Rust: From and Into trait - Part 2

Signed-off-by: Vineel Kovvuri <[email protected]>
vineelkovvuri · Jan 15, 2025 · deb4a32 · deb4a32
1 parent 9b725d1
commit deb4a32
Show file tree

Hide file tree

Showing 51 changed files with 424 additions and 247 deletions.
diff --git a/content/blog/Rust-Aligned-vs-Unaligned-Memory-Access/index.md b/content/blog/Rust-Aligned-vs-Unaligned-Memory-Access/index.md
@@ -4,15 +4,13 @@ date: 2025-01-14 19:05:52
 tags: ['Rust']
 ---
 
-## Rust: Rust-Aligned-vs-Unaligned-Memory-Access
+## Rust: Rust Aligned vs Unaligned Memory Access
 
 Unlike C, Rust enforces some rules when trying to access memory. Mainly it
 requires consideration to alignment of the data that we are trying to read.
 Below code will illustrate the details.
 
 ```rust
-#![allow(unused)]
-
 fn main() {
     let data: [u8; 10] = [0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xAA];
 

diff --git a/content/blog/Rust-From-vs-Into-traits-Part-2/index.md b/content/blog/Rust-From-vs-Into-traits-Part-2/index.md
@@ -0,0 +1,51 @@
+---
+title: "Rust: From and Into trait - Part 2"
+date: 2025-01-14 23:33:54
+tags: ['Rust']
+---
+
+## Rust: From and Into trait usage
+
+Knowing how Rust's `From` and `Into` traits work is one part of the story, but
+being able to use them efficiently is another. In this code sample, we will
+explore how to define functions or methods that accept parameters which can be
+converted from and into the expected types.
+
+In this code, we have two functions, `increment()` and `increment2()`, and we
+will see how they work with the `From` trait implemented for the `Number` type.
+
+```rust
+struct Number(u64);
+
+fn increment(n: Number) -> Number {
+    Number(n.0 + 1)
+}
+
+fn increment2<T>(n: T) -> Number
+where
+    T: Into<Number>,
+{
+    let number = n.into(); // Conversion is done by the method itself
+    Number(number.0 + 1)
+}
+
+impl From<u64> for Number {
+    fn from(value: u64) -> Self {
+        Self(value)
+    }
+}
+
+fn main() {
+    // Just because we have implemented the From<u64> do not make the conversion
+    // from 10 to Number implicit. Below line do not compile.
+    let num = increment(10);
+    // You have to explicitly request the conversion by calling .into()
+    let num = increment(10.into());
+    // Or even better, make the increment2 method accept any type that can be
+    // converted into a Number. Since u64 can be converted into Number (as it
+    // implements From<u64>), increment2() can call the .into() method itself to
+    // perform the conversion. At the call site, we simply pass the u64 as a
+    // parameter.
+    let num = increment2(10);
+}
+```
diff --git a/docs/404.html b/docs/404.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>404 Page not found | Vineel Kovvuri</title>

diff --git a/docs/blog/a-newbies-introduction-to-compilation-process-and-reverse-engineering/index.html b/docs/blog/a-newbies-introduction-to-compilation-process-and-reverse-engineering/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>A Newbie&#39;s Introduction To Compilation Process And Reverse Engineering | Vineel Kovvuri</title>

diff --git a/docs/blog/c-case-studies/f/index.html b/docs/blog/c-case-studies/f/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>Libspng - C Language Case Study | Vineel Kovvuri</title>

diff --git a/docs/blog/compiler-internals/index.html b/docs/blog/compiler-internals/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>Compiler Internals | Vineel Kovvuri</title>

diff --git a/docs/blog/how-do-breakpoints-work-in-debuggers/index.html b/docs/blog/how-do-breakpoints-work-in-debuggers/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>How Do Breakpoints Work In Debuggers? | Vineel Kovvuri</title>

diff --git a/docs/blog/index.html b/docs/blog/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>Blogs | Vineel Kovvuri</title>
@@ -35,6 +35,11 @@ <h1>Blog</h1>
 
 
 
+    <li>
+      <span class="date">2025/01/14</span>
+      <a href="/blog/rust-from-vs-into-traits-part-2/">Rust: From and Into trait - Part 2 - blog</a>
+    </li>
+
     <li>
       <span class="date">2025/01/14</span>
       <a href="/blog/rust-aligned-vs-unaligned-memory-access/">Rust: Aligned vs Unaligned Memory Access - blog</a>

diff --git a/docs/blog/index.xml b/docs/blog/index.xml
diff --git a/docs/blog/lib-files-101/index.html b/docs/blog/lib-files-101/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>Lib Files 101 | Vineel Kovvuri</title>

diff --git a/docs/blog/pci-express-basics-101/index.html b/docs/blog/pci-express-basics-101/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>PCI Express Basics 101 | Vineel Kovvuri</title>

diff --git a/docs/blog/pdb-files-the-glue-between-the-binary-file-and-source-code/index.html b/docs/blog/pdb-files-the-glue-between-the-binary-file-and-source-code/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>Pdb Files: The Glue Between The Binary File And Source Code | Vineel Kovvuri</title>
