javascript - Unwrapping objects members with V8/Node.JS -

i'm learning v8/node.js through 1 of project , i'm wondering if there way unwrap c++ object inherited node::ojectwrap (from node.js api) and members @ same time.

all examples can found have int members instance , of them try wrap c++ object members. here code explanation of want do:

// basic class contains vector member // note not interact v8 or node.js code class b {   public:   // constructors , methods...   size_t getsize(void) { return vec_.size(); };    private:     std::vector<int> vec_; }   // class instanciate correctly in javascript code class : public node::objectwrap {   public:     static void init(v8::handle<v8::value> exports);     static v8::handle<v8::value> new(const v8::arguments& args); // method use instanciate js object     static v8::handle<v8::value> update(const v8::arguments& args); // method call    private:     a(b b) : b_(b) {};     ~a(void);    private:     static v8::persistent<v8::function> constructor_;     b b_; } 

to keep things simple, here definitions of a::new , a::update. i'm using google v8 documentation sample code others methods.

v8::handle<v8::value> a::new(const v8::arguments& args) {   v8::handlescope scope;    if (args.isconstructorcall())   {     b b;     // fill vector of b n elements...     // if print here size of a->b_.size(), n      a* = new a(b);     a->wrap(args.this());      return args.this();   }   else     // ... }  v8::handle<v8::value> a::update(const v8::arguments& args) {   v8::handlescope scope;    a* = objectwrap::unwrap<a>(args.this());   // if print here size of a->b_.size(), garbage value } 

finally, javascript code:

var = new addon.a(/* constructor parameters *); // print size value a.update(); // print garbage value 

it seems b member of a not wrapped correctly. question is: possible wrap object members without inherited them of node::objectwrap ?

thanks help.

for may in same situation, found out error.

in fact, allocating b member on stack , since method call in a class statics, can have access garbage values between 2 calls (here a::new , a::update).

i solve problem allocating b object on heap.