How to get tab completion when using curly braces in Bash

In a Ubuntu (16.04) terminal you can do Ctrl+{ and then { and it autocompletes the curly brackets with the files in the directory. It uses commas instead of spaces to separate the files. For example, a directory containing these files: file.cpp file.h file.i file.py file_wrap.cxx

... would auto complete to this: $ cp file{.{cpp,h,i,py},_wrap.cxx}