Module `std::option`

This module defines the Option type and its methods to represent and handle an optional value.

Struct Option
Constants
Function none
Function some
Function is_none
Function is_some
Function contains
Function borrow
Function borrow_with_default
Function get_with_default
Function fill
Function extract
Function borrow_mut
Function swap
Function swap_or_fill
Function destroy_with_default
Function destroy_some
Function destroy_none
Function to_vec
Macro function destroy
Macro function do
Macro function do_ref
Macro function do_mut
Macro function or
Macro function and
Macro function and_ref
Macro function map
Macro function map_ref
Macro function filter
Macro function is_some_and
Macro function extract_or
Macro function destroy_or

<pre><code>use <a href="../std/vector.md#std_vector">std::vector</a>; </code></pre>

Struct `Option`

Abstraction of a value that may or may not be present. Implemented with a vector of size zero or one because Move bytecode does not have ADTs.

<pre><code>public struct <a href="../std/option.md#std_option_Option">Option</a><Element> has copy, drop, store </code></pre> <details> <summary>Fields</summary> <dl> <dt> <code>vec: <a href="../std/vector.md#std_vector">vector</a><Element></code> </dt> <dd> </dd> </dl> </details>

Constants

The <code><a href="../std/option.md#std_option_Option">Option</a></code> is in an invalid state for the operation attempted. The <code><a href="../std/option.md#std_option_Option">Option</a></code> is <code>Some</code> while it should be <code>None</code>.

<pre><code>const <a href="../std/option.md#std_option_EOPTION_IS_SET">EOPTION_IS_SET</a>: <a href="../std/u64.md#std_u64">u64</a> = 262144; </code></pre>

<pre><code>const <a href="../std/option.md#std_option_EOPTION_NOT_SET">EOPTION_NOT_SET</a>: <a href="../std/u64.md#std_u64">u64</a> = 262145; </code></pre>

Function `none`

Return an empty <code><a href="../std/option.md#std_option_Option">Option</a></code>

<pre><code>public fun <a href="../std/option.md#std_option_none">none</a><Element>(): <a href="../std/option.md#std_option_Option">std::option::Option</a><Element> </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_none">none</a><Element>(): <a href="../std/option.md#std_option_Option">Option</a><Element> { <a href="../std/option.md#std_option_Option">Option</a> { vec: <a href="../std/vector.md#std_vector_empty">vector::empty</a>() } } </code></pre> </details>

Function `some`

Return an <code><a href="../std/option.md#std_option_Option">Option</a></code> containing <code>e</code>

<pre><code>public fun <a href="../std/option.md#std_option_some">some</a><Element>(e: Element): <a href="../std/option.md#std_option_Option">std::option::Option</a><Element> </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_some">some</a><Element>(e: Element): <a href="../std/option.md#std_option_Option">Option</a><Element> { <a href="../std/option.md#std_option_Option">Option</a> { vec: <a href="../std/vector.md#std_vector_singleton">vector::singleton</a>(e) } } </code></pre> </details>

Function `is_none`

Return true if <code>t</code> does not hold a value

<pre><code>public fun <a href="../std/option.md#std_option_is_none">is_none</a><Element>(t: &<a href="../std/option.md#std_option_Option">std::option::Option</a><Element>): <a href="../std/bool.md#std_bool">bool</a> </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_is_none">is_none</a><Element>(t: &<a href="../std/option.md#std_option_Option">Option</a><Element>): <a href="../std/bool.md#std_bool">bool</a> { t.vec.is_empty() } </code></pre> </details>

Function `is_some`

Return true if <code>t</code> holds a value

<pre><code>public fun <a href="../std/option.md#std_option_is_some">is_some</a><Element>(t: &<a href="../std/option.md#std_option_Option">std::option::Option</a><Element>): <a href="../std/bool.md#std_bool">bool</a> </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_is_some">is_some</a><Element>(t: &<a href="../std/option.md#std_option_Option">Option</a><Element>): <a href="../std/bool.md#std_bool">bool</a> { !t.vec.is_empty() } </code></pre> </details>

Function `contains`

Return true if the value in <code>t</code> is equal to <code>e_ref</code> Always returns <code>false</code> if <code>t</code> does not hold a value

