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Diffstat (limited to 'doc/manual/stmts.txt')
| -rw-r--r-- | doc/manual/stmts.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/doc/manual/stmts.txt b/doc/manual/stmts.txt index b24ec3b4a..721b5cff8 100644 --- a/doc/manual/stmts.txt +++ b/doc/manual/stmts.txt @@ -296,6 +296,10 @@ empty ``discard`` statement should be used. For non ordinal types it is not possible to list every possible value and so these always require an ``else`` part. +As case statements perform compile-time exhaustiveness checks, the value in +every ``of`` branch must be known at compile time. This fact is also exploited +to generate more performant code. + As a special semantic extension, an expression in an ``of`` branch of a case statement may evaluate to a set or array constructor; the set or array is then expanded into a list of its elements: |