pub type JSTraceOp = Option<unsafe extern "C" fn(_: *mut JSTracer, _: *mut JSObject)>;
Expand description
Function type for trace operation of the class called to enumerate all traceable things reachable from obj’s private data structure. For each such thing, a trace implementation must call JS::TraceEdge on the thing’s location.
JSTraceOp implementation can assume that no other threads mutates object state. It must not change state of the object or corresponding native structures. The only exception for this rule is the case when the embedding needs a tight integration with GC. In that case the embedding can check if the traversal is a part of the marking phase through calling JS_IsGCMarkingTracer and apply a special code like emptying caches or marking its native structures.
Aliased Type§
enum JSTraceOp {
None,
Some(unsafe extern "C" fn(_: *mut JSTracer, _: *mut JSObject)),
}
Variants§
None
No value.
Some(unsafe extern "C" fn(_: *mut JSTracer, _: *mut JSObject))
Some value of type T
.
Trait Implementations§
source§impl<T: CustomTrace> CustomTrace for Option<T>
impl<T: CustomTrace> CustomTrace for Option<T>
source§impl<T: FromJSValConvertible> FromJSValConvertible for Option<T>
impl<T: FromJSValConvertible> FromJSValConvertible for Option<T>
§type Config = <T as FromJSValConvertible>::Config
type Config = <T as FromJSValConvertible>::Config
Optional configurable behaviour switch; use () for no configuration.
source§unsafe fn from_jsval(
cx: *mut JSContext,
value: HandleValue<'_>,
option: T::Config
) -> Result<ConversionResult<Option<T>>, ()>
unsafe fn from_jsval( cx: *mut JSContext, value: HandleValue<'_>, option: T::Config ) -> Result<ConversionResult<Option<T>>, ()>
Convert
val
to type Self
.
Optional configuration of type T
can be passed as the option
argument.
If it returns Err(())
, a JSAPI exception is pending.
If it returns Ok(Failure(reason))
, there is no pending JSAPI exception.