Motivation

I am using the following pattern to efficiently initialize a large buffer inside wasm memory from JavaScript without copies (see #1079 for full motivation):

#[wasm_bindgen]
pub struct WasmMemBuffer {
    buffer: Vec<u8>,
}

#[wasm_bindgen]
impl WasmMemBuffer {
    #[wasm_bindgen(constructor)]
    pub fn new(byte_length: u32, f: &js_sys::Function) -> Self {
  

For those of us who do wasm and things regularly we're going to miss out on what is unclear or not explained well. Help us by filing issues on things that are unclear in the book! It's an easy task to get involved with, opens up more things for us to fix, and helps us find out what still needs improvement!