Description
Refs #4914
When the style team was discussing the formatting rules for let-else, an unsurprisingly key consideration was if/when/how the entire statement could be formatted on one line. As noted in the now-codified rules, there is a "if short enough" element to the required conditions for one-line formatting in the spirit of being consistent with other prescriptions in the current style guide edition.
Specifically https://github.com/rust-lang/rust/blob/master/src/doc/style-guide/src/statements.md#single-line-let-else-statements
With an intentional clause added to note the anticipated need for configurability in rustfmt:
Formatters may allow users to configure the value of the threshold used to determine whether a let-else statement is short.
Therefore the only real question IMO is: do we reuse an existing option, e.g. single_line_if_else_max_width, or do we introduce a new option, e.g. single_line_let_else_max_width), and if the latter then what should the default value be?
My inclination is to do the latter (largely based on past experiences of multi-use config options being insufficiently flexible and causing problems), likely with the same default value as single_line_if_else_max_width though I feel less strongly about this.
What are your thoughts @ytmimi?
cc @rust-lang/style for awareness