fi-0062: Newtypes are not allowed {:#fi-0062}

Newtypes from RFC-0052: Type aliasing and new types are not fully implementented and cannot be used yet:

{% include “docs/reference/fidl/language/error-catalog/label/_bad.md” %}

{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/bad/fi-0062.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}

In the meantime, you can achieve something similar by defining a struct with a single element:

{% include “docs/reference/fidl/language/error-catalog/label/_good.md” %}

{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/good/fi-0062-a.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}

Alternatively, you can define an alias, but note that unlike a newtype this provides no type safety (that is, it can be used interchangeably with its underlying type):

{% include “docs/reference/fidl/language/error-catalog/label/_good.md” %}

{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/good/fi-0062-b.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}