Qt QString to std::string Conversion: Simple Guide

You can use the toStdString() function to convert a QString to a std::string. Here's an example:

QString qstr = 'Hello, world!';
std::string str = qstr.toStdString();

Note: If the QString contains Unicode characters, toStdString() will convert it to a std::string using UTF-8 encoding. If you need to use a different encoding, use QString::toUtf8() or QTextCodec.