feedc0de/mp-units
1
0
Fork 0
forked from mpusz/mp-units
Code Pull Requests Activity
Files
5092f01adb21dba94de76b708e55582c10f2eac4
mp-units/2.2/getting_started/quick_start/index.html
T
Mateusz Pusz 32808bef78 Reinit docs to shrink git repo
2024-11-05 18:52:17 +01:00

2468 lines
84 KiB
HTML
Raw Blame History

<!doctype html>
<html lang="en" class="no-js">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<meta name="description" content="The quantities and units library for C++">
<meta name="author" content="mp-units Team">
<link rel="canonical" href="https://mpusz.github.io/mp-units/2.2/getting_started/quick_start/">
<link rel="prev" href="../introduction/">
<link rel="next" href="../look_and_feel/">
<link rel="alternate" type="application/rss+xml" title="RSS feed" href="../../feed_rss_created.xml">
<link rel="alternate" type="application/rss+xml" title="RSS feed of updated content" href="../../feed_rss_updated.xml">
<link rel="icon" href="../../assets/images/mp-units-color.svg">
<meta name="generator" content="mkdocs-1.6.0, mkdocs-material-9.5.26">
<title>Quick Start - mp-units</title>
<link rel="stylesheet" href="../../assets/stylesheets/main.6543a935.min.css">
<link rel="stylesheet" href="../../assets/stylesheets/palette.06af60db.min.css">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,300i,400,400i,700,700i%7CRoboto+Mono:400,400i,700,700i&display=fallback">
<style>:root{--md-text-font:"Roboto";--md-code-font:"Roboto Mono"}</style>
<link rel="stylesheet" href="../../stylesheets/extra.css">
<script>__md_scope=new URL("../..",location),__md_hash=e=>[...e].reduce((e,_)=>(e<<5)-e+_.charCodeAt(0),0),__md_get=(e,_=localStorage,t=__md_scope)=>JSON.parse(_.getItem(t.pathname+"."+e)),__md_set=(e,_,t=localStorage,a=__md_scope)=>{try{t.setItem(a.pathname+"."+e,JSON.stringify(_))}catch(e){}}</script>
<meta property="og:type" content="website" >
<meta property="og:title" content="Quick Start - mp-units" >
<meta property="og:description" content="The quantities and units library for C++" >
<meta property="og:image" content="https://mpusz.github.io/mp-units/2.2/assets/images/social/getting_started/quick_start.png" >
<meta property="og:image:type" content="image/png" >
<meta property="og:image:width" content="1200" >
<meta property="og:image:height" content="630" >
<meta property="og:url" content="https://mpusz.github.io/mp-units/2.2/getting_started/quick_start/" >
<meta name="twitter:card" content="summary_large_image" >
<meta name="twitter:title" content="Quick Start - mp-units" >
<meta name="twitter:description" content="The quantities and units library for C++" >
<meta name="twitter:image" content="https://mpusz.github.io/mp-units/2.2/assets/images/social/getting_started/quick_start.png" >
</head>
<body dir="ltr" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="indigo">
<input class="md-toggle" data-md-toggle="drawer" type="checkbox" id="__drawer" autocomplete="off">
<input class="md-toggle" data-md-toggle="search" type="checkbox" id="__search" autocomplete="off">
<label class="md-overlay" for="__drawer"></label>
<div data-md-component="skip">
<a href="#quick-start" class="md-skip">
Skip to content
</a>
</div>
<div data-md-component="announce">
</div>
<div data-md-color-scheme="default" data-md-component="outdated" hidden>
<aside class="md-banner md-banner--warning">
<div class="md-banner__inner md-grid md-typeset">
You're not viewing the latest version.
