JS::MutableHandle 编辑

This article covers features introduced in SpiderMonkey 17

Reference to a T that has been rooted elsewhere. The underlying storage can be changed. This is useful for outparams.

Syntax

bool
someFunction(JSContext *cx, JS::MutableHandle<T> outParam) {
...
}

Methods

Here, ptr represents the private member of JS::MutableHandle<T>, typed with T *.

Description

JS::MutableHandle<T> is a non-const reference to JS::Rooted<T>. It is used in the same way as JS::Handle<T> and includes a |set(const T &v)| method to allow updating the value of the referenced JS::Rooted<T>. A JS::MutableHandle<T> can be created from a JS::Rooted<T> by using |JS::Rooted<T>::operator&()|.

If you want to add additional methods to JS::MutableHandle for a specific specialization, define a js::MutableHandleBase<T> specialization containing them.

There are typedefs available for the main types:

namespace JS {
typedef MutableHandle<JSFunction*> MutableHandleFunction;
typedef MutableHandle<jsid>        MutableHandleId;
typedef MutableHandle<JSObject*>   MutableHandleObject;
typedef MutableHandle<JSScript*>   MutableHandleScript;
typedef MutableHandle<JSString*>   MutableHandleString;
typedef MutableHandle<JS::Symbol*> MutableHandleSymbol;
typedef MutableHandle<Value>       MutableHandleValue;
}

See Also

• MXR ID Search for JS::MutableHandle
• MXR ID Search for JS::MutableHandleFunction
• MXR ID Search for JS::MutableHandleId
• MXR ID Search for JS::MutableHandleObject
• MXR ID Search for JS::MutableHandleScript
• MXR ID Search for JS::MutableHandleString
• MXR ID Search for JS::MutableHandleSymbol
• MXR ID Search for JS::MutableHandleValue
• JS::Rooted
• JS::Handle
• GC Rooting Guide
• bug 770759
• bug 761391 - added JS::MutableHandleScript
• bug 645416 - added JS::MutableHandleSymbol