimap.hpp
+)
+
+#target_include_directories(bimap INTERFACE include)
+
+#REMEMBER, usually we would do target_include_directories(bimap PUBLIC $<BUILD_INTERFACE:${bimap_SOURCE_DIR}/include> $<BUILD_INTERFACE:${bimap_BINARY_DIR}/include> $<INSTALL_INTERFACE:include>)
+#But we just need the one in this case, since include is in the cmake root dir
 
 add_subdirectory(samples)
 
@@ -19,3 +38,34 @@ if (BUILD_TESTS)
     enable_testing()
     add_subdirectory(test)
 endif()
+
+# Define export set bimapTargets, install headers (but this doesn't actually install them...)
+install(TARGETS bimap
+    EXPORT bimapTargets
+    FILE_SET HEADERS DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/ojl
+)
+# Install the headers at the install location
+
+# Export the targets (?) what I don't get is how the bimapTargets.cmake differs from bimapConfig.cmake, why do we need both?
+# This still only installs a target named "bimap", not ojl::bimap ??? Even though it says NAMESPACE ojl here
+install(EXPORT bimapTargets
+    FILE bimapTargets.cmake
+    NAMESPACE ojl::
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/bimap
+)
+
+#TODO: generate a file that checks the version number using CMakePackageConfigHelpers (write_basic_package_version_file)
+include(CMakePackageConfigHelpers)
+write_basic_package_version_file(
+    "bimapConfigVersion.cmake"
+    VERSION ${bimap_VERSION}
+    COMPATIBILITY SameMajorVersion
+)
+
+install(FILES "bimapConfig.cmake" "${CMAKE_BINARY_DIR}/bimapConfigVersion.cmake"
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/bimap
+)
+
+### SEPARATE FILE TO BE INSTALLED ? ###
+# find dependencies if needed
+# include("${CMAKE_CURRENT_LIST_DIR}/bimapTargets.cmake}")

bimapConfig.cmake

+#This file could just be generated...
+include("${CMAKE_CURRENT_LIST_DIR}/bimapTargets.cmake")

cmake/fetch_catch2.cmake

@@ -2,7 +2,7 @@ include(FetchContent)
 
 find_package(Catch2 QUIET)
 if (NOT Catch2_FOUND)
-    message("Could not find Catch2 locally, downloading")
+    message(STATUS "Could not find Catch2 locally, downloading")
     set(FETCHCONTENT_QUIET FALSE)
     FetchContent_Declare(
         Catch2

samples/int_double_bimap.cpp

 #include <cstdio>
 #include <set>
 #include <utility>
-#include "bimap.hpp"
+#include "ojl/bimap.hpp"
 
 int
 main(int argc, char* argv[])

samples/int_int_bimap.cpp

 #include <cstdio>
 #include <set>
 #include <utility>
-#include "bimap.hpp"
+#include "ojl/bimap.hpp"
 
 bimap<int, int>
 test_bimap1()

test/bimap_api/bimap_test.cpp

-#include "bimap.hpp"
+#include "ojl/bimap.hpp"
 #include <string>
 #include <cstdint>
 #include <vector>

test/cmake/TestSetup.cmake

@@ -6,7 +6,7 @@ macro(find_catch2_and_define_test_target)
     find_package(Catch2 REQUIRED)
 
     if(Catch2_FOUND)
-        message("  found Catch2, version: ${Catch2_VERSION}")
+        message(STATUS "Test setup: found Catch2, version: ${Catch2_VERSION}")
         if(NOT TARGET Catch2::Catch2WithMain)
             message(SEND_ERROR
                 "Tests depend on Catch2::Catch2WithMain, but Catch2 was built without "