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nullptr pointer literal

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目次

[編集] 構文

nullptr (C + + 11以来)

[編集] 説明

キーワードnullptr、リテラルNULLポインタを表します。それは型の不特定prvaluestd::nullptr_tです。任意のポインタ型とメンバの型へのポインタのポインタの値をnullに<div class="t-tr-text">暗黙の型変換
Original:
implicit conversions
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からnullptr存在する。似たような変換は、タイプstd::nullptr_tの任意の値に対してだけでなく、マクロNULL、nullポインタ定数のために存在している.
Original:
The keyword nullptr denotes the null pointer literal. It is an unspecified prvalue of type std::nullptr_t. There exist
暗黙の型変換
Original:
implicit conversions
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</div> from nullptr to null pointer value of any pointer type and any pointer to member type. Similar conversions exist for any value of type std::nullptr_t as well as for the macro NULL, the null pointer constant.
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[編集] 例

nullptrを、テンプレート関数を介して転送することができる方法を示しています.
Original:
Demonstrates how nullptr allows forwarding via a template function.
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#include <cstddef>
#include <iostream>
 
template<class F, class A>
void Fwd(F f, A a)
{
    f(a);
}
 
void g(int* i)
{
    std::cout << "Function g called\n";
}
 
int main()
{
    g(NULL);           // Fine
    g(0);              // Fine
 
    Fwd(g, nullptr);   // Fine
//  Fwd(g, NULL);  // ERROR: No function g(int)
}

Output: 

Function g called
Function g called
Function g called

[編集] キーワード

nullptr

[編集] も参照してください
実装定義のヌルポインタ定数
Original:
implementation-defined null pointer constant
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(マクロ定数) [edit]
(C++11)
nullポインタリテラルnullptrのタイプ
Original:
the type of the null pointer literal nullptr
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(typedefです) [edit]
「http://ja.cppreference.com/mwiki/index.php?title=cpp/language/nullptr&oldid=20282」より作成