JSVAL_TO_GCTHING 编辑

Obsolete since JSAPI 32
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

Cast a jsval to a raw pointer of type void *.

Syntax

JSVAL_TO_GCTHING(v)

Description

JSVAL_TO_GCTHING casts a jsval, v, to a raw pointer. The type of the result is void *.

v must be either JSVAL_NULL or a reference to a GC thing. Otherwise the resulting pointer is undefined. JSVAL_IS_GCTHING may be used to check this.

This macro is exposed in jsapi.h because other JSAPI macros make use of it. Applications should not call it directly in most cases. When possible, it is better to use a more specific macro, such as JSVAL_TO_OBJECT or JSVAL_TO_STRING. Another possible alternative is to avoid casting altogether by using an API that operates on jsvals rather than raw pointers (for example, JS_CALL_VALUE_TRACER rather than JS_CALL_TRACER).

See Also

• bug 952650