glib::ustring str("Hello, world!");
glib::ustring str("Hello, world!"); int length = str.length();
glib::ustring str("Hello, world!"); str.replace(7, 5, "there");This replaces the substring "world" with "there" in the ustring, resulting in the string "Hello, there!". The `glib::ustring` data type is part of the GLib library, which is a low-level utility library for C++. It provides a variety of functions for data types commonly used in C++, such as linked lists, hash tables, and character sets. It also provides platform-specific functions for handling networking, threading, and other system-level tasks.