マクロでオブジェクト指向

C++
  • boost::typeofのC++標準における実装の中で使われている
  • 「オブジェクト」とは型名(のようなトークン)の後にデータメンバのインスタンス(のようなトークン)の続いたSequenceと定義する
    • 例: (YOUR_CLASS)(data1)(data2)
  • 「メンバ関数」は型名の後にアンダースコアと関数名を付けたもので、呼び出しの最初の引数はオブジェクト自身とする
    • 例: YOUR_CLASS_MEMFUNC( (YOUR_CLASS)(data1)(data2), ... )



[]#include[][] <iostream>[]

[]#include[][] <boost/preprocessor/cat.hpp>[]

[]#include[][] <boost/preprocessor/seq.hpp>[]
[]// See: typeof_internals.htm.zip[]

[]//   at http://boost-sandbox.sourceforge.net/vault/index.php[]
[]#define[] []CAT_3[]([]a[], []b[], []c[]) []BOOST_PP_CAT[]([]a[], []BOOST_PP_CAT[]([]b[],[]c[]))






[]#define[] []TYPENAME[]([]Obj[]) []BOOST_PP_SEQ_HEAD[]([]Obj[])
[]#define[] []VIRTUAL[]([]Fun[], []Obj[])\

  []CAT_3[]([]TYPENAME[]([]Obj[]), []_[], []Fun[])



[]// STUDENT's constructor (syntax sugar)[]

[]#define[] []STUDENT[]\

  ([]STUDENT[])
[]// STUDENT's override[]

[]#define[] []STUDENT_PRINT[]([]This[], []n[])\

  []std[]::[]cout[] << []n[] << []":SEITO"[] << []std[]::[]endl[];
[]// TEACHER's constructor (syntax sugar)[]

[]#define[] []TEACHER[]([]Kamoku[])\

  ([]TEACHER[])([]Kamoku[])
[]// TEACHER's override[]

[]#define[] []TEACHER_PRINT[]([]This[], []n[])\

  []std[]::[]cout[] << []n[] << []":TANTOU:"[] << []TEACHER_GET_KAMOKU[]([]This[]) << []std[]::[]endl[];
[]#define[] []TEACHER_GET_KAMOKU[]([]Param[])\

    []BOOST_PP_SEQ_ELEM[](1, []Param[])
[]// FOR_EACH helper function[]

[]#define[] []PRINT_SCHOOLROOM[]([]r[], []data[], []n[], []elem[])\

    []VIRTUAL[]([]PRINT[], []elem[])([]elem[], []n[])
[]// your application[]

[]#define[] []SAKURA_SCHOOL[]     ([]OBJ_TARO[])([]OBJ_SAKAMOTO[])([]OBJ_ENDOU[])

[]#define[] []OBJ_TARO[]          []STUDENT[]

[]#define[] []OBJ_SAKAMOTO[]      []TEACHER[]([]"KOKUGO"[])

[]#define[] []OBJ_ENDOU[]         []TEACHER[]([]"RIKA"[])
[]int[] []main[]()

{

  []BOOST_PP_SEQ_FOR_EACH_I[]([]PRINT_SCHOOLROOM[], ~, []SAKURA_SCHOOL[])

  []// expands to[]

  []// std::cout << 0 << ":SEITO" << std::endl; std::cout << 1 << ":TANTOU:" << "KOKUGO"  << std::endl; std::cout << 2 << ":TANTOU:" << "RIKA"  << std::endl;  []

  

  []std[]::[]cin[].[]get[]();

  []return[] 0;

}