Summary This is a pre-RFC for a indentation field for the FormattingOptions struct in std::fmt that is used for giving directives to Formatter objects. A brief Github search for write!(f, "\t returns 7.6k results, which makes me believe the use case I had in mind, which is writing printers for recursive structures, is not that uncommon. While printing recursive structures, the typical mechanism is to pass a depth that can be used to decide what the indentation should be. If FormattingOptions....
