From 0b231f45fcb402e62bf0695a676f80019a815183 Mon Sep 17 00:00:00 2001
From: "Damien Buhl (alias daminetreg)" <damien.buhl@lecbna.org>
Date: Sun, 20 Sep 2015 19:12:27 +0200
Subject: [PATCH] support cmake package config file to make the library
 searchable with find_package.

---
 CMakeLists.txt                              | 48 +++++++++++++++------
 cmake/modules/nlohmann-json-config.cmake.in | 23 ++++++++++
 2 files changed, 59 insertions(+), 12 deletions(-)
 create mode 100644 cmake/modules/nlohmann-json-config.cmake.in

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a1fb47e8f..c4f3ec783 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,25 +1,49 @@
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 3.0.0)
 
 project(json CXX)
 
+set (json_VERSION "1.0.0-rc1")
+
 add_executable(json_unit
     src/json.hpp test/catch.hpp test/unit.cpp
 )
 
-if(MSVC)
-    set(CMAKE_CXX_FLAGS
-        "/EHsc"
-    )
+if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
+  set(CMAKE_CXX_FLAGS "-std=c++11 -stdlib=libc++")
 
-    STRING(REPLACE "/O2" "/Od" CMAKE_CXX_FLAGS_RELEASE ${CMAKE_CXX_FLAGS_RELEASE})
+elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+    set(CMAKE_CXX_FLAGS "-std=c++11")
 
-    add_definitions(-D_SCL_SECURE_NO_WARNINGS)
-else(MSVC)
-    set(CMAKE_CXX_FLAGS
-        "-std=c++11 -stdlib=libc++"
-    )
-endif(MSVC)
+elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+  set(CMAKE_CXX_FLAGS "/EHsc")
+
+  STRING(REPLACE "/O2" "/Od" CMAKE_CXX_FLAGS_RELEASE ${CMAKE_CXX_FLAGS_RELEASE})
+
+  add_definitions(-D_SCL_SECURE_NO_WARNINGS)
+endif()
 
 include_directories(
     src test
 )
+
+install(DIRECTORY ${CMAKE_CURRENT_LIST_DIR}/src/ DESTINATION include/nlohmann
+        FILES_MATCHING PATTERN "*.[ih]pp")
+
+include(CMakePackageConfigHelpers)
+set(INCLUDE_INSTALL_DIR include/)
+set(DEFINITIONS "${CMAKE_CXX_FLAGS}")
+configure_package_config_file(
+  ${CMAKE_CURRENT_LIST_DIR}/cmake/modules/nlohmann-json-config.cmake.in
+  ${CMAKE_CURRENT_BINARY_DIR}/nlohmann-json-config.cmake
+  INSTALL_DESTINATION lib/cmake/nlohmann-json-${json_VERSION}
+  PATH_VARS INCLUDE_INSTALL_DIR)
+
+write_basic_package_version_file(
+    ${CMAKE_CURRENT_BINARY_DIR}/nlohmann-json-config-version.cmake
+    VERSION ${json_VERSION}
+    COMPATIBILITY AnyNewerVersion)
+
+install(FILES
+    ${CMAKE_CURRENT_BINARY_DIR}/nlohmann-json-config.cmake
+    ${CMAKE_CURRENT_BINARY_DIR}/nlohmann-json-config-version.cmake
+    DESTINATION lib/cmake/nlohmann-json-${json_VERSION})
diff --git a/cmake/modules/nlohmann-json-config.cmake.in b/cmake/modules/nlohmann-json-config.cmake.in
new file mode 100644
index 000000000..073f6de11
--- /dev/null
+++ b/cmake/modules/nlohmann-json-config.cmake.in
@@ -0,0 +1,23 @@
+# It can be used as :
+#  
+# find_package(nlohmann-json)
+# target_link_libraries(program nlohmann-json::nlohmann-json)
+#
+# It also defines 
+#   - ${NLOHMANN_JSON_INCLUDE_DIRS}
+#   - ${NLOHMANN_JSON_DEFINITIONS}
+#
+set(NLOHMANN_JSON_VERSION @json_VERSION@)
+
+@PACKAGE_INIT@
+
+set_and_check(NLOHMANN_JSON_INCLUDE_DIRS "@PACKAGE_INCLUDE_INSTALL_DIR@")
+set(NLOHMANN_JSON_DEFINITIONS "@CMAKE_CXX_FLAGS@")
+check_required_components(nlohmann_json) 
+
+if (NOT TARGET "nlohmann-json::nlohmann-json")
+  add_library("nlohmann-json::nlohmann-json" INTERFACE IMPORTED)
+  set_target_properties("nlohmann-json::nlohmann-json"
+    PROPERTIES
+    INTERFACE_INCLUDE_DIRECTORIES "${NLOHMANN_JSON_INCLUDE_DIRS}")
+endif()