C++17 std::anyについて

nakameguro_feature.cpp vol.10
https://ebisu-effective-modern-cpp.connpass.com/event/104657/

での資料です!!

Transcript

1. $TUEBOZ
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   $Λ৮Γ࢝Ίͨͷ͸೥͘Β͍͔Β
   

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2. J04ͰήʔϜΛ࡞͍ͬͯ·͢
   ࠓ೔࿩͢͜ͱ
   $Ͱ௥Ճ͞Εͨ* ͷ࢖͍ํͱศརͳ࢖͍ํ
   ͳʹͿΜ$ॳ৺ऀͳͷͰποίϛ͓ئ͍͠·͢
   
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   ิ଍
   #include
   #include
   #include
   int main()
   {
   // sd p o
   auto a = std::make_any>({ 0, 1, 2, 3 });
   std::cout << std::any_cast>(a)[1]
   

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3. 
   ͷศརͳ࢖͍ํ
   * ʹ͍ͭͯ͸Θ͔͖ͬͯͨͷͰɺͲΜͳ࣌ʹ࢖͑Δͷ͔ͷ঺հ
   ίϯςφͱซͤͯ࢖͏
   << std::endl;
   }
   #include
   #include
   #include
   #include
   int main()
   {
   // std::vector
   auto a = std::vector{ -1, 8.5, "Hoge" };
   std::cout << std::any_cast(a[2])
   << std::endl;
   // std::map
   auto b = std::map{
   { "a", -1 },
   { "b", 8.5 },
   { "c", "Hoge" },
   };
   

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4. ԿͰ΋֨ೲͰ͖Δίϯςφܕ҆શੑͱ͸
   * ͸ ͕ແ͍ͷͰTUETFUʹ͸࢖͑ͣɻ
   +40/ͷಡΈॻ͖Ͱ࢖͑ͦ͏
   ਺஋ͱจࣈྻͷೖΓཚΕͨ஋ΛखؒΛ͔͚ͣʹѻ͑ͦ͏
   Πϕϯτॲཧ
   ήʔϜͰ͋Γ͕ͪͳ˓˓͖͔͚ͬͰॲཧΛ͢ΔΛߟ͑Δ
   std::cout << std::any_cast(b.at("b"))
   << std::endl;
   }
   #include
   #include
   int main()
   {
   std::set s;
   std::any a;
   s.insert(a);
   }
   LRESULT CALLBACK WndProc(HWND hwnd , UINT msg , WPARAM wp , LPARAM lp)
   

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5. 8JOEPXTͰΞϓϦΛ࡞Δͱ͖ͷϝοηʔδॲཧΛ͓खຊʹͯ͠ΈΔ
   {
   switch (msg)
   {
   case WM_DESTROY: // Window <
   PostQuitMessage(0);
   return 0;
   case WM_LBUTTONDOWN: //
   DoAnything(); //
   return 0;
   }
   return DefWindowProc(hwnd , msg , wp , lp);
   }
   #include
   #include
   #include
   //
   enum {
   GAME_START,
   GAME_END,
   PLAYER_DEAD,
   };
   //
   struct Item
   {
   // r t
   void event(int event_type)
   

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6. {
   switch (event_type)
   {
   case GAME_START:
   // r
   break;
   default:
   break;
   }
   }
   };
   // r
   void EventProc(int event_type)
   {
   switch (event_type)
   {
   case GAME_START:
   // r
   break;
   default:
   break;
   }
   }
   int main()
   {
   Item a;
   // t
   std::vector> func;
   

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7. ؔ਺΍ϝϯόؔ਺Λɺؔ਺ϙΠϯλͱͯ͠ొ࿥ͯ͠ஞ࣍ݺͼग़͢ͷ͸͙͢Ͱ͖Δ͕ɺ໰୊ͳͷ͕ίʔϧόοΫؔ਺ͷʮҾ
   ਺ʯͷܕɻ
   $ݴޠͰ࣮૷͍ͯͨ࣌͠͸ Ͱͨ͠
   ͦ͜ͰҾ਺Λ* ʹͯ͠ΈΔ
   //
   func.push_back(std::bind(&Item::event, &a, std::placeholders::_1));
   func.push_back(EventProc);
   // : v r
   for (auto& f : func)
   {
   f(GAME_START);
   }
   }
   #include
   #include
   #include
   enum {
   GAME_START,
   GAME_END,
   PLAYER_DEAD,
   };
   // GAME_START i t
   struct GameStartArg
   

