名前空間
変種
操作

this pointer

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C + +言語
一般的なトピック
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General topics
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フロー制御
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Flow control
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条件付き実行文
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Conditional execution statements
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繰り返し文
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Iteration statements
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文をジャンプします
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Jump statements
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機能します
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Functions
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関数の宣言
ラムダ関数の宣言
関数テンプレート
の歴史。インライン指定
例外仕様 (廃止予定)
noexcept指定子 (C++11)
例外
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Exceptions
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名前空間
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Namespaces
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タイプ
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Types
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decltype specifier (C++11)
指定子
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Specifiers
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CV指定
貯蔵期間指定
constexprの指定子 (C++11)
自動指定 (C++11)
alignas指定子 (C++11)
初期化
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Initialization
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リテラル
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Literals
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Expressions
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代替表現
ユーティリティ
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Utilities
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タイプ
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Types
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typedef declaration
型の別名宣言 (C++11)
属性 (C++11)
キャストします
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Casts
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暗黙の型変換
const_cast conversion
static_cast conversion
dynamic_cast conversion
reinterpret_cast conversion
Cスタイルキャストと機能
メモリの割り当て
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Memory allocation
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クラス
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Classes
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クラス固有の機能特性
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Class-specific function properties
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明示 (C++11)
静的
特殊なメンバ関数
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Special member functions
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テンプレート
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Templates
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クラステンプレート
関数テンプレート
テンプレートの特殊化
パラメーターパック (C++11)
その他
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Miscellaneous
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インラインアセンブリ
 
非静的メンバ関数の内部では、関数が呼び出されたクラスオブジェクトへのポインタを保持している.
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Inside non-static member function, holds a pointer to the class object from which the function was invoked.
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thisはクラス名であり、cv T* constポインタが例えばインチは使用されている関数のTを指すcvポインタの型はCV指定とおりです
Original:
The type of this pointer is cv T* const where T is the class name and cv refers to the CV指定 of the function the pointer is used in. For example:
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Function signature Type of this
void T::foo()                T* const this;
void T::foo() const          const T* const this;
void T::foo() volatile       volatile T* const this;
void T::foo() const volatile const volatile T* const this;

[編集]

class T
{
    int x;
 
    void foo()
    {
        this->x = 5; // this used explicitly
        x = 6; // same as this->x = 6;
    }
 
    void foo() const
    {
        this->x = 7; // Error: *this is constant
    }
 
    void foo ( int x )
    {
        // parameter x shadows the attribute with the same name
        this->x = x; // unqualified x refers to the parameter, but the attribute is still accessible using the this pointer 
    }
 
    T& operator= ( const T& b )
    {
        x = b.x;
        return *this; // this is often used when a reference to the current object is needed
    }
 
    void bar ( const T& b )
    {
        // two ways to call class operators using this 
        (*this) = b;
        this->operator= ( b );
    }
 
    void bar()
    {
       // methods can be called even when there's no object
       // the this pointer can be seen like an additional parameter implicitly passed
       if ( this == NULL )
          return;
    }
};
 
T* pointer = reinterpret_cast<T*>(123);
pointer->bar(); // bar is called with 123 (0x7B) as value for this