<pre><code>public fun <a href="../std/option.md#std_option_contains">contains</a><Element>(t: &<a href="../std/option.md#std_option_Option">std::option::Option</a><Element>, e_ref: &Element): <a href="../std/bool.md#std_bool">bool</a> </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_contains">contains</a><Element>(t: &<a href="../std/option.md#std_option_Option">Option</a><Element>, e_ref: &Element): <a href="../std/bool.md#std_bool">bool</a> { t.vec.<a href="../std/option.md#std_option_contains">contains</a>(e_ref) } </code></pre> </details>

Function `borrow`

Return an immutable reference to the value inside <code>t</code> Aborts if <code>t</code> does not hold a value

<pre><code>public fun <a href="../std/option.md#std_option_borrow">borrow</a><Element>(t: &<a href="../std/option.md#std_option_Option">std::option::Option</a><Element>): &Element </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_borrow">borrow</a><Element>(t: &<a href="../std/option.md#std_option_Option">Option</a><Element>): &Element { assert!(t.<a href="../std/option.md#std_option_is_some">is_some</a>(), <a href="../std/option.md#std_option_EOPTION_NOT_SET">EOPTION_NOT_SET</a>); &t.vec[0] } </code></pre> </details>

Function `borrow_with_default`

Return a reference to the value inside <code>t</code> if it holds one Return <code>default_ref</code> if <code>t</code> does not hold a value

<pre><code>public fun <a href="../std/option.md#std_option_borrow_with_default">borrow_with_default</a><Element>(t: &<a href="../std/option.md#std_option_Option">std::option::Option</a><Element>, default_ref: &Element): &Element </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_borrow_with_default">borrow_with_default</a><Element>(t: &<a href="../std/option.md#std_option_Option">Option</a><Element>, default_ref: &Element): &Element { let vec_ref = &t.vec; if (vec_ref.is_empty()) default_ref else &vec_ref[0] } </code></pre> </details>

Function `get_with_default`

Return the value inside <code>t</code> if it holds one Return <code>default</code> if <code>t</code> does not hold a value

<pre><code>public fun <a href="../std/option.md#std_option_get_with_default">get_with_default</a><Element: copy, drop>(t: &<a href="../std/option.md#std_option_Option">std::option::Option</a><Element>, default: Element): Element </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_get_with_default">get_with_default</a><Element: copy + drop>(t: &<a href="../std/option.md#std_option_Option">Option</a><Element>, default: Element): Element { let vec_ref = &t.vec; if (vec_ref.is_empty()) default else vec_ref[0] } </code></pre> </details>

Function `fill`

Convert the none option <code>t</code> to a some option by adding <code>e</code>. Aborts if <code>t</code> already holds a value

<pre><code>public fun <a href="../std/option.md#std_option_fill">fill</a><Element>(t: &mut <a href="../std/option.md#std_option_Option">std::option::Option</a><Element>, e: Element) </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_fill">fill</a><Element>(t: &mut <a href="../std/option.md#std_option_Option">Option</a><Element>, e: Element) { let vec_ref = &mut t.vec; if (vec_ref.is_empty()) vec_ref.push_back(e) else abort <a href="../std/option.md#std_option_EOPTION_IS_SET">EOPTION_IS_SET</a> } </code></pre> </details>

Function `extract`

Convert a <code><a href="../std/option.md#std_option_some">some</a></code> option to a <code><a href="../std/option.md#std_option_none">none</a></code> by removing and returning the value stored inside <code>t</code> Aborts if <code>t</code> does not hold a value

<pre><code>public fun <a href="../std/option.md#std_option_extract">extract</a><Element>(t: &mut <a href="../std/option.md#std_option_Option">std::option::Option</a><Element>): Element </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_extract">extract</a><Element>(t: &mut <a href="../std/option.md#std_option_Option">Option</a><Element>): Element { assert!(t.<a href="../std/option.md#std_option_is_some">is_some</a>(), <a href="../std/option.md#std_option_EOPTION_NOT_SET">EOPTION_NOT_SET</a>); t.vec.pop_back() } </code></pre> </details>

Function `borrow_mut`

Return a mutable reference to the value inside <code>t</code> Aborts if <code>t</code> does not hold a value

<pre><code>public fun <a href="../std/option.md#std_option_borrow_mut">borrow_mut</a><Element>(t: &mut <a href="../std/option.md#std_option_Option">std::option::Option</a><Element>): &mut Element </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_borrow_mut">borrow_mut</a><Element>(t: &mut <a href="../std/option.md#std_option_Option">Option</a><Element>): &mut Element { assert!(t.<a href="../std/option.md#std_option_is_some">is_some</a>(), <a href="../std/option.md#std_option_EOPTION_NOT_SET">EOPTION_NOT_SET</a>); &mut t.vec[0] } </code></pre> </details>

