| A lower range wasn't less than the upper range. | |
| Erroneous code example: | |
| ```compile_fail,E0579 | |
| fn main() { | |
| match 5u32 { | |
| // This range is ok, albeit pointless. | |
| 1..2 => {} | |
| // This range is empty, and the compiler can tell. | |
| 5..5 => {} // error! | |
| } | |
| } | |
| ``` | |
| When matching against an exclusive range, the compiler verifies that the range | |
| is non-empty. Exclusive range patterns include the start point but not the end | |
| point, so this is equivalent to requiring the start of the range to be less | |
| than the end of the range. |