[TOC]

# fidl.test.union


## **PROTOCOLS**

## TestProtocol {#TestProtocol}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#127)*


### FlexibleXUnionHenceResponseMustBeHeapAllocated {#fidl.test.union/TestProtocol.FlexibleXUnionHenceResponseMustBeHeapAllocated}


#### Request
<table>
    <tr><th>Name</th><th>Type</th></tr>
    </table>


#### Response
<table>
    <tr><th>Name</th><th>Type</th></tr>
    <tr>
            <td><code>xu</code></td>
            <td>
                <code><a class='link' href='#OlderSimpleUnion'>OlderSimpleUnion</a></code>
            </td>
        </tr></table>

### StrictXUnionHenceResponseMayBeStackAllocated {#fidl.test.union/TestProtocol.StrictXUnionHenceResponseMayBeStackAllocated}


#### Request
<table>
    <tr><th>Name</th><th>Type</th></tr>
    </table>


#### Response
<table>
    <tr><th>Name</th><th>Type</th></tr>
    <tr>
            <td><code>xu</code></td>
            <td>
                <code><a class='link' href='#StrictBoundedXUnion'>StrictBoundedXUnion</a></code>
            </td>
        </tr></table>


## **STRUCTS**

### Empty {#Empty}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#114)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th><th>Default</th></tr>
</table>

### NullableUnionStruct {#NullableUnionStruct}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#66)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th><th>Default</th></tr><tr id="NullableUnionStruct.the_union">
            <td><code>the_union</code></td>
            <td>
                <code><a class='link' href='#Union'>Union</a>?</code>
            </td>
            <td></td>
            <td>No default</td>
        </tr>
</table>

### Pasta {#Pasta}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#7)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th><th>Default</th></tr><tr id="Pasta.sauce">
            <td><code>sauce</code></td>
            <td>
                <code>string[16]</code>
            </td>
            <td></td>
            <td>No default</td>
        </tr>
</table>

### Pizza {#Pizza}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#3)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th><th>Default</th></tr><tr id="Pizza.toppings">
            <td><code>toppings</code></td>
            <td>
                <code>vector&lt;string&gt;</code>
            </td>
            <td></td>
            <td>No default</td>
        </tr>
</table>

### StructWithNullableXUnion {#StructWithNullableXUnion}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#132)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th><th>Default</th></tr><tr id="StructWithNullableXUnion.x1">
            <td><code>x1</code></td>
            <td>
                <code><a class='link' href='#OlderSimpleUnion'>OlderSimpleUnion</a>?</code>
            </td>
            <td></td>
            <td>No default</td>
        </tr>
</table>


## **UNIONS**

### ExplicitFoo {#ExplicitFoo}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#80)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="ExplicitFoo.s">
            <td><code>s</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
        </tr><tr id="ExplicitFoo.i">
            <td><code>i</code></td>
            <td>
                <code>int32</code>
            </td>
            <td></td>
        </tr><tr id="ExplicitFoo.">
            <td><code></code></td>
            <td>
                <code></code>
            </td>
            <td></td>
        </tr></table>

### ExplicitPizzaOrPasta {#ExplicitPizzaOrPasta}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#16)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="ExplicitPizzaOrPasta.">
            <td><code></code></td>
            <td>
                <code></code>
            </td>
            <td></td>
        </tr><tr id="ExplicitPizzaOrPasta.">
            <td><code></code></td>
            <td>
                <code></code>
            </td>
            <td></td>
        </tr><tr id="ExplicitPizzaOrPasta.pizza">
            <td><code>pizza</code></td>
            <td>
                <code><a class='link' href='#Pizza'>Pizza</a></code>
            </td>
            <td></td>
        </tr><tr id="ExplicitPizzaOrPasta.pasta">
            <td><code>pasta</code></td>
            <td>
                <code><a class='link' href='#Pasta'>Pasta</a></code>
            </td>
            <td></td>
        </tr></table>

