转换QList <std::string> 到QList <QString>

Question

Is there an easy way to create a QList<QString> from QList<std::string> ?

(Without iterating QList<std::string> and adding each element to QList<QString> )

Answer 1

The answer is NO. How could you possibly convert one into another without iterating? Even if you are using some kind of functions, that will be iterating through the list.

Answer 2

You can't do that without iterating through your list. You can still do it efficiently, avoiding unnecessary copies and reallocations:

QList<std::string> listStd;
listStd << "one" << "two" << "three";

QList<QString> listQt;
listQt.reserve(listStd.length());
for(const std::string& s : listStd)
{
    listQt.append(QString::fromStdString(s));
}

// listQt: "one", "two", "three"

If you don't want to convert, you may want to save your std::string directly as QString , thus avoiding the need to convert later.

QList<QString> lst; // or you can use the typedef QStringList 
....
std::string s = getting_a_std_string_from_this_function();
lst.append(QString::fromStdString(s));