<a href="../../..">
<strong>Click here to go to latest.</strong>
</a>
</div>
<script>var el=document.querySelector("[data-md-component=outdated]"),outdated=__md_get("__outdated",sessionStorage);!0===outdated&&el&&(el.hidden=!1)</script>
</aside>
</div>
<header class="md-header" data-md-component="header">
<nav class="md-header__inner md-grid" aria-label="Header">
<a href="../.." title="mp-units" class="md-header__button md-logo" aria-label="mp-units" data-md-component="logo">
<img src="../../assets/images/mp-units-transparent-white.svg" alt="logo">
</a>
<label class="md-header__button md-icon" for="__drawer">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3 6h18v2H3V6m0 5h18v2H3v-2m0 5h18v2H3v-2Z"/></svg>
</label>
<div class="md-header__title" data-md-component="header-title">
<div class="md-header__ellipsis">
<div class="md-header__topic">
<span class="md-ellipsis">
mp-units
</span>
</div>
<div class="md-header__topic" data-md-component="header-topic">
<span class="md-ellipsis">
Quick Start
</span>
</div>
</div>
</div>
<form class="md-header__option" data-md-component="palette">
<input class="md-option" data-md-color-media="(prefers-color-scheme)" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="indigo" aria-label="Switch to light mode" type="radio" name="__palette" id="__palette_0">
<label class="md-header__button md-icon" title="Switch to light mode" for="__palette_1" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3.9 12c0-1.71 1.39-3.1 3.1-3.1h4V7H7a5 5 0 0 0-5 5 5 5 0 0 0 5 5h4v-1.9H7c-1.71 0-3.1-1.39-3.1-3.1M8 13h8v-2H8v2m9-6h-4v1.9h4c1.71 0 3.1 1.39 3.1 3.1 0 1.71-1.39 3.1-3.1 3.1h-4V17h4a5 5 0 0 0 5-5 5 5 0 0 0-5-5Z"/></svg>
</label>
<input class="md-option" data-md-color-media="(prefers-color-scheme: light)" data-md-color-scheme="default" data-md-color-primary="custom" data-md-color-accent="custom" aria-label="Switch to dark mode" type="radio" name="__palette" id="__palette_1">
<label class="md-header__button md-icon" title="Switch to dark mode" for="__palette_2" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 7a5 5 0 0 1 5 5 5 5 0 0 1-5 5 5 5 0 0 1-5-5 5 5 0 0 1 5-5m0 2a3 3 0 0 0-3 3 3 3 0 0 0 3 3 3 3 0 0 0 3-3 3 3 0 0 0-3-3m0-7 2.39 3.42C13.65 5.15 12.84 5 12 5c-.84 0-1.65.15-2.39.42L12 2M3.34 7l4.16-.35A7.2 7.2 0 0 0 5.94 8.5c-.44.74-.69 1.5-.83 2.29L3.34 7m.02 10 1.76-3.77a7.131 7.131 0 0 0 2.38 4.14L3.36 17M20.65 7l-1.77 3.79a7.023 7.023 0 0 0-2.38-4.15l4.15.36m-.01 10-4.14.36c.59-.51 1.12-1.14 1.54-1.86.42-.73.69-1.5.83-2.29L20.64 17M12 22l-2.41-3.44c.74.27 1.55.44 2.41.44.82 0 1.63-.17 2.37-.44L12 22Z"/></svg>
</label>
<input class="md-option" data-md-color-media="(prefers-color-scheme: dark)" data-md-color-scheme="slate" data-md-color-primary="black" data-md-color-accent="custom" aria-label="Switch to system preference" type="radio" name="__palette" id="__palette_2">
<label class="md-header__button md-icon" title="Switch to system preference" for="__palette_0" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="m17.75 4.09-2.53 1.94.91 3.06-2.63-1.81-2.63 1.81.91-3.06-2.53-1.94L12.44 4l1.06-3 1.06 3 3.19.09m3.5 6.91-1.64 1.25.59 1.98-1.7-1.17-1.7 1.17.59-1.98L15.75 11l2.06-.05L18.5 9l.69 1.95 2.06.05m-2.28 4.95c.83-.08 1.72 1.1 1.19 1.85-.32.45-.66.87-1.08 1.27C15.17 23 8.84 23 4.94 19.07c-3.91-3.9-3.91-10.24 0-14.14.4-.4.82-.76 1.27-1.08.75-.53 1.93.36 1.85 1.19-.27 2.86.69 5.83 2.89 8.02a9.96 9.96 0 0 0 8.02 2.89m-1.64 2.02a12.08 12.08 0 0 1-7.8-3.47c-2.17-2.19-3.33-5-3.49-7.82-2.81 3.14-2.7 7.96.31 10.98 3.02 3.01 7.84 3.12 10.98.31Z"/></svg>
</label>
</form>
<script>var media,input,key,value,palette=__md_get("__palette");if(palette&&palette.color){"(prefers-color-scheme)"===palette.color.media&&(media=matchMedia("(prefers-color-scheme: light)"),input=document.querySelector(media.matches?"[data-md-color-media='(prefers-color-scheme: light)']":"[data-md-color-media='(prefers-color-scheme: dark)']"),palette.color.media=input.getAttribute("data-md-color-media"),palette.color.scheme=input.getAttribute("data-md-color-scheme"),palette.color.primary=input.getAttribute("data-md-color-primary"),palette.color.accent=input.getAttribute("data-md-color-accent"));for([key,value]of Object.entries(palette.color))document.body.setAttribute("data-md-color-"+key,value)}</script>
<label class="md-header__button md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5Z"/></svg>
</label>
<div class="md-search" data-md-component="search" role="dialog">
