1 <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Trait describing an integer type which can be used as a “packed” sequence of Fe32s."><title>PackedFe32 in bdk_chain::bitcoin::bech32::primitives::checksum - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../../../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../../../../static.files/rustdoc-46132b98.css"><meta name="rustdoc-vars" data-root-path="../../../../../" data-static-root-path="../../../../../static.files/" data-current-crate="bdk_chain" data-themes="" data-resource-suffix="" data-rustdoc-version="1.86.0-nightly (824759493 2025-01-09)" data-channel="nightly" data-search-js="search-75f5ac3e.js" data-settings-js="settings-0f613d39.js" ><script src="../../../../../static.files/storage-59e33391.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../../../../static.files/main-5f194d8c.js"></script><noscript><link rel="stylesheet" href="../../../../../static.files/noscript-893ab5e7.css"></noscript><link rel="alternate icon" type="image/png" href="../../../../../static.files/favicon-32x32-6580c154.png"><link rel="icon" type="image/svg+xml" href="../../../../../static.files/favicon-044be391.svg"></head><body class="rustdoc trait"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button><a class="logo-container" href="../../../../../bdk_chain/index.html"><img src="https://github.com/bitcoindevkit/bdk/raw/master/static/bdk.png" alt=""></a></nav><nav class="sidebar"><div class="sidebar-crate"><a class="logo-container" href="../../../../../bdk_chain/index.html"><img src="https://github.com/bitcoindevkit/bdk/raw/master/static/bdk.png" alt="logo"></a><h2><a href="../../../../../bdk_chain/index.html">bdk_<wbr>chain</a><span class="version">0.21.1</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">Packed<wbr>Fe32</a></h2><h3><a href="#required-associated-consts">Required Associated Constants</a></h3><ul class="block"><li><a href="#associatedconstant.ONE" title="ONE">ONE</a></li></ul><h3><a href="#provided-associated-consts">Provided Associated Constants</a></h3><ul class="block"><li><a href="#associatedconstant.WIDTH" title="WIDTH">WIDTH</a></li></ul><h3><a href="#required-methods">Required Methods</a></h3><ul class="block"><li><a href="#tymethod.mul_by_x_then_add" title="mul_by_x_then_add">mul_by_x_then_add</a></li><li><a href="#tymethod.unpack" title="unpack">unpack</a></li></ul><h3><a href="#foreign-impls">Implementations on Foreign Types</a></h3><ul class="block"><li><a href="#impl-PackedFe32-for-u128" title="u128">u128</a></li><li><a href="#impl-PackedFe32-for-u32" title="u32">u32</a></li><li><a href="#impl-PackedFe32-for-u64" title="u64">u64</a></li></ul><h3><a href="#dyn-compatibility">Dyn Compatibility</a></h3><h3><a href="#implementors">Implementors</a></h3></section><div id="rustdoc-modnav"><h2><a href="index.html">In bdk_<wbr>chain::<wbr>bitcoin::<wbr>bech32::<wbr>primitives::<wbr>checksum</a></h2></div></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><span class="rustdoc-breadcrumbs"><a href="../../../../index.html">bdk_chain</a>::<wbr><a href="../../../index.html">bitcoin</a>::<wbr><a href="../../index.html">bech32</a>::<wbr><a href="../index.html">primitives</a>::<wbr><a href="index.html">checksum</a></span><h1>Trait <span class="trait">PackedFe32</span><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"></span></div><pre class="rust item-decl"><code>pub trait PackedFe32:
2 <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Copy.html" title="trait core::marker::Copy">Copy</a>
3 + <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialEq.html" title="trait core::cmp::PartialEq">PartialEq</a>
4 + <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.Eq.html" title="trait core::cmp::Eq">Eq</a>
5 + <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/bit/trait.BitXor.html" title="trait core::ops::bit::BitXor">BitXor</a><Output = Self> {
6 const <a href="#associatedconstant.ONE" class="constant">ONE</a>: Self;
7 const <a href="#associatedconstant.WIDTH" class="constant">WIDTH</a>: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a> = _;
10 fn <a href="#tymethod.unpack" class="fn">unpack</a>(&self, n: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a>;
11 <span class="item-spacer"></span> fn <a href="#tymethod.mul_by_x_then_add" class="fn">mul_by_x_then_add</a>(&mut self, degree: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>, add: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a>;
