C++ 中文周刊 第90期

class Derived : Base
{
    void DoSomething()
    {
        auto p1 = std::make_unique<BaseAcceptor>(static_cast<Base*>(this));
        auto p2 = std::make_shared<BaseAcceptor>(static_cast<Base*>(this));

        std::vector<BaseAcceptor> v;
        v.emplace_back(static_cast<Base*>(this));
    }
};

QNetworkReply *reply = ...
connect(reply, &QNetworkReply::finished, this, [reply]()) {
    reply->deleteLater();
    //...
});

auto nam = new QNetworkAccessManager(this);
nam->setRedirectPolicy(QNetworkRequest::NoLessSafeRedirectPolicy);

auto nam = new QNetworkAccessManager(this);
nam->setStrictTransportSecurityEnabled(true);
nam->enableStrictTransportSecurityStore(true, QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + QLatin1String("/hsts/"));

QNetworkReply *reply = ...
connect(reply, &QNetworkReply::sslErrors, this, [reply](const QList<QSslError> &errors) {
    KSslErrorUiData errorData(reply, errors);
    if (KIO::SslUi::askIgnoreSslErrors(errorData)) {
        reply->ignoreSslErrors();
    }
});

auto nam = new QNetworkAccessManager(this);
auto diskCache = new QNetworkDiskCache(nam);
diskCache->setCacheDirectory(QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + QLatin1String("/http/"));
nam->setCache(diskCache);

Logger& getLogger() {
  // Even if two threads call getLogger() simultaneously,
  // local will be constructed only once.
  static Logger local("log.txt");
  return local;
}

struct FileManager {
  FileManager()
  {
    getLogger() << "Starting up file manager…";
    // …
  }

  ~FileManager()
  {
    getLogger() << "Shutting down file manager…";
    // …
  }
};

FileManager& getFileManager() {
  // Global fileManager, initialized on the first call
  // to getFileManager().
  static FileManager fileManager;
  return fileManager;
}

auto counter = [j=0]() mutable -> decltype(j) {
    return j++;
};

auto lm = [][[nodiscard]]()->int { return 42; };

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