From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- .../rustc_error_codes/src/error_codes/E0029.md | 26 ++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 compiler/rustc_error_codes/src/error_codes/E0029.md (limited to 'compiler/rustc_error_codes/src/error_codes/E0029.md') diff --git a/compiler/rustc_error_codes/src/error_codes/E0029.md b/compiler/rustc_error_codes/src/error_codes/E0029.md new file mode 100644 index 000000000..d12d85b9b --- /dev/null +++ b/compiler/rustc_error_codes/src/error_codes/E0029.md @@ -0,0 +1,26 @@ +Something other than numbers and characters has been used for a range. + +Erroneous code example: + +```compile_fail,E0029 +let string = "salutations !"; + +// The ordering relation for strings cannot be evaluated at compile time, +// so this doesn't work: +match string { + "hello" ..= "world" => {} + _ => {} +} + +// This is a more general version, using a guard: +match string { + s if s >= "hello" && s <= "world" => {} + _ => {} +} +``` + +In a match expression, only numbers and characters can be matched against a +range. This is because the compiler checks that the range is non-empty at +compile-time, and is unable to evaluate arbitrary comparison functions. If you +want to capture values of an orderable type between two end-points, you can use +a guard. -- cgit v1.2.3