feat(README, filledDataView, sizedDataView)

src/index.js

@@ -1,5 +1,5 @@
 import { limits } from './limits'
-import { memcpy } from './mem'
+import { sizedDataView, filledDataView, memcpy } from './mem'
 import { Type } from './Type'
 import { Int } from './Int'
 import { ConstString } from './ConstString'
@@ -10,6 +10,8 @@ import { Struct } from './Struct'
 
 export {
   limits,
+  sizedDataView,
+  filledDataView,
   memcpy,
   Type,
   Int,
@@ -217,7 +219,13 @@ export function sizeof(...args) {
   if (arg2 instanceof Type) {
     return arg2.sizeof(arg, ...inner_args2)
   }
-  throw new Error('unknown size of ' + args)
+  throw new Error(
+    'unknown size of ' +
+      args.map((arg) => {
+        if (typeof arg == 'function') return arg.name
+        return arg
+      }),
+  )
 }
 
 export function isSerializableType(type) {