@@ -287,7 +287,7 @@ <h1 id="windbg-symbols-and-sources-search-heuristics">Windbg Symbols and Sources
 </span></span><span style="display:flex;"><span>00007ff9<span style="color:#d20;background-color:#fff0f0">`</span>2f400000 00007ff9<span style="color:#d20;background-color:#fff0f0">`</span>2f5e0000   ntdll      (<span style="color:#038">export</span> symbols)
 </span></span><span style="display:flex;"><span>C:<span style="color:#04d;background-color:#fff0f0">\W</span>INDOWS<span style="color:#04d;background-color:#fff0f0">\S</span>YSTEM32<span style="color:#04d;background-color:#fff0f0">\n</span>tdll.dll
 </span></span></code></pre></div><p>Looking at the .reload command output we can say Windbg expects symbol files to
-be present inside the same directory as the application or the folder named &rsquo;exe&rsquo;
+be present inside the same directory as the application or the folder named &rsquo;exe'
 inside .sympath directory or the folder named &lsquo;dll&rsquo; inside the .sympath directory
 or at the actual embedded path. Running lm confirms that symbols are recognized
 for Win32Sample.exe</p>

diff --git a/docs/blog/rust-aligned-vs-unaligned-memory-access/index.html b/docs/blog/rust-aligned-vs-unaligned-memory-access/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>Rust: Aligned vs Unaligned Memory Access | Vineel Kovvuri</title>
@@ -33,13 +33,11 @@ <h2 class="date">2025/01/14</h2>
 </div>
 
 <main>
-<h2 id="rust-rust-aligned-vs-unaligned-memory-access">Rust: Rust-Aligned-vs-Unaligned-Memory-Access</h2>
+<h2 id="rust-rust-aligned-vs-unaligned-memory-access">Rust: Rust Aligned vs Unaligned Memory Access</h2>
 <p>Unlike C, Rust enforces some rules when trying to access memory. Mainly it
 requires consideration to alignment of the data that we are trying to read.
 Below code will illustrate the details.</p>
-<div class="highlight"><pre tabindex="0" style="background-color:#fff;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-rust" data-lang="rust"><span style="display:flex;"><span><span style="color:#c00;font-weight:bold">#![allow(unused)]</span><span style="color:#bbb">
-</span></span></span><span style="display:flex;"><span><span style="color:#bbb">
-</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span><span style="color:#080;font-weight:bold">fn</span> <span style="color:#06b;font-weight:bold">main</span>()<span style="color:#bbb"> </span>{<span style="color:#bbb">
+<div class="highlight"><pre tabindex="0" style="background-color:#fff;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-rust" data-lang="rust"><span style="display:flex;"><span><span style="color:#080;font-weight:bold">fn</span> <span style="color:#06b;font-weight:bold">main</span>()<span style="color:#bbb"> </span>{<span style="color:#bbb">
 </span></span></span><span style="display:flex;"><span><span style="color:#bbb">    </span><span style="color:#080;font-weight:bold">let</span><span style="color:#bbb"> </span>data: [<span style="color:#888;font-weight:bold">u8</span>;<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">10</span>]<span style="color:#bbb"> </span>=<span style="color:#bbb"> </span>[<span style="color:#00d;font-weight:bold">0x11</span>,<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">0x22</span>,<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">0x33</span>,<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">0x44</span>,<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">0x55</span>,<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">0x66</span>,<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">0x77</span>,<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">0x88</span>,<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">0x99</span>,<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">0xAA</span>];<span style="color:#bbb">
 </span></span></span><span style="display:flex;"><span><span style="color:#bbb">
 </span></span></span><span style="display:flex;"><span><span style="color:#bbb">    </span><span style="color:#888">// Alignment Tidbit: Alignment depends on the data type we are using. u8 has

diff --git a/docs/blog/rust-from-vs-into-traits-part-2/index.html b/docs/blog/rust-from-vs-into-traits-part-2/index.html
@@ -0,0 +1,96 @@
+<!DOCTYPE html>
+<html lang="en-us">
+  <head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <title>Rust: From and Into trait - Part 2 | Vineel Kovvuri</title>
+    <link rel="stylesheet" href="/css/style.css" />
+    <link rel="stylesheet" href="/css/fonts.css" />
+    <link href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/github.min.css" rel="stylesheet">
+
+  </head>
+
+  <body>
+    <nav>
+    <ul class="menu">
+
+      <li><a href="/">Home</a></li>