12 }</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Trait describing an integer type which can be used as a “packed” sequence of Fe32s.</p>
13 <p>This is implemented for u32, u64 and u128, as a way to treat these primitive types as
14 packed coefficients of polynomials over GF32 (up to some maximal degree, of course).</p>
15 <p>This is useful because then multiplication by x reduces to simply left-shifting by 5,
16 and addition of entire polynomials can be done by xor.</p>
17 </div></details><h2 id="required-associated-consts" class="section-header">Required Associated Constants<a href="#required-associated-consts" class="anchor">§</a></h2><div class="methods"><details class="toggle" open><summary><section id="associatedconstant.ONE" class="method"><h4 class="code-header">const <a href="#associatedconstant.ONE" class="constant">ONE</a>: Self</h4></section></summary><div class="docblock"><p>The one constant, for which stdlib provides no existing trait.</p>
18 </div></details></div><h2 id="provided-associated-consts" class="section-header">Provided Associated Constants<a href="#provided-associated-consts" class="anchor">§</a></h2><div class="methods"><details class="toggle" open><summary><section id="associatedconstant.WIDTH" class="method"><h4 class="code-header">const <a href="#associatedconstant.WIDTH" class="constant">WIDTH</a>: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a> = _</h4></section></summary><div class="docblock"><p>The number of fe32s that can fit into the type; computed as floor(bitwidth / 5).</p>
19 </div></details></div><h2 id="required-methods" class="section-header">Required Methods<a href="#required-methods" class="anchor">§</a></h2><div class="methods"><details class="toggle method-toggle" open><summary><section id="tymethod.unpack" class="method"><h4 class="code-header">fn <a href="#tymethod.unpack" class="fn">unpack</a>(&self, n: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a></h4></section></summary><div class="docblock"><p>Extracts the coefficient of the x^n from the packed polynomial.</p>
20 </div></details><details class="toggle method-toggle" open><summary><section id="tymethod.mul_by_x_then_add" class="method"><h4 class="code-header">fn <a href="#tymethod.mul_by_x_then_add" class="fn">mul_by_x_then_add</a>(&mut self, degree: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>, add: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a></h4></section></summary><div class="docblock"><p>Multiply the polynomial by x, drop its highest coefficient (and return it), and
21 add a new field element to the now-0 constant coefficient.</p>
22 <p>Takes the degree of the polynomial as an input; for checksum applications
23 this should basically always be <code>Checksum::CHECKSUM_WIDTH</code>.</p>
24 </div></details></div><h2 id="dyn-compatibility" class="section-header">Dyn Compatibility<a href="#dyn-compatibility" class="anchor">§</a></h2><div class="dyn-compatibility-info"><p>This trait is <b>not</b> <a href="https://doc.rust-lang.org/nightly/reference/items/traits.html#object-safety">dyn compatible</a>.</p><p><i>In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.</i></p></div><h2 id="foreign-impls" class="section-header">Implementations on Foreign Types<a href="#foreign-impls" class="anchor">§</a></h2><details class="toggle implementors-toggle"><summary><section id="impl-PackedFe32-for-u32" class="impl"><a href="#impl-PackedFe32-for-u32" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="trait.PackedFe32.html" title="trait bdk_chain::bitcoin::bech32::primitives::checksum::PackedFe32">PackedFe32</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u32.html">u32</a></h3></section></summary><div class="impl-items"><section id="associatedconstant.ONE-1" class="associatedconstant trait-impl"><a href="#associatedconstant.ONE-1" class="anchor">§</a><h4 class="code-header">const <a href="#associatedconstant.ONE" class="constant">ONE</a>: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u32.html">u32</a> = 1u32</h4></section><section id="method.unpack" class="method trait-impl"><a href="#method.unpack" class="anchor">§</a><h4 class="code-header">fn <a href="#tymethod.unpack" class="fn">unpack</a>(&self, n: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a></h4></section><section id="method.mul_by_x_then_add" class="method