The breaktarget
module defines one type: The BreakTarget
type. A
value of this type may be obtained by invoking BreakTarget::deploy
.
BreakTarget::deploy
takes a lambda, which is passed a reference to a
BreakTarget
. This object defines a single method, break_with
, which
takes a value of type T
and returns control flow to the site of the
BreakTarget::deploy
call, producing the value as the result. If the lambda
exits normally, it must also produce a value of type T
, which is produced
as the result of the BreakTarget::deploy
call.
The nonlocal breaking is implemented using a panic to unwind the stack. Any open Mutexes which are closed by this unwinding will be poisoned, among with other unwinding specific effects.
use breaktarget::Breaktarget;
let result = BreakTarget::deploy(|target| {
// ... Some logic here
target.break_with(10i32);
// ... Some logic here
});
assert_eq!(result, 10i32);
use breaktarget::BreakTarget;
fn some_function(target: &BreakTarget<i32>, cond: bool) {
if cond {
target.break_with(10);
}
}
let result1 = BreakTarget::deploy(|target| {
some_function(target, false);
20
});
assert_eq!(result1, 20);
let result2 = BreakTarget::deploy(|target| {
some_function(target, true);
20
});
assert_eq!(result2, 10);