コンパイルタイム・ポリモーフィズム

C++ Grammar
  • 前日分を少し実践的に書き直しました
  • VC6からComeauまで動きます
  • おそらくこれがC++のポリモーフィズムの答えであると思われる
    • Boost.Rangeはあのままではまずいと思う
  • Boost.Serializationではoverloadedの部分がconst unsigned int versionになっていて、version番号、VC6の不具合の回避、2nd phase ADL、の三つの役割を持っている！



[]#include[] []<boost/config.hpp>[] []// for BOOST_NO_FUNCTION_TEMPLATE_ORDERING[]

[]#include[] []<boost/pfto.hpp>[]

[]#include[] []<boost/strong_typedef.hpp>[]




[]namespace[] []poost[][] {[]

  

  []// See: <boost/serialization/serialization.hpp>[]
  []namespace[] []xxx_overload_set[][] {[]
    []typedef[] []int[] []overloaded[][]; [][]// nicely named for users[]

    []BOOST_STRONG_TYPEDEF[][]([][]overloaded[][], [][]adl_trigger_type[][]) [][]// ADL trigger[]
    []////////////////////////////////////////////////////////////////////////////////[]

    []//  library-defined []

    []//    BOOST_PFTO works only if overloads are in the same namespace.[]

    []//[]

    []template[][]< [][]class[] []T[][] > [][]// default[]

    []void[] []poost_xxx[][]([][]T[][]&, [][]BOOST_PFTO[] []overloaded[][])[]

[]    {[]

      []POOST_PRINT[][]([][]default[] []poost[][]::[][]xxx[][]);[]

[]    }[]
    []inline[] []void[] []poost_xxx[][]([][]char[][], [][]overloaded[][])[]

[]    {[]

      []POOST_PRINT[][]([][]poost[][]::[][]xxx[][]([][]char[][]));[]

[]    }[]
    []template[][]< [][]class[] []T[][] >[]

    []void[] []poost_xxx[][]([][]std[][]::[][]list[][]<[][]T[][]>&, [][]overloaded[][])[]

[]    {[]

      []POOST_PRINT[][]([][]poost[][]::[][]xxx[][]([][]std[][]::[][]list[][]<>&));[]

[]    }[]
[]  } [][]// namespace xxx_overload_set[]
  []template[][]< [][]class[] []T[][] >[]

  []void[] []xxx[][]([][]T[][]& [][]x[][])[]

[]  {[]

    []using[] []namespace[] []xxx_overload_set[][];[]

    

[]#if[][] !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)[]

    []adl_trigger_type[] []trigger[][]([][]0[][]);[]

    []poost_xxx[][]([][]x[][], [][]trigger[][]);[]

[]#else[]

    []overloaded[] []pfto[][]([][]0[][]);[]

    []poost_xxx[][]([][]x[][], [][]pfto[][]);[]

[]#endif[]

[]  }[]
[]} [][]// namespace poost[]
[]// An important function[]

[]template[][]< [][]class[] []T[][] >[]

[]void[] []yyy[][]([][]T[][]& [][]x[][])[]

[]{[]

  []poost[][]::[][]xxx[][]([][]x[][]);[]

  []// ...[]

[]}[]
[]// user-defined customization[]

[]namespace[] []poost[][] { [][]namespace[] []xxx_overload_set[][] {[]
  []inline[] []void[] []poost_xxx[][]([][]int[][], [][]overloaded[][])[]

[]  {[]

    []POOST_PRINT[][]([][]poost[][]::[][]xxx[][]([][]int[][]));[]

[]  }[]
  []template[][]< [][]class[] []T[][] >[]

  []void[] []poost_xxx[][]([][]std[][]::[][]vector[][]<[][]T[][]>&, [][]overloaded[][])[]

[]  {[]

    []POOST_PRINT[][]([][]poost[][]::[][]xxx[][]([][]std[][]::[][]vector[][]<>&));[]

[]  }[]
[]} } [][]// namespace poost::xxx_overload_set[]
[]void[] []test[][]()[]

[]{[]

  []int[] []i[][];[]

[]  ::[][]yyy[][]([][]i[][]);[]
  []std[][]::[][]vector[][]<[][]int[][]> [][]vec[][];[]

[]  ::[][]yyy[][]([][]vec[][]);[]
  []std[][]::[][]list[][]<[][]int[][]> [][]lst[][];[]

[]  ::[][]yyy[][]([][]lst[][]);[]
  []char[] []ch[][];[]

[]  ::[][]yyy[][]([][]ch[][]);[]
  []std[][]::[][]string[] []str[][];[]

[]  ::[][]yyy[][]([][]str[][]); [][]// default[]

[]}[]