September 2015
Intermediate to advanced
364 pages
10h 33m
Japanese
Content preview from Effective Modern C++ ―C++11/14プログラムを進化させる42項目
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項目 19：共有するリソースの管理には std::shared_ptr を用いる
｜
123
shared_ptr については後続の項目 19 を参照）。
重要ポイント
•
std::unique_ptr は、独占所有するリソース管理用の、サイズが小さく、高速な、ムーブ専
用のスマートポインタである。
•
ディフォルトでは、リソースは delete により破棄されるが、カスタムデリータも指定可能
である。状態を持つデリータや、関数ポインタのデリータは std::unique_ptr オブジェク
トのサイズを増加させる。
•
std::unique_ptr の std::shared_ptr への変換は容易である。
項目 19：共有するリソースの管理には std::shared_ptr を用いる
ガーベジコレクション機能を備えた言語を使用するプログラマは、C++ プログラマがリソース解
放もれを防ぐ作業をするのを指差して笑い、「なんと原始的なことを！」と野次ります。「1960 年代
の Lisp から何も学んでいないのかい？ リソースのライフタイムを管理するのは人間じゃなくてマ
シンだよ。」と。C++ プログラマは目を剥いて言い返します。「その学んだことって言うのは、リソー
スと言えばメモリしか存在しなくて、非決定的なタイミングでリソースを回収する環境でのことか
い？ 俺達はデストラクタの汎用性と決定性を重視しているのさ。あばよ。」しかし、この我々の反論
には的外れな部分があります。ガーベジコレクションが有用なことは間違いありませんし ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.