Retrieve void* from TypedArray using Object::GetIndexedPropertiesExternalArrayData()

[Trevor Norris]

It was recently brought to my attention that the void* from an ArrayBuffer

created in JS can be retrieved from a TypedArray using

Object::GetIndexedPropertiesExternalArrayData(). Here's an example:

// JS side

var ui = new Uint8Array(new ArrayBuffer(16));

fillArray(ui);

// C++ side

void FillArray(const FunctionCallbackInfo<Value>& args) {

    Local<Object> o = args[0].As<Object>();

    char* data = static_cast<char*>(o->GetIndexedPropertiesExternalArrayData());

    // Now have a pointer to the data

}

Wanted to check if this was intentional or just a side-effect of some internal

implementation details. Also whether it is "safe" to use or not.