tools/fidl/fidlgen_rust/codegen/union.tmpl

{{/*
// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
*/}}

{{- define "UnionDeclaration" }}
{{- range .DocComments}}
///{{ . }}
{{- end}}
{{ .Derives }}
pub enum {{ .Name }} {
    {{- range .Members }}
    {{- range .DocComments }}
    ///{{ . }}
    {{- end }}
    {{ .Name }}({{ .Type }}),
    {{- end }}
    {{- if .IsFlexible }}
    #[deprecated = "Use `{{ .Name }}::unknown()` to construct and `{{ .Name }}Unknown!()` to exhaustively match."]
    #[doc(hidden)]
    __Unknown {
        ordinal: u64,
        {{- if .IsResourceType }}
        data: fidl::UnknownData,
        {{- else }}
        bytes: Vec<u8>,
        {{- end }}
    },
    {{- end }}
}

{{- if .IsFlexible }}
/// Pattern that matches an unknown `{{ .Name }}` member.
#[macro_export]
macro_rules! {{ .Name }}Unknown {
    () => { _ };
}
{{- end }}

impl {{ .Name }} {
{{- if and .IsStrict .IsValueType }}
    #[deprecated = "Strict unions should not use `validate`"]
    #[inline]
    pub fn validate(self) -> std::result::Result<Self, (u64, Vec<u8>)> {
        Ok(self)
    }

    #[deprecated = "Strict unions should not use `is_unknown`"]
    #[inline]
    pub fn is_unknown(&self) -> bool {
        false
    }
{{- end }}

{{- if and .IsStrict .IsResourceType }}
    #[deprecated = "Strict unions should not use `validate`"]
    #[inline]
    pub fn validate(self) -> std::result::Result<Self, (u64, fidl::UnknownData)> {
        Ok(self)
    }

    #[deprecated = "Strict unions should not use `is_unknown`"]
    #[inline]
    pub fn is_unknown(&self) -> bool {
        false
    }
{{- end }}

{{- if and .IsFlexible .IsValueType }}
    #[inline]
    pub fn unknown(ordinal: u64, bytes: Vec<u8>) -> Self {
        #[allow(deprecated)]
        Self::__Unknown { ordinal, bytes }
    }

    #[inline]
    pub fn validate(self) -> std::result::Result<Self, (u64, Vec<u8>)> {
        match self {
            #[allow(deprecated)]
            Self::__Unknown { ordinal, bytes } => Err((ordinal, bytes)),
            {{- if .Members }}
            _ => Ok(self)
            {{- end }}
        }
    }

    #[inline]
    pub fn is_unknown(&self) -> bool {
        match self {
            #[allow(deprecated)]
            Self::__Unknown { .. } => true,
            {{- if .Members }}
            _ => false,
            {{- end }}
        }
    }
{{- end }}

{{- if and .IsFlexible .IsResourceType }}
    #[inline]
    pub fn unknown(ordinal: u64, data: fidl::UnknownData) -> Self {
        #[allow(deprecated)]
        Self::__Unknown { ordinal, data }
    }

    #[inline]
    pub fn validate(self) -> std::result::Result<Self, (u64, fidl::UnknownData)> {
        match self {
            #[allow(deprecated)]
            Self::__Unknown { ordinal, data } => Err((ordinal, data)),
            {{- if .Members }}
            _ => Ok(self)
            {{- end }}
        }
    }

    #[inline]
    pub fn is_unknown(&self) -> bool {
        match self {
            #[allow(deprecated)]
            Self::__Unknown { .. } => true,
            {{- if .Members }}
            _ => false,
            {{- end }}
        }
    }
{{- end }}
}

{{ if .IsValueType }}
impl fidl::encoding::Persistable for {{ .Name }} {}
{{- end }}

fidl_union! {
    name: {{ .Name }},
    members: [
    {{- range .Members }}
        {{ .Name }} {
            ty: {{ .Type }},
            ordinal: {{ .Ordinal }},
            {{- if .HasHandleMetadata }}
            handle_metadata: {
                handle_subtype: {{ .HandleSubtype }},
                handle_rights: {{ .HandleRights }},
            },
            {{- end }}
        },
    {{- end }}
    ],
    {{- if .IsFlexible }}
    {{ if .IsResourceType }}resource{{ else }}value{{ end }}_unknown_member: __Unknown,
    {{- end }}
}
{{ end }}