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update immutable-checking situation #36

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Merged
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Feb 13, 2020
Merged

update immutable-checking situation #36

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Expand Up @@ -58,6 +58,11 @@ is actually accepted by the compiler because we know that there is no

*Dynamic check.* The Miri engine enforces this dynamically by ensuring that the
new data that is interned for a constant is all marked as immutable.
(Except for
[data inside promoteds](https://github.com/rust-lang/rust/blob/d538b80ad77949e46989cd355cdec193b574f052/src/librustc_mir/interpret/intern.rs#L363-L367)
which cannot easily be checked, and is thus just *marked* as immutable because
it descends from a shared reference subject to the strict syntactic checks of
lifetime extension.)

Note that a constant *referring to* some already existing mutable memory is
fine: inlining that reference everywhere has the same behavior as computing a
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