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8. {
   int a;
   float b;
   };
   void EventProc(int event_type, std::any& arg)
   {
   switch (event_type)
   {
   case GAME_START:
   {
   // t o
   auto& a = std::any_cast(arg);
   }
   break;
   default:
   break;
   }
   }
   int main()
   {
   // t ay
   std::vector> func;
   //
   func.push_back(EventProc);
   // : t v r
   auto arg = std::make_any(GameStartArg{ -1, 0.5f });
   for (auto& f : func)
   {
   

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9. Ҿ਺༻ͷߏ଄ମΛ͍͍ͪͪఆٛ͢Δͷ͕ΊΜͲ͘͘͞ͳͬͨͷͰɺࠓ͸͜ͷํࣜ
   f(GAME_START, arg);
   }
   }
   #include
   #include
   #include
   #include
   #include
   enum {
   GAME_START,
   GAME_END,
   PLAYER_DEAD,
   };
   // t
   using Arguments = std::map;
   void EventProc(int event_type, Arguments& arg)
   {
   switch (event_type)
   {
   case GAME_START:
   {
   // t o
   auto a = std::any_cast(arg.at("a"));
   }
   

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10. ΊͬͪΌศརɻܕ҆શੑͱ͸ɻ
    6*ͷ֤छ෦඼Λѻ͏࣌
    break;
    default:
    break;
    }
    }
    int main()
    {
    // t ay
    std::vector> func;
    //
    func.push_back(EventProc);
    // : t v r
    auto arg = Arguments{
    { "a", -1 }, // int
    { "b", 0.5 }, // double
    };
    for (auto& f : func)
    {
    f(GAME_START, arg);
    }
    }
    

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11. ͋Γ͕ͪͳ6*ॲཧΛॻ͘ͱ͠·͢
    #include
    #include
    // UI
    struct UIBase
    {
    virtual void draw() = 0;
    virtual ~UIBase() {}
    };
    //
    struct UIBox : public UIBase
    {
    void draw()
    {
    // r
    }
    };
    struct UICircle : public UIBase
    {
    void draw()
    {
    // r
    }
    };
    int main()
    {
    // UI ay
    

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12. ͜ͷ࣍ͷεςοϓͰׂͱࠔΔ
    6*#PYͰͷαΠζࢦఆ
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    std::vector> ui;
    ui.push_back(std::make_shared());
    ui.push_back(std::make_shared());
    // e n
    for (auto& obj : ui)
    {
    obj->draw();
    }
    }
    #include
    #include
    #include
    #include
    #include
    // UI
    using Params = std::map;
    

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13. // UI
    struct UIBase
    {
    virtual void setParams(Params& params) = 0;
    virtual void draw() = 0;
    virtual ~UIBase() {}
    };
    //
    struct UIBox : public UIBase
    {
    void setParams(Params& params)
    {
    int w = std::any_cast(params.at("width"));
    int h = std::any_cast(params.at("height"));
    }
    void draw()
    {
    // r
    }
    };
    struct UICircle : public UIBase
    {
    void setParams(Params& params)
    {
    int r = std::any_cast(params.at("radius"));
    }
    void draw()
    {
    // r
    }
    

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14. 6*ΛςΩετ͔Βߏங͢Δ࣌ʹΊͬͪΌศརɻܕ҆શੑͱ͸ɻ
    ࢀߟࢿྉ
    };
    int main()
    {
    // UI ay
    std::vector> ui;
    ui.push_back(std::make_shared());
    ui.push_back(std::make_shared());
    auto params_box = Params{
    { "width", 100 },
    { "height", 150 },
    };
    ui[0]->setParams(params_box);
    auto params_circle = Params{
    { "radius", 50 },
    };
    ui[1]->setParams(params_circle);
    // e n
    for (auto& obj : ui)
    {
    obj->draw();
    }
    }
    

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15. IUUQTKBDQQSFGFSFODFDPNXDQQVUJMJUZBOZ
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