Function `swap`

Swap the old value inside <code>t</code> with <code>e</code> and return the old value Aborts if <code>t</code> does not hold a value

<pre><code>public fun <a href="../std/option.md#std_option_swap">swap</a><Element>(t: &mut <a href="../std/option.md#std_option_Option">std::option::Option</a><Element>, e: Element): Element </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_swap">swap</a><Element>(t: &mut <a href="../std/option.md#std_option_Option">Option</a><Element>, e: Element): Element { assert!(t.<a href="../std/option.md#std_option_is_some">is_some</a>(), <a href="../std/option.md#std_option_EOPTION_NOT_SET">EOPTION_NOT_SET</a>); let vec_ref = &mut t.vec; let old_value = vec_ref.pop_back(); vec_ref.push_back(e); old_value } </code></pre> </details>

Function `swap_or_fill`

Swap the old value inside <code>t</code> with <code>e</code> and return the old value; or if there is no old value, fill it with <code>e</code>. Different from swap(), swap_or_fill() allows for <code>t</code> not holding a value.

<pre><code>public fun <a href="../std/option.md#std_option_swap_or_fill">swap_or_fill</a><Element>(t: &mut <a href="../std/option.md#std_option_Option">std::option::Option</a><Element>, e: Element): <a href="../std/option.md#std_option_Option">std::option::Option</a><Element> </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_swap_or_fill">swap_or_fill</a><Element>(t: &mut <a href="../std/option.md#std_option_Option">Option</a><Element>, e: Element): <a href="../std/option.md#std_option_Option">Option</a><Element> { let vec_ref = &mut t.vec; let old_value = if (vec_ref.is_empty()) <a href="../std/option.md#std_option_none">none</a>() else <a href="../std/option.md#std_option_some">some</a>(vec_ref.pop_back()); vec_ref.push_back(e); old_value } </code></pre> </details>

Function `destroy_with_default`

Destroys <code>t.</code> If <code>t</code> holds a value, return it. Returns <code>default</code> otherwise

<pre><code>public fun <a href="../std/option.md#std_option_destroy_with_default">destroy_with_default</a><Element: drop>(t: <a href="../std/option.md#std_option_Option">std::option::Option</a><Element>, default: Element): Element </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_destroy_with_default">destroy_with_default</a><Element: drop>(t: <a href="../std/option.md#std_option_Option">Option</a><Element>, default: Element): Element { let <a href="../std/option.md#std_option_Option">Option</a> { mut vec } = t; if (vec.is_empty()) default else vec.pop_back() } </code></pre> </details>

Function `destroy_some`

Unpack <code>t</code> and return its contents Aborts if <code>t</code> does not hold a value

<pre><code>public fun <a href="../std/option.md#std_option_destroy_some">destroy_some</a><Element>(t: <a href="../std/option.md#std_option_Option">std::option::Option</a><Element>): Element </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_destroy_some">destroy_some</a><Element>(t: <a href="../std/option.md#std_option_Option">Option</a><Element>): Element { assert!(t.<a href="../std/option.md#std_option_is_some">is_some</a>(), <a href="../std/option.md#std_option_EOPTION_NOT_SET">EOPTION_NOT_SET</a>); let <a href="../std/option.md#std_option_Option">Option</a> { mut vec } = t; let elem = vec.pop_back(); vec.destroy_empty(); elem } </code></pre> </details>

Function `destroy_none`

Unpack <code>t</code> Aborts if <code>t</code> holds a value

<pre><code>public fun <a href="../std/option.md#std_option_destroy_none">destroy_none</a><Element>(t: <a href="../std/option.md#std_option_Option">std::option::Option</a><Element>) </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_destroy_none">destroy_none</a><Element>(t: <a href="../std/option.md#std_option_Option">Option</a><Element>) { assert!(t.<a href="../std/option.md#std_option_is_none">is_none</a>(), <a href="../std/option.md#std_option_EOPTION_IS_SET">EOPTION_IS_SET</a>); let <a href="../std/option.md#std_option_Option">Option</a> { vec } = t; vec.destroy_empty() } </code></pre> </details>

Function `to_vec`

Convert <code>t</code> into a vector of length 1 if it is <code>Some</code>, and an empty vector otherwise

