From 7f0ca894e87ef8044a03e98ea262112cac060f9e Mon Sep 17 00:00:00 2001
From: wuyangfan <1102042793@qq.com>
Date: Sun, 17 May 2026 23:51:56 +0800
Subject: [PATCH] fix(meson): install CMake package config files

Install nlohmann_jsonConfig.cmake, nlohmann_jsonConfigVersion.cmake,
and nlohmann_jsonTargets.cmake when building with Meson so consumers
can use find_package(nlohmann_json) after a Meson install.

Fixes #3885
---
 cmake/nlohmann_jsonTargets.cmake | 13 +++++++++++++
 meson.build                      | 31 +++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 cmake/nlohmann_jsonTargets.cmake

diff --git a/cmake/nlohmann_jsonTargets.cmake b/cmake/nlohmann_jsonTargets.cmake
new file mode 100644
index 0000000000..1e6709d9a2
--- /dev/null
+++ b/cmake/nlohmann_jsonTargets.cmake
@@ -0,0 +1,13 @@
+# Installed by Meson for find_package(nlohmann_json) compatibility with the CMake build.
+
+if(NOT TARGET nlohmann_json::nlohmann_json)
+    get_filename_component(
+        _nlohmann_json_include_dir
+        "${CMAKE_CURRENT_LIST_DIR}/../../../include"
+        ABSOLUTE)
+    add_library(nlohmann_json::nlohmann_json INTERFACE IMPORTED)
+    set_target_properties(nlohmann_json::nlohmann_json PROPERTIES
+        INTERFACE_COMPILE_FEATURES "cxx_std_11"
+        INTERFACE_INCLUDE_DIRECTORIES "${_nlohmann_json_include_dir}"
+    )
+endif()
diff --git a/meson.build b/meson.build
index a2d6e31a25..a31daa8ea4 100644
--- a/meson.build
+++ b/meson.build
@@ -21,4 +21,35 @@ pkgc.generate(name: 'nlohmann_json',
     version: meson.project_version(),
     description: 'JSON for Modern C++'
 )
+
+cmake_dir = get_option('datadir') / 'cmake' / meson.project_name()
+version_parts = meson.project_version().split('.')
+
+cmake_conf = configuration_data()
+cmake_conf.set('PROJECT_NAME', meson.project_name())
+cmake_conf.set('NLOHMANN_JSON_TARGET_NAME', meson.project_name())
+cmake_conf.set('NLOHMANN_JSON_TARGETS_EXPORT_NAME', meson.project_name() + 'Targets')
+cmake_conf.set('PROJECT_VERSION', meson.project_version())
+cmake_conf.set('PROJECT_VERSION_MAJOR', version_parts[0])
+
+configure_file(
+    input: 'cmake/config.cmake.in',
+    output: meson.project_name() + 'Config.cmake',
+    configuration: cmake_conf,
+    install: true,
+    install_dir: cmake_dir,
+)
+
+configure_file(
+    input: 'cmake/nlohmann_jsonConfigVersion.cmake.in',
+    output: meson.project_name() + 'ConfigVersion.cmake',
+    configuration: cmake_conf,
+    install: true,
+    install_dir: cmake_dir,
+)
+
+install_data(
+    'cmake/nlohmann_jsonTargets.cmake',
+    install_dir: cmake_dir,
+)
 endif