+
+      <li><a href="/blog/">Blog</a></li>
+
+      <li><a href="/presentations/">Presentations</a></li>
+
+      <li><a href="/index.xml">Subscribe</a></li>
+
+    </ul>
+    <hr/>
+    </nav>
+
+<div class="article-meta">
+<h1><span class="title">Rust: From and Into trait - Part 2</span></h1>
+
+<h2 class="date">2025/01/14</h2>
+</div>
+
+<main>
+<h2 id="rust-from-and-into-trait-usage">Rust: From and Into trait usage</h2>
+<p>Knowing how Rust&rsquo;s <code>From</code> and <code>Into</code> traits work is one part of the story, but
+being able to use them efficiently is another. In this code sample, we will
+explore how to define functions or methods that accept parameters which can be
+converted from and into the expected types.</p>
+<p>In this code, we have two functions, <code>increment()</code> and <code>increment2()</code>, and we
+will see how they work with the <code>From</code> trait implemented for the <code>Number</code> type.</p>
+<div class="highlight"><pre tabindex="0" style="background-color:#fff;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-rust" data-lang="rust"><span style="display:flex;"><span><span style="color:#080;font-weight:bold">struct</span> <span style="color:#b06;font-weight:bold">Number</span>(<span style="color:#888;font-weight:bold">u64</span>);<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span><span style="color:#080;font-weight:bold">fn</span> <span style="color:#06b;font-weight:bold">increment</span>(n: <span style="color:#b06;font-weight:bold">Number</span>)<span style="color:#bbb"> </span>-&gt; <span style="color:#b06;font-weight:bold">Number</span><span style="color:#bbb"> </span>{<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">    </span>Number(n.<span style="color:#00d;font-weight:bold">0</span><span style="color:#bbb"> </span>+<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">1</span>)<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span>}<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span><span style="color:#080;font-weight:bold">fn</span> <span style="color:#06b;font-weight:bold">increment2</span>&lt;T&gt;(n: <span style="color:#b06;font-weight:bold">T</span>)<span style="color:#bbb"> </span>-&gt; <span style="color:#b06;font-weight:bold">Number</span><span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span><span style="color:#080;font-weight:bold">where</span><span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">    </span>T: <span style="color:#038">Into</span>&lt;Number&gt;,<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span>{<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">    </span><span style="color:#080;font-weight:bold">let</span><span style="color:#bbb"> </span>number<span style="color:#bbb"> </span>=<span style="color:#bbb"> </span>n.into();<span style="color:#bbb"> </span><span style="color:#888">// Conversion is done by the method itself
+</span></span></span><span style="display:flex;"><span><span style="color:#888"></span><span style="color:#bbb">    </span>Number(number.<span style="color:#00d;font-weight:bold">0</span><span style="color:#bbb"> </span>+<span style="color:#bbb"> </span><span style="color:#00d;font-weight:bold">1</span>)<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span>}<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span><span style="color:#080;font-weight:bold">impl</span><span style="color:#bbb"> </span><span style="color:#038">From</span>&lt;<span style="color:#888;font-weight:bold">u64</span>&gt;<span style="color:#bbb"> </span><span style="color:#080;font-weight:bold">for</span><span style="color:#bbb"> </span>Number<span style="color:#bbb"> </span>{<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">    </span><span style="color:#080;font-weight:bold">fn</span> <span style="color:#06b;font-weight:bold">from</span>(value: <span style="color:#888;font-weight:bold">u64</span>)<span style="color:#bbb"> </span>-&gt; <span style="color:#b06;font-weight:bold">Self</span><span style="color:#bbb"> </span>{<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">        </span>Self(value)<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">    </span>}<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span>}<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span><span style="color:#080;font-weight:bold">fn</span> <span style="color:#06b;font-weight:bold">main</span>()<span style="color:#bbb"> </span>{<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">    </span><span style="color:#888">// Just because we have implemented the From&lt;u64&gt; do not make the conversion
+</span></span></span><span style="display:flex;"><span><span style="color:#888"></span><span style="color:#bbb">    </span><span style="color:#888">// from 10 to Number implicit. Below line do not compile.