<pre><code>public fun <a href="../std/option.md#std_option_to_vec">to_vec</a><Element>(t: <a href="../std/option.md#std_option_Option">std::option::Option</a><Element>): <a href="../std/vector.md#std_vector">vector</a><Element> </code></pre> <details> <summary>Implementation</summary> <pre><code>public fun <a href="../std/option.md#std_option_to_vec">to_vec</a><Element>(t: <a href="../std/option.md#std_option_Option">Option</a><Element>): <a href="../std/vector.md#std_vector">vector</a><Element> { let <a href="../std/option.md#std_option_Option">Option</a> { vec } = t; vec } </code></pre> </details>

Macro function `destroy`

Destroy <code><a href="../std/option.md#std_option_Option">Option</a><T></code> and call the closure <code>f</code> on the value inside if it holds one.

<pre><code>public macro fun <a href="../std/option.md#std_option_destroy">destroy</a><$T, $R: drop>($o: <a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $f: |$T| -> $R) </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_destroy">destroy</a><$T, $R: drop>($o: <a href="../std/option.md#std_option_Option">Option</a><$T>, $f: |$T| -> $R) { let o = $o; o.<a href="../std/option.md#std_option_do">do</a>!($f); } </code></pre> </details>

Macro function `do`

Destroy <code><a href="../std/option.md#std_option_Option">Option</a><T></code> and call the closure <code>f</code> on the value inside if it holds one.

<pre><code>public macro fun <a href="../std/option.md#std_option_do">do</a><$T, $R: drop>($o: <a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $f: |$T| -> $R) </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_do">do</a><$T, $R: drop>($o: <a href="../std/option.md#std_option_Option">Option</a><$T>, $f: |$T| -> $R) { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>()) { $f(o.<a href="../std/option.md#std_option_destroy_some">destroy_some</a>()); } else o.<a href="../std/option.md#std_option_destroy_none">destroy_none</a>() } </code></pre> </details>

Macro function `do_ref`

Execute a closure on the value inside <code>t</code> if it holds one.

<pre><code>public macro fun <a href="../std/option.md#std_option_do_ref">do_ref</a><$T, $R: drop>($o: &<a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $f: |&$T| -> $R) </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_do_ref">do_ref</a><$T, $R: drop>($o: &<a href="../std/option.md#std_option_Option">Option</a><$T>, $f: |&$T| -> $R) { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>()) { $f(o.<a href="../std/option.md#std_option_borrow">borrow</a>()); } } </code></pre> </details>

Macro function `do_mut`

Execute a closure on the mutable reference to the value inside <code>t</code> if it holds one.

<pre><code>public macro fun <a href="../std/option.md#std_option_do_mut">do_mut</a><$T, $R: drop>($o: &mut <a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $f: |&mut $T| -> $R) </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_do_mut">do_mut</a><$T, $R: drop>($o: &mut <a href="../std/option.md#std_option_Option">Option</a><$T>, $f: |&mut $T| -> $R) { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>()) { $f(o.<a href="../std/option.md#std_option_borrow_mut">borrow_mut</a>()); } } </code></pre> </details>

Macro function `or`

Select the first <code>Some</code> value from the two options, or <code>None</code> if both are <code>None</code>. Equivalent to Rust's <code>a.<a href="../std/option.md#std_option_or">or</a>(b)</code>.

<pre><code>public macro fun <a href="../std/option.md#std_option_or">or</a><$T>($o: <a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $default: <a href="../std/option.md#std_option_Option">std::option::Option</a><$T>): <a href="../std/option.md#std_option_Option">std::option::Option</a><$T> </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_or">or</a><$T>($o: <a href="../std/option.md#std_option_Option">Option</a><$T>, $default: <a href="../std/option.md#std_option_Option">Option</a><$T>): <a href="../std/option.md#std_option_Option">Option</a><$T> { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>()) { o } else { o.<a href="../std/option.md#std_option_destroy_none">destroy_none</a>(); $default } } </code></pre> </details>

Macro function `and`

If the value is <code>Some</code>, call the closure <code>f</code> on it. Otherwise, return <code>None</code>. Equivalent to Rust's <code>t.and_then(f)</code>.

