Cannot use std::sort on a QJsonArray

I have a QJsonArray that only contains strings. When I try to use std::sort on the array, I get a compiler error message stating it could not find a swap function with the signature swap(QJsonValueRef, QJsonValueRef).

Example:

QJsonArray array;
array.append(QString("v1"));
array.append(QString("v2"));
std::sort(array.begin(), array.end(), [](QJsonValue &v1, QJsonValue &v2){
    return v1.toString() < v2.toString();
});

Gcc Error Message:

no matching function for call to 'swap(QJsonValueRef, QJsonValueRef)'
       swap(*__a, *__b);

My work around was to write the following code in a global header file:

inline void swap(QJsonValueRef v1, QJsonValueRef v2)
{
    QJsonValue temp(v1);
    v1 = QJsonValue(v2);
    v2 = temp;
}

Ideally, this function should live below the definition of QJsonValueRef.