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Module `0x1::any`

aptos-move/framework/aptos-stdlib/doc/any.md

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<a id="0x1_any"></a>

Module 0x1::any

<pre><code><b>use</b> <a href="../../move-stdlib/doc/bcs.md#0x1_bcs">0x1::bcs</a>; <b>use</b> <a href="from_bcs.md#0x1_from_bcs">0x1::from_bcs</a>; <b>use</b> <a href="../../move-stdlib/doc/string.md#0x1_string">0x1::string</a>; <b>use</b> <a href="type_info.md#0x1_type_info">0x1::type_info</a>; </code></pre>

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Struct Any

A type which can represent a value of any type. This allows for representation of 'unknown' future values. For example, to define a resource such that it can be later be extended without breaking changes one can do

move
struct Resource {
field: Type,
...
extension: Option<Any>
}
<pre><code><b>struct</b> <a href="any.md#0x1_any_Any">Any</a> <b>has</b> drop, store </code></pre> <details> <summary>Fields</summary> <dl> <dt> <code>type_name: <a href="../../move-stdlib/doc/string.md#0x1_string_String">string::String</a></code> </dt> <dd> </dd> <dt> <code>data: <a href="../../move-stdlib/doc/vector.md#0x1_vector">vector</a>&lt;u8&gt;</code> </dt> <dd> </dd> </dl> </details>

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Constants

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The type provided for <code>unpack</code> is not the same as was given for <code>pack</code>.

<pre><code><b>const</b> <a href="any.md#0x1_any_ETYPE_MISMATCH">ETYPE_MISMATCH</a>: u64 = 1; </code></pre>

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Function pack

Pack a value into the <code><a href="any.md#0x1_any_Any">Any</a></code> representation. Because Any can be stored and dropped, this is also required from <code>T</code>.

<pre><code><b>public</b> <b>fun</b> <a href="any.md#0x1_any_pack">pack</a>&lt;T: drop, store&gt;(x: T): <a href="any.md#0x1_any_Any">any::Any</a> </code></pre> <details> <summary>Implementation</summary> <pre><code><b>public</b> <b>fun</b> <a href="any.md#0x1_any_pack">pack</a>&lt;T: drop + store&gt;(x: T): <a href="any.md#0x1_any_Any">Any</a> { <a href="any.md#0x1_any_Any">Any</a> { type_name: <a href="type_info.md#0x1_type_info_type_name">type_info::type_name</a>&lt;T&gt;(), data: to_bytes(&x) } } </code></pre> </details>

<a id="0x1_any_unpack"></a>

Function unpack

Unpack a value from the <code><a href="any.md#0x1_any_Any">Any</a></code> representation. This aborts if the value has not the expected type <code>T</code>.

<pre><code><b>public</b> <b>fun</b> <a href="any.md#0x1_any_unpack">unpack</a>&lt;T&gt;(self: <a href="any.md#0x1_any_Any">any::Any</a>): T </code></pre> <details> <summary>Implementation</summary> <pre><code><b>public</b> <b>fun</b> <a href="any.md#0x1_any_unpack">unpack</a>&lt;T&gt;(self: <a href="any.md#0x1_any_Any">Any</a>): T { <b>assert</b>!(<a href="type_info.md#0x1_type_info_type_name">type_info::type_name</a>&lt;T&gt;() == self.type_name, <a href="../../move-stdlib/doc/error.md#0x1_error_invalid_argument">error::invalid_argument</a>(<a href="any.md#0x1_any_ETYPE_MISMATCH">ETYPE_MISMATCH</a>)); from_bytes&lt;T&gt;(self.data) } </code></pre> </details>

<a id="0x1_any_type_name"></a>

Function type_name

Returns the type name of this Any

<pre><code><b>public</b> <b>fun</b> <a href="any.md#0x1_any_type_name">type_name</a>(self: &<a href="any.md#0x1_any_Any">any::Any</a>): &<a href="../../move-stdlib/doc/string.md#0x1_string_String">string::String</a> </code></pre> <details> <summary>Implementation</summary> <pre><code><b>public</b> <b>fun</b> <a href="any.md#0x1_any_type_name">type_name</a>(self: &<a href="any.md#0x1_any_Any">Any</a>): &String { &self.type_name } </code></pre> </details>

<a id="@Specification_1"></a>

Specification

<a id="@Specification_1_pack"></a>

Function pack

<pre><code><b>public</b> <b>fun</b> <a href="any.md#0x1_any_pack">pack</a>&lt;T: drop, store&gt;(x: T): <a href="any.md#0x1_any_Any">any::Any</a> </code></pre> <pre><code><b>aborts_if</b> <b>false</b>; <b>ensures</b> result == <a href="any.md#0x1_any_Any">Any</a> { type_name: <a href="type_info.md#0x1_type_info_type_name">type_info::type_name</a>&lt;T&gt;(), data: <a href="../../move-stdlib/doc/bcs.md#0x1_bcs_serialize">bcs::serialize</a>&lt;T&gt;(x) }; <b>ensures</b> [abstract] <a href="from_bcs.md#0x1_from_bcs_deserializable">from_bcs::deserializable</a>&lt;T&gt;(result.data); </code></pre>

<a id="@Specification_1_unpack"></a>

Function unpack

<pre><code><b>public</b> <b>fun</b> <a href="any.md#0x1_any_unpack">unpack</a>&lt;T&gt;(self: <a href="any.md#0x1_any_Any">any::Any</a>): T </code></pre> <pre><code><b>include</b> <a href="any.md#0x1_any_UnpackAbortsIf">UnpackAbortsIf</a>&lt;T&gt;; <b>ensures</b> result == <a href="from_bcs.md#0x1_from_bcs_deserialize">from_bcs::deserialize</a>&lt;T&gt;(self.data); </code></pre>

<a id="0x1_any_UnpackAbortsIf"></a>

<pre><code><b>schema</b> <a href="any.md#0x1_any_UnpackAbortsIf">UnpackAbortsIf</a>&lt;T&gt; { self: <a href="any.md#0x1_any_Any">Any</a>; <b>aborts_if</b> <a href="type_info.md#0x1_type_info_type_name">type_info::type_name</a>&lt;T&gt;() != self.type_name; <b>aborts_if</b> !<a href="from_bcs.md#0x1_from_bcs_deserializable">from_bcs::deserializable</a>&lt;T&gt;(self.data); } </code></pre>

<a id="0x1_any_UnpackRequirement"></a>

<pre><code><b>schema</b> <a href="any.md#0x1_any_UnpackRequirement">UnpackRequirement</a>&lt;T&gt; { self: <a href="any.md#0x1_any_Any">Any</a>; <b>requires</b> <a href="type_info.md#0x1_type_info_type_name">type_info::type_name</a>&lt;T&gt;() == self.type_name; <b>requires</b> <a href="from_bcs.md#0x1_from_bcs_deserializable">from_bcs::deserializable</a>&lt;T&gt;(self.data); } </code></pre>

<a id="@Specification_1_type_name"></a>

Function type_name

<pre><code><b>public</b> <b>fun</b> <a href="any.md#0x1_any_type_name">type_name</a>(self: &<a href="any.md#0x1_any_Any">any::Any</a>): &<a href="../../move-stdlib/doc/string.md#0x1_string_String">string::String</a> </code></pre> <pre><code><b>aborts_if</b> <b>false</b>; <b>ensures</b> result == self.type_name; </code></pre>