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EnvGuard

Struct EnvGuard 

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pub struct EnvGuard(/* private fields */);
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RAII guard that proves ownership of the process-wide environment lock.

Obtain one with lock; while it is alive, no other thread can enter the safe mutation methods on this type. Dropping the guard releases the lock.

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impl EnvGuard

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pub fn set_var(&self, key: impl AsRef<OsStr>, value: impl AsRef<OsStr>)

Set a process environment variable.

Safe because self proves the global env mutex is held, so no other caller routed through this module is reading or writing the environment concurrently.

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pub fn remove_var(&self, key: impl AsRef<OsStr>)

Remove a process environment variable.

See Self::set_var for the safety argument.

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pub fn restore_var<T: AsRef<OsStr>>(&self, key: &str, previous: Option<T>)

Restore a variable to its previous value, or remove it if there was none.

Pairs with std::env::var_os snapshots taken before a mutation.

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