+</span></span></span><span style="display:flex;"><span><span style="color:#888"></span><span style="color:#bbb">    </span><span style="color:#080;font-weight:bold">let</span><span style="color:#bbb"> </span>num<span style="color:#bbb"> </span>=<span style="color:#bbb"> </span>increment(<span style="color:#00d;font-weight:bold">10</span>);<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">    </span><span style="color:#888">// You have to explicitly request the conversion by calling .into()
+</span></span></span><span style="display:flex;"><span><span style="color:#888"></span><span style="color:#bbb">    </span><span style="color:#080;font-weight:bold">let</span><span style="color:#bbb"> </span>num<span style="color:#bbb"> </span>=<span style="color:#bbb"> </span>increment(<span style="color:#00d;font-weight:bold">10.</span>into());<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb">    </span><span style="color:#888">// Or even better, make the increment2 method accept any type that can be
+</span></span></span><span style="display:flex;"><span><span style="color:#888"></span><span style="color:#bbb">    </span><span style="color:#888">// converted into a Number. Since u64 can be converted into Number (as it
+</span></span></span><span style="display:flex;"><span><span style="color:#888"></span><span style="color:#bbb">    </span><span style="color:#888">// implements From&lt;u64&gt;), increment2() can call the .into() method itself to
+</span></span></span><span style="display:flex;"><span><span style="color:#888"></span><span style="color:#bbb">    </span><span style="color:#888">// perform the conversion. At the call site, we simply pass the u64 as a
+</span></span></span><span style="display:flex;"><span><span style="color:#888"></span><span style="color:#bbb">    </span><span style="color:#888">// parameter.
+</span></span></span><span style="display:flex;"><span><span style="color:#888"></span><span style="color:#bbb">    </span><span style="color:#080;font-weight:bold">let</span><span style="color:#bbb"> </span>num<span style="color:#bbb"> </span>=<span style="color:#bbb"> </span>increment2(<span style="color:#00d;font-weight:bold">10</span>);<span style="color:#bbb">
+</span></span></span><span style="display:flex;"><span><span style="color:#bbb"></span>}<span style="color:#bbb">
+</span></span></span></code></pre></div>
+</main>
+
+  <footer>
+
+<script defer src="/js/center-img.js"></script>
+
+
+
+
+
+
+
+
+  <hr/>
+  © Vineel Kumar Reddy Kovvuri 2017 &ndash; 2025 ❤️ <a href="https://xmin.yihui.org/">Hugo Xmin</a>
+
+  </footer>
+  </body>
+</html>
+
diff --git a/docs/blog/rust-from-vs-into-traits/index.html b/docs/blog/rust-from-vs-into-traits/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>Rust: From vs Into traits | Vineel Kovvuri</title>

diff --git a/docs/blog/rust-sharing-objects/index.html b/docs/blog/rust-sharing-objects/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html lang="en-us">
-  <head><script src="/livereload.js?mindelay=10&amp;v=2&amp;port=9999&amp;path=livereload" data-no-instant defer></script>
+  <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>Rust: Sharing a Single Object Across Multiple Owners | Vineel Kovvuri</title>