Function macro_state::proc_init_state
source · [−]Expand description
An analogue for clear_state!
that should only be used within proc macros.
Returns the value for the specified key
, if it exists. If it does not exist, the key is
created and set to the specified default_value
, and then the default_value
is returned.
Example
use macro_state::*;
proc_write_state("my key", "A").unwrap();
assert_eq!(proc_init_state("my key", "B").unwrap(), "A");
assert_eq!(proc_init_state("other key", "B").unwrap(), "B");