json/test/cmake_fetch_content/project/CMakeLists.txt
ArthurSonzogni c331706644 Add CMake fetchcontent documentation and tests
Github issue:
https://github.com/nlohmann/json/issues/2073

nlohmann::json documents 2 way of depending on it using CMake
1) Copy-paste the project/source into your own project.
2) Install nlohman::json and then use find_package.

(1) pollutes your git repository, (2) requires everyone to install the
dependencies themselves.

Since 2018, CMake provide some kind of 'package manager' features using
[FetchContent](https://cmake.org/cmake/help/v3.17/module/FetchContent.html)
It gives the following:
~~~cmake
include(FetchContent)

FetchContent_Declare(json
  GIT_REPOSITORY https://github.com/nlohmann/json
  GIT_TAG v3.7.3)

FetchContent_GetProperties(json)
if(NOT json_POPULATED)
  FetchContent_Populate(json)
  add_subdirectory( ${json_SOURCE_DIR} ${json_BINARY_DIR} EXCLUDE_FROM_ALL)
endif()
~~~

Then declares the dependency in the target using it:
~~~cmake
target_link_library(my_project PRIVATE nlohmann_json::nlohmann_json
~~~

This patch updates the documentation and provides tests.
2020-04-29 18:28:06 +02:00

21 lines
588 B
CMake

cmake_minimum_required(VERSION 3.11)
project(DummyImport CXX)
include(FetchContent)
FetchContent_Declare(json
GIT_REPOSITORY ${CMAKE_CURRENT_SOURCE_DIR}/../../..
GIT_TAG HEAD)
FetchContent_GetProperties(json)
if(NOT json_POPULATED)
FetchContent_Populate(json)
add_subdirectory(${json_SOURCE_DIR} ${json_BINARY_DIR} EXCLUDE_FROM_ALL)
endif()
add_executable(with_namespace_target main.cpp)
target_link_libraries(with_namespace_target nlohmann_json::nlohmann_json)
add_executable(without_namespace_target main.cpp)
target_link_libraries(without_namespace_target nlohmann_json)