How can I get all options from meson_options.txt

Is there any facility (cli, online, etc) where from one meson_options.txt file I can get all the options filled in with the defaults?

e.g.

$ meson_get_all_options
CMD -Doption=true -Doption2=42

1. Run meson setup to create default build configuration
2. Run meson introspect --buildoptions to dump all options in JSON format
3. Parse JSON output
4. Filter out records with section=user

Example code in Lua:

-- some JSON decoder required
local json = require"json"

local projdir = "/path/to/project"
local tempdir = "/tmp/build"

assert(os.execute(string.format("meson setup %s %s >/dev/null", tempdir, projdir)))

local handle = io.popen(string.format("meson introspect %s --buildoptions", tempdir))
local data = json.decode(handle:read("*all"))
handle:close()

for i, v in ipairs(data) do
    if v.section == "user" then
        io.write(string.format("-D%s=%s ", v.name, v.value))
    end
end

os.execute(string.format("rm -r %s", tempdir))