Current status

We are planning to to change the syntax for inclusive ranges and patterns to ..=. The ... syntax in patterns is stable and will remain (silently) deprecated for the time being; rustfmt can rewrite ... to ..=. This comes after much discussion. See this comment for justification.

No more syntax discussion should be had in this thread. Any different proposals of exclusive range syntax should take place on the user's forum or internals forum, after you have read all existing comments and their rationale here. Notably, breaking backwards compatibility is a non-starter.

Steps to take

• Initial implementation
• Change to accept ..= as synonym for ... in patterns and to accept ..= in expressions Initial support for ..= syntax #44709
  • Initial mentoring instructions on writing the PR can be found here.
• Documentation
  • Book Document inclusive ranges as a new feature. book#1134
  • Reference Document inclusive ranges. reference#215
  • Rust-by-example Document inclusive ranges. rust-by-example#1015
• Make RangeInclusive just a two-field struct (amend 1192) rfcs#1980 proposed a tweak to RangeInclusive
• Stabilization Stabilize inclusive range (..=) #47813
  • Note: The fields of RangeInclusive have been left out from this round of stabilization. Please track Tracking issue for start, end and new methods of RangeInclusive #49022 on this feature.