<pre><code>public macro fun <a href="../std/option.md#std_option_and">and</a><$T, $U>($o: <a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $f: |$T| -> <a href="../std/option.md#std_option_Option">std::option::Option</a><$U>): <a href="../std/option.md#std_option_Option">std::option::Option</a><$U> </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_and">and</a><$T, $U>($o: <a href="../std/option.md#std_option_Option">Option</a><$T>, $f: |$T| -> <a href="../std/option.md#std_option_Option">Option</a><$U>): <a href="../std/option.md#std_option_Option">Option</a><$U> { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>()) { $f(o.<a href="../std/option.md#std_option_destroy_some">destroy_some</a>()) } else { o.<a href="../std/option.md#std_option_destroy_none">destroy_none</a>(); <a href="../std/option.md#std_option_none">none</a>() } } </code></pre> </details>

Macro function `and_ref`

If the value is <code>Some</code>, call the closure <code>f</code> on it. Otherwise, return <code>None</code>. Equivalent to Rust's <code>t.and_then(f)</code>.

<pre><code>public macro fun <a href="../std/option.md#std_option_and_ref">and_ref</a><$T, $U>($o: &<a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $f: |&$T| -> <a href="../std/option.md#std_option_Option">std::option::Option</a><$U>): <a href="../std/option.md#std_option_Option">std::option::Option</a><$U> </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_and_ref">and_ref</a><$T, $U>($o: &<a href="../std/option.md#std_option_Option">Option</a><$T>, $f: |&$T| -> <a href="../std/option.md#std_option_Option">Option</a><$U>): <a href="../std/option.md#std_option_Option">Option</a><$U> { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>()) $f(o.<a href="../std/option.md#std_option_borrow">borrow</a>()) else <a href="../std/option.md#std_option_none">none</a>() } </code></pre> </details>

Macro function `map`

Map an <code><a href="../std/option.md#std_option_Option">Option</a><T></code> to <code><a href="../std/option.md#std_option_Option">Option</a></code> by applying a function to a contained value. Equivalent to Rust's <code>t.<a href="../std/option.md#std_option_map">map</a>(f)</code>.

<pre><code>public macro fun <a href="../std/option.md#std_option_map">map</a><$T, $U>($o: <a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $f: |$T| -> $U): <a href="../std/option.md#std_option_Option">std::option::Option</a><$U> </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_map">map</a><$T, $U>($o: <a href="../std/option.md#std_option_Option">Option</a><$T>, $f: |$T| -> $U): <a href="../std/option.md#std_option_Option">Option</a><$U> { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>()) { <a href="../std/option.md#std_option_some">some</a>($f(o.<a href="../std/option.md#std_option_destroy_some">destroy_some</a>())) } else { o.<a href="../std/option.md#std_option_destroy_none">destroy_none</a>(); <a href="../std/option.md#std_option_none">none</a>() } } </code></pre> </details>

Macro function `map_ref`

Map an <code><a href="../std/option.md#std_option_Option">Option</a><T></code> value to <code><a href="../std/option.md#std_option_Option">Option</a></code> by applying a function to a contained value by reference. Original <code><a href="../std/option.md#std_option_Option">Option</a><T></code> is preserved. Equivalent to Rust's <code>t.<a href="../std/option.md#std_option_map">map</a>(f)</code>.

<pre><code>public macro fun <a href="../std/option.md#std_option_map_ref">map_ref</a><$T, $U>($o: &<a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $f: |&$T| -> $U): <a href="../std/option.md#std_option_Option">std::option::Option</a><$U> </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_map_ref">map_ref</a><$T, $U>($o: &<a href="../std/option.md#std_option_Option">Option</a><$T>, $f: |&$T| -> $U): <a href="../std/option.md#std_option_Option">Option</a><$U> { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>()) <a href="../std/option.md#std_option_some">some</a>($f(o.<a href="../std/option.md#std_option_borrow">borrow</a>())) else <a href="../std/option.md#std_option_none">none</a>() } </code></pre> </details>

Macro function `filter`

Return <code>None</code> if the value is <code>None</code>, otherwise return <code><a href="../std/option.md#std_option_Option">Option</a><T></code> if the predicate <code>f</code> returns true.

<pre><code>public macro fun <a href="../std/option.md#std_option_filter">filter</a><$T: drop>($o: <a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $f: |&$T| -> <a href="../std/bool.md#std_bool">bool</a>): <a href="../std/option.md#std_option_Option">std::option::Option</a><$T> </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_filter">filter</a><$T: drop>($o: <a href="../std/option.md#std_option_Option">Option</a><$T>, $f: |&$T| -> <a href="../std/bool.md#std_bool">bool</a>): <a href="../std/option.md#std_option_Option">Option</a><$T> { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>() && $f(o.<a href="../std/option.md#std_option_borrow">borrow</a>())) o else <a href="../std/option.md#std_option_none">none</a>() } </code></pre> </details>

Macro function `is_some_and`

Return <code>false</code> if the value is <code>None</code>, otherwise return the result of the predicate <code>f</code>.

