... https://github.com/wlav/cppyy
(.require
 [library
  [lux (.except)
   [program (.only program)]
   ["[0]" ffi (.only import)]
   ["[0]" debug]
   [abstract
    [monad (.only do)]]
   [control
    ["[0]" maybe (.use "[1]#[0]" monad)]
    ["[0]" try (.only Try)]
    ["[0]" exception (.only Exception)]
    ["[0]" io (.only IO io)]]
   [data
    ["[0]" product]
    [text
     ["%" \\format (.only format)]
     [encoding
      ["[0]" utf8]]]
    [collection
     ["[0]" array (.only Array)]]]
   [math
    [number
     ["n" nat]
     ["i" int]
     ["[0]" i64]]]
   ["[0]" world
    ["[0]" file]
    ["[1]/[0]" environment]]
   [meta
    [macro
     ["^" pattern]
     ["[0]" template]]
    [compiler
     [target
      ["_" c++ (.only)
       [":" type]]]
     [reference
      [variable (.only Register)]]
     [language
      [lux
       [program (.only Program)]
       [translation (.only Host)]
       [analysis
        [macro (.only Expander)]]
       ["[0]" phase (.only Operation Phase)
        ["[0]" extension (.only Extender Handler)
         ["[0]" analysis
          ["[1]" js]]
         ["[0]" translation
          ["[1]" js]]]
        [translation
         ["[0]" reference]
         [c++
          ["[0]" runtime]
          ["[0]" type]
          ["[0]" primitive]
          ["[0]" complex]]]]]]
     [default
      ["[0]" platform (.only Platform)]]
     [meta
      ["[0]" cli]
      ["[0]" context]
      [archive (.only Archive)
       ["[0]" unit]]
      ["[0]" packager
       ["[1]" script]]]]]]]
 [program
  ["/" compositor]])

(import cppyy
  "[1]::[0]"
  ("static" cppdef [Text] "io" Bit)
  ("static" gbl (ffi.Object Any)))

(def standard_out (_.global [_.standard "cout"] (list)))
(def \n (_.global [_.standard "endl"] (list)))

(def (print it)
  (-> _.Expression
      _.Statement)
  (|> standard_out
      (_.<< it)
      (_.<< \n)
      _.;))

(with_expansions [<say_hello> "say_hello"]
  (def _
    (program []
      (do io.monad
        [? (cppyy::cppdef [(_.code (all _.then
                                        runtime.declaration

                                        (_.include "iostream")
                                        (_.function (_.local <say_hello>)
                                          (list)
                                          (list)
                                          :.void
                                          (all _.then
                                               (print (_.deref (runtime.host_value type.bit (runtime.simple type.bit (primitive.bit true)))))
                                               (print (_.deref (runtime.host_value type.i64 (runtime.simple type.i64 (primitive.i64 +123)))))
                                               (print (_.deref (runtime.host_value type.f64 (runtime.simple type.f64 (primitive.f64 -456.789)))))
                                               ... (print (_.deref (runtime.host_value type.text (runtime.simple type.text (primitive.text "YOLO")))))
                                               ))))])
         .let [_ (debug.log! (%.format "BEFORE " (%.bit ?)))]
         global (cppyy::gbl)
         .let [say_hello (as ffi.Function
                             (.python_object_get# <say_hello> global))
               _ (debug.log! "AFTER")
               _ (.python_apply# say_hello [])]]
        (in (debug.log! "Hello, C++"))))))