ref-struct

var ref = require('ref') var StructType = require('ref-struct') // define the time types var time_t = ref.types.long var suseconds_t = ref.types.long // define the "timeval" struct type var timeval = StructType({ tv_sec: time_t, tv_usec: suseconds_t }) // now we can create instances of it var tv = new timeval With node-ffi This gets very powerful when combined with node-ffi to invoke C functions: var ffi = require('ffi') var tv = new timeval gettimeofday(tv.ref(), null) Progressive API You can build up a Struct "type" incrementally (useful when interacting with a parser) using the defineProperty() function. But as soon as you create an instance of the struct type, then the struct type is finalized, and no more properties may be added to it. var ref = require('ref') var StructType = require('ref-struct') var MyStruct = StructType() MyStruct.defineProperty('width', ref.types.int) MyStruct.defineProperty('height', ref.types.int) var i = new MyStruct({ width: 5, height: 10 }) MyStruct.defineProperty('weight', ref.types.int) // AssertionError: an instance of this Struct type has already been created, cannot add new "fields" anymore // at Function.defineProperty (/Users/nrajlich/ref-struct/lib/struct.js:180:3)