<pre><code>public macro fun <a href="../std/option.md#std_option_is_some_and">is_some_and</a><$T>($o: &<a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $f: |&$T| -> <a href="../std/bool.md#std_bool">bool</a>): <a href="../std/bool.md#std_bool">bool</a> </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_is_some_and">is_some_and</a><$T>($o: &<a href="../std/option.md#std_option_Option">Option</a><$T>, $f: |&$T| -> <a href="../std/bool.md#std_bool">bool</a>): <a href="../std/bool.md#std_bool">bool</a> { let o = $o; o.<a href="../std/option.md#std_option_is_some">is_some</a>() && $f(o.<a href="../std/option.md#std_option_borrow">borrow</a>()) } </code></pre> </details>

Macro function `extract_or`

Extract the value inside <code><a href="../std/option.md#std_option_Option">Option</a><T></code> if it holds one, or <code>default</code> otherwise. Similar to <code><a href="../std/option.md#std_option_destroy_or">destroy_or</a></code>, but modifying the input <code><a href="../std/option.md#std_option_Option">Option</a></code> via a mutable reference.

<pre><code>public macro fun <a href="../std/option.md#std_option_extract_or">extract_or</a><$T>($o: &mut <a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $default: $T): $T </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_extract_or">extract_or</a><$T>($o: &mut <a href="../std/option.md#std_option_Option">Option</a><$T>, $default: $T): $T { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>()) o.<a href="../std/option.md#std_option_extract">extract</a>() else $default } </code></pre> </details>

Macro function `destroy_or`

Destroy <code><a href="../std/option.md#std_option_Option">Option</a><T></code> and return the value inside if it holds one, or <code>default</code> otherwise. Equivalent to Rust's <code>t.unwrap_or(default)</code>.

Note: this function is a more efficient version of <code><a href="../std/option.md#std_option_destroy_with_default">destroy_with_default</a></code>, as it does not evaluate the default value unless necessary. The <code><a href="../std/option.md#std_option_destroy_with_default">destroy_with_default</a></code> function should be deprecated in favor of this function.

<pre><code>public macro fun <a href="../std/option.md#std_option_destroy_or">destroy_or</a><$T>($o: <a href="../std/option.md#std_option_Option">std::option::Option</a><$T>, $default: $T): $T </code></pre> <details> <summary>Implementation</summary> <pre><code>public macro fun <a href="../std/option.md#std_option_destroy_or">destroy_or</a><$T>($o: <a href="../std/option.md#std_option_Option">Option</a><$T>, $default: $T): $T { let o = $o; if (o.<a href="../std/option.md#std_option_is_some">is_some</a>()) { o.<a href="../std/option.md#std_option_destroy_some">destroy_some</a>() } else { o.<a href="../std/option.md#std_option_destroy_none">destroy_none</a>(); $default } } </code></pre> </details>

Module `std::option`

Module std::option

Struct Option

Constants

Function none

Function some

Function is_none

Function is_some

Function contains

Function borrow

Function borrow_with_default

Function get_with_default

Function fill

Function extract

Function borrow_mut

Function swap

Function swap_or_fill

Function destroy_with_default

Function destroy_some

Function destroy_none

Function to_vec

Macro function destroy

Macro function do

Macro function do_ref

Macro function do_mut

Macro function or

Macro function and

Macro function and_ref

Macro function map

Macro function map_ref

Macro function filter

Macro function is_some_and

Macro function extract_or

Macro function destroy_or

Module `std::option`

Struct `Option`

Function `none`

Function `some`

Function `is_none`

Function `is_some`

Function `contains`

Function `borrow`

Function `borrow_with_default`

Function `get_with_default`

Function `fill`

Function `extract`

Function `borrow_mut`

Function `swap`

Function `swap_or_fill`

Function `destroy_with_default`

Function `destroy_some`

Function `destroy_none`

Function `to_vec`

Macro function `destroy`

Macro function `do`

Macro function `do_ref`

Macro function `do_mut`

Macro function `or`

Macro function `and`

Macro function `and_ref`

Macro function `map`

Macro function `map_ref`

Macro function `filter`

Macro function `is_some_and`

Macro function `extract_or`

Macro function `destroy_or`