#include <memory>
#include <QApplication>
#include <QListWidget>
#include <QListWidgetItem>
#include <QPushButton>

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);

    auto item = new QListWidgetItem();
    auto button = new QPushButton("I'm a button.");
    button->setMinimumSize(50, 25);

    std::unique_ptr<QListWidget> list(new QListWidget());
    list->addItem(item);
    list->setItemWidget(item, button);
    list->show();

    return a.exec();
}