clean question parsin in json

meson.build

@@ -0,0 +1,24 @@
+project('nlohmann_json',
+    'cpp',
+    version : '3.12.0',
+    license : 'MIT',
+)
+
+nlohmann_json_dep = declare_dependency(
+    include_directories: include_directories('single_include')
+)
+
+nlohmann_json_multiple_headers = declare_dependency(
+    include_directories: include_directories('include')
+)
+
+if not meson.is_subproject()
+install_headers('single_include/nlohmann/json.hpp', subdir: 'nlohmann')
+install_headers('single_include/nlohmann/json_fwd.hpp', subdir: 'nlohmann')
+
+pkgc = import('pkgconfig')
+pkgc.generate(name: 'nlohmann_json',
+    version: meson.project_version(),
+    description: 'JSON for Modern C++'
+)
+endif