### ExplicitStrictFoo {#ExplicitStrictFoo}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#86)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="ExplicitStrictFoo.">
            <td><code></code></td>
            <td>
                <code></code>
            </td>
            <td></td>
        </tr><tr id="ExplicitStrictFoo.s">
            <td><code>s</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
        </tr><tr id="ExplicitStrictFoo.i">
            <td><code>i</code></td>
            <td>
                <code>int32</code>
            </td>
            <td></td>
        </tr></table>

### ExplicitUnion {#ExplicitUnion}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#55)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="ExplicitUnion.">
            <td><code></code></td>
            <td>
                <code></code>
            </td>
            <td></td>
        </tr><tr id="ExplicitUnion.Primitive">
            <td><code>Primitive</code></td>
            <td>
                <code>int32</code>
            </td>
            <td></td>
        </tr><tr id="ExplicitUnion.StringNeedsConstructor">
            <td><code>StringNeedsConstructor</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
        </tr></table>

### ExplicitXUnion {#ExplicitXUnion}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#136)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="ExplicitXUnion.">
            <td><code></code></td>
            <td>
                <code></code>
            </td>
            <td></td>
        </tr><tr id="ExplicitXUnion.">
            <td><code></code></td>
            <td>
                <code></code>
            </td>
            <td></td>
        </tr><tr id="ExplicitXUnion.i">
            <td><code>i</code></td>
            <td>
                <code>int64</code>
            </td>
            <td></td>
        </tr><tr id="ExplicitXUnion.f">
            <td><code>f</code></td>
            <td>
                <code>float32</code>
            </td>
            <td></td>
        </tr></table>

### FieldCollision {#FieldCollision}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#51)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="FieldCollision.field_collision_tag">
            <td><code>field_collision_tag</code></td>
            <td>
                <code>int32</code>
            </td>
            <td></td>
        </tr></table>

### FlexibleFoo {#FlexibleFoo}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#70)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="FlexibleFoo.s">
            <td><code>s</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
        </tr><tr id="FlexibleFoo.i">
            <td><code>i</code></td>
            <td>
                <code>int32</code>
            </td>
            <td></td>
        </tr></table>

### FlexiblePizzaOrPasta {#FlexiblePizzaOrPasta}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#23)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="FlexiblePizzaOrPasta.pizza">
            <td><code>pizza</code></td>
            <td>
                <code><a class='link' href='#Pizza'>Pizza</a></code>
            </td>
            <td></td>
        </tr><tr id="FlexiblePizzaOrPasta.pasta">
            <td><code>pasta</code></td>
            <td>
                <code><a class='link' href='#Pasta'>Pasta</a></code>
            </td>
            <td></td>
        </tr></table>

### FlexibleUnion {#FlexibleUnion}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#39)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="FlexibleUnion.Primitive">
            <td><code>Primitive</code></td>
            <td>
                <code>int32</code>
            </td>
            <td></td>
        </tr><tr id="FlexibleUnion.StringNeedsConstructor">
            <td><code>StringNeedsConstructor</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
        </tr><tr id="FlexibleUnion.VectorStringAlsoNeedsConstructor">
            <td><code>VectorStringAlsoNeedsConstructor</code></td>
            <td>
                <code>vector&lt;string&gt;</code>
            </td>
            <td></td>
        </tr></table>

### NewerSimpleUnion {#NewerSimpleUnion}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#97)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="NewerSimpleUnion.i">
            <td><code>i</code></td>
            <td>
                <code>int64</code>
            </td>
            <td></td>
        </tr><tr id="NewerSimpleUnion.s">
            <td><code>s</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
        </tr><tr id="NewerSimpleUnion.v">
            <td><code>v</code></td>
            <td>
                <code>vector&lt;string&gt;</code>
            </td>
            <td></td>
        </tr></table>

### OlderSimpleUnion {#OlderSimpleUnion}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#92)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="OlderSimpleUnion.i">
            <td><code>i</code></td>
            <td>
                <code>int64</code>
            </td>
            <td></td>
        </tr><tr id="OlderSimpleUnion.f">
            <td><code>f</code></td>
            <td>
                <code>float32</code>
            </td>
            <td></td>
        </tr></table>

