When gdb prints a value, it first sees if there is a pretty-
printer registered for the value. If there is then gdb invokes
the pretty-printer to print the value. Otherwise the value is
printed normally. Pretty-printers are normally named. This makes
them easy to manage. The ‘info pretty-printer’ command will list
all the installed pretty-printers with their names. If a pretty-
printer can handle multiple data types, then its subprinters are
the printers for the individual data types. Each such subprinter
has its own name. The format of the name is printer-
name;subprinter-name. Pretty-printers are installed by
registering them with gdb. Typically they are automatically
loaded and registered when the corresponding debug information
is loaded, thus making them available without having to do
anything special. There are three places where a pretty-printer
can be registered. See Selecting Pretty-Printers, for further
information on how pretty-printers are selected, See Writing a
Pretty-Printer, for implementing pret