trait-impl"><a href="#method.mul_by_x_then_add" class="anchor">§</a><h4 class="code-header">fn <a href="#tymethod.mul_by_x_then_add" class="fn">mul_by_x_then_add</a>(&mut self, degree: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>, add: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a></h4></section></div></details><details class="toggle implementors-toggle"><summary><section id="impl-PackedFe32-for-u64" class="impl"><a href="#impl-PackedFe32-for-u64" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="trait.PackedFe32.html" title="trait bdk_chain::bitcoin::bech32::primitives::checksum::PackedFe32">PackedFe32</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u64.html">u64</a></h3></section></summary><div class="impl-items"><section id="associatedconstant.ONE-2" class="associatedconstant trait-impl"><a href="#associatedconstant.ONE-2" class="anchor">§</a><h4 class="code-header">const <a href="#associatedconstant.ONE" class="constant">ONE</a>: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u64.html">u64</a> = 1u64</h4></section><section id="method.unpack-1" class="method trait-impl"><a href="#method.unpack-1" class="anchor">§</a><h4 class="code-header">fn <a href="#tymethod.unpack" class="fn">unpack</a>(&self, n: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a></h4></section><section id="method.mul_by_x_then_add-1" class="method trait-impl"><a href="#method.mul_by_x_then_add-1" class="anchor">§</a><h4 class="code-header">fn <a href="#tymethod.mul_by_x_then_add" class="fn">mul_by_x_then_add</a>(&mut self, degree: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>, add: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a></h4></section></div></details><details class="toggle implementors-toggle"><summary><section id="impl-PackedFe32-for-u128" class="impl"><a href="#impl-PackedFe32-for-u128" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="trait.PackedFe32.html" title="trait bdk_chain::bitcoin::bech32::primitives::checksum::PackedFe32">PackedFe32</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u128.html">u128</a></h3></section></summary><div class="impl-items"><section id="associatedconstant.ONE-3" class="associatedconstant trait-impl"><a href="#associatedconstant.ONE-3" class="anchor">§</a><h4 class="code-header">const <a href="#associatedconstant.ONE" class="constant">ONE</a>: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u128.html">u128</a> = 1u128</h4></section><section id="method.unpack-2" class="method trait-impl"><a href="#method.unpack-2" class="anchor">§</a><h4 class="code-header">fn <a href="#tymethod.unpack" class="fn">unpack</a>(&self, n: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a></h4></section><section id="method.mul_by_x_then_add-2" class="method trait-impl"><a href="#method.mul_by_x_then_add-2" class="anchor">§</a><h4 class="code-header">fn <a href="#tymethod.mul_by_x_then_add" class="fn">mul_by_x_then_add</a>(&mut self, degree: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>, add: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a></h4></section></div></details><h2 id="implementors" class="section-header">Implementors<a href="#implementors" class="anchor">§</a></h2><div id="implementors-list"><details class="toggle implementors-toggle"><summary><section id="impl-PackedFe32-for-PackedNull" class="impl"><a href="#impl-PackedFe32-for-PackedNull" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="trait.PackedFe32.html" title="trait bdk_chain::bitcoin::bech32::primitives::checksum::PackedFe32">PackedFe32</a> for <a class="struct" href="struct.PackedNull.html" title="struct bdk_chain::bitcoin::bech32::primitives::checksum::PackedNull">PackedNull</a></h3></section></summary><div class="impl-items"><section id="associatedconstant.ONE-4" class="associatedconstant trait-impl"><a href="#associatedconstant.ONE-4" class="anchor">§</a><h4 class="code-header">const <a href="#associatedconstant.ONE" class="constant">ONE</a>: <a class="struct" href="struct.PackedNull.html" title="struct bdk_chain::bitcoin::bech32::primitives::checksum::PackedNull">PackedNull</a> = PackedNull</h4></section></div></details></div><script src="../../../../../trait.impl/bech32/primitives/checksum/trait.PackedFe32.js" data-ignore-extern-crates="bech32,std" async></script></section></div></main></body></html>
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