### PizzaOrPasta {#PizzaOrPasta}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#11)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="PizzaOrPasta.pizza">
            <td><code>pizza</code></td>
            <td>
                <code><a class='link' href='#Pizza'>Pizza</a></code>
            </td>
            <td></td>
        </tr><tr id="PizzaOrPasta.pasta">
            <td><code>pasta</code></td>
            <td>
                <code><a class='link' href='#Pasta'>Pasta</a></code>
            </td>
            <td></td>
        </tr></table>

### ReverseOrdinalUnion {#ReverseOrdinalUnion}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#61)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="ReverseOrdinalUnion.second">
            <td><code>second</code></td>
            <td>
                <code>uint32</code>
            </td>
            <td></td>
        </tr><tr id="ReverseOrdinalUnion.first">
            <td><code>first</code></td>
            <td>
                <code>uint32</code>
            </td>
            <td></td>
        </tr></table>

### StrictBoundedXUnion {#StrictBoundedXUnion}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#123)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="StrictBoundedXUnion.v">
            <td><code>v</code></td>
            <td>
                <code>vector&lt;uint8&gt;[10]</code>
            </td>
            <td></td>
        </tr></table>

### StrictFoo {#StrictFoo}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#75)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="StrictFoo.s">
            <td><code>s</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
        </tr><tr id="StrictFoo.i">
            <td><code>i</code></td>
            <td>
                <code>int32</code>
            </td>
            <td></td>
        </tr></table>

### StrictPizzaOrPasta {#StrictPizzaOrPasta}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#28)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="StrictPizzaOrPasta.pizza">
            <td><code>pizza</code></td>
            <td>
                <code><a class='link' href='#Pizza'>Pizza</a></code>
            </td>
            <td></td>
        </tr><tr id="StrictPizzaOrPasta.pasta">
            <td><code>pasta</code></td>
            <td>
                <code><a class='link' href='#Pasta'>Pasta</a></code>
            </td>
            <td></td>
        </tr></table>

### StrictSimpleXUnion {#StrictSimpleXUnion}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#108)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="StrictSimpleXUnion.i">
            <td><code>i</code></td>
            <td>
                <code>int32</code>
            </td>
            <td></td>
        </tr><tr id="StrictSimpleXUnion.f">
            <td><code>f</code></td>
            <td>
                <code>float32</code>
            </td>
            <td></td>
        </tr><tr id="StrictSimpleXUnion.s">
            <td><code>s</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
        </tr></table>

### StrictUnion {#StrictUnion}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#45)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="StrictUnion.Primitive">
            <td><code>Primitive</code></td>
            <td>
                <code>int32</code>
            </td>
            <td></td>
        </tr><tr id="StrictUnion.StringNeedsConstructor">
            <td><code>StringNeedsConstructor</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
        </tr><tr id="StrictUnion.VectorStringAlsoNeedsConstructor">
            <td><code>VectorStringAlsoNeedsConstructor</code></td>
            <td>
                <code>vector&lt;string&gt;</code>
            </td>
            <td></td>
        </tr></table>

### Union {#Union}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#33)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="Union.Primitive">
            <td><code>Primitive</code></td>
            <td>
                <code>int32</code>
            </td>
            <td></td>
        </tr><tr id="Union.StringNeedsConstructor">
            <td><code>StringNeedsConstructor</code></td>
            <td>
                <code>string</code>
            </td>
            <td></td>
        </tr><tr id="Union.VectorStringAlsoNeedsConstructor">
            <td><code>VectorStringAlsoNeedsConstructor</code></td>
            <td>
                <code>vector&lt;string&gt;</code>
            </td>
            <td></td>
        </tr></table>

### XUnionContainingEmptyStruct {#XUnionContainingEmptyStruct}
*Defined in [fidl.test.union/union.test.fidl](https://fuchsia.googlesource.com/fuchsia/+/master/zircon/tools/fidl/testdata/union.test.fidl#117)*


<table>
    <tr><th>Name</th><th>Type</th><th>Description</th></tr><tr id="XUnionContainingEmptyStruct.empty">
            <td><code>empty</code></td>
            <td>
                <code><a class='link' href='#Empty'>Empty</a></code>
            </td>
            <td></td>
        </tr></table>