src/RangeSet.zig                                                                              |  41 +++---
 src/Sema.zig                                                                                  | 243 +++++++++++++++++---------------
 test/cases/compile_errors/duplicate_boolean_switch_value.zig                                  |   4 +-
 test/cases/compile_errors/duplicate_error_in_switch.zig                                       |   2 +-
 test/cases/compile_errors/switch_expression-duplicate_enumeration_prong.zig                   |   3 +-
 test/cases/compile_errors/switch_expression-duplicate_enumeration_prong_when_else_present.zig |   3 +-
 test/cases/compile_errors/switch_expression-duplicate_error_prong.zig                         |   4 +-
 test/cases/compile_errors/switch_expression-duplicate_error_prong_when_else_present.zig       |   4 +-
 test/cases/compile_errors/switch_expression-duplicate_or_overlapping_integer_value.zig        |  16 ---
 test/cases/compile_errors/switch_expression-duplicate_type.zig                                |   2 +-
 test/cases/compile_errors/switch_expression-duplicate_type_struct_alias.zig                   |   3 +-
 test/cases/compile_errors/switch_with_overlapping_case_ranges.zig                             |  42 +++++-
 12 files changed, 200 insertions(+), 167 deletions(-)