gistfile1.cpp

static Persistent<Function> isNaN;

bool V8Util::isValueNaN(Handle<Value> value)
{
        HandleScope scope;

	if (isNaN.isEmpty()) {
                Local<Object> global = Context::GetCurrent()->Global();
                Local<Value> isNaNValue = global->Get(String::NewSymbol("isNaN"));
                isNaN = Persistent<Function>::New(isNaNValue.As<Function>());
	}

	Handle<Value> args[] = { value };
	return isNaN->Call(Handle<Object>(), 1, args)->BooleanValue();
}