<label class="md-search__overlay" for="__search"></label>
<div class="md-search__inner" role="search">
<form class="md-search__form" name="search">
<input type="text" class="md-search__input" name="query" aria-label="Search" placeholder="Search" autocapitalize="off" autocorrect="off" autocomplete="off" spellcheck="false" data-md-component="search-query" required>
<label class="md-search__icon md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5Z"/></svg>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</label>
<nav class="md-search__options" aria-label="Search">
<a href="javascript:void(0)" class="md-search__icon md-icon" title="Share" aria-label="Share" data-clipboard data-clipboard-text="" data-md-component="search-share" tabindex="-1">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M18 16.08c-.76 0-1.44.3-1.96.77L8.91 12.7c.05-.23.09-.46.09-.7 0-.24-.04-.47-.09-.7l7.05-4.11c.54.5 1.25.81 2.04.81a3 3 0 0 0 3-3 3 3 0 0 0-3-3 3 3 0 0 0-3 3c0 .24.04.47.09.7L8.04 9.81C7.5 9.31 6.79 9 6 9a3 3 0 0 0-3 3 3 3 0 0 0 3 3c.79 0 1.5-.31 2.04-.81l7.12 4.15c-.05.21-.08.43-.08.66 0 1.61 1.31 2.91 2.92 2.91 1.61 0 2.92-1.3 2.92-2.91A2.92 2.92 0 0 0 18 16.08Z"/></svg>
</a>
<button type="reset" class="md-search__icon md-icon" title="Clear" aria-label="Clear" tabindex="-1">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19 6.41 17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12 19 6.41Z"/></svg>
</button>
</nav>
<div class="md-search__suggest" data-md-component="search-suggest"></div>
</form>
<div class="md-search__output">
<div class="md-search__scrollwrap" tabindex="0" data-md-scrollfix>
<div class="md-search-result" data-md-component="search-result">
<div class="md-search-result__meta">
Initializing search
</div>
<ol class="md-search-result__list" role="presentation"></ol>
</div>
</div>
</div>
</div>
</div>
<div class="md-header__source">
<a href="https://github.com/mpusz/mp-units" title="Go to repository" class="md-source" data-md-component="source">
<div class="md-source__icon md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><!--! Font Awesome Free 6.5.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2024 Fonticons, Inc.--><path d="M439.55 236.05 244 40.45a28.87 28.87 0 0 0-40.81 0l-40.66 40.63 51.52 51.52c27.06-9.14 52.68 16.77 43.39 43.68l49.66 49.66c34.23-11.8 61.18 31 35.47 56.69-26.49 26.49-70.21-2.87-56-37.34L240.22 199v121.85c25.3 12.54 22.26 41.85 9.08 55a34.34 34.34 0 0 1-48.55 0c-17.57-17.6-11.07-46.91 11.25-56v-123c-20.8-8.51-24.6-30.74-18.64-45L142.57 101 8.45 235.14a28.86 28.86 0 0 0 0 40.81l195.61 195.6a28.86 28.86 0 0 0 40.8 0l194.69-194.69a28.86 28.86 0 0 0 0-40.81z"/></svg>
</div>
<div class="md-source__repository">
mpusz/mp-units
</div>
</a>
</div>
</nav>
</header>
<div class="md-container" data-md-component="container">
<nav class="md-tabs" aria-label="Tabs" data-md-component="tabs">
<div class="md-grid">
<ul class="md-tabs__list">
<li class="md-tabs__item">
<a href="../.." class="md-tabs__link">
Home
</a>
</li>
<li class="md-tabs__item md-tabs__item--active">
<a href="../introduction/" class="md-tabs__link">
Getting Started
</a>
</li>
<li class="md-tabs__item">
<a href="../../users_guide/terms_and_definitions/" class="md-tabs__link">
User's Guide
</a>
</li>
<li class="md-tabs__item">
<a href="../../blog/" class="md-tabs__link">
Blog
</a>
</li>
<li class="md-tabs__item">
<a href="../../release_notes/" class="md-tabs__link">
Release Notes
</a>
</li>
</ul>
</div>
</nav>
<main class="md-main" data-md-component="main">
<div class="md-main__inner md-grid">
<div class="md-sidebar md-sidebar--primary" data-md-component="sidebar" data-md-type="navigation" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--primary md-nav--lifted md-nav--integrated" aria-label="Navigation" data-md-level="0">
<label class="md-nav__title" for="__drawer">
<a href="../.." title="mp-units" class="md-nav__button md-logo" aria-label="mp-units" data-md-component="logo">
<img src="../../assets/images/mp-units-transparent-white.svg" alt="logo">
</a>
mp-units
</label>
<div class="md-nav__source">
<a href="https://github.com/mpusz/mp-units" title="Go to repository" class="md-source" data-md-component="source">
<div class="md-source__icon md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><!--! Font Awesome Free 6.5.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2024 Fonticons, Inc.--><path d="M439.55 236.05 244 40.45a28.87 28.87 0 0 0-40.81 0l-40.66 40.63 51.52 51.52c27.06-9.14 52.68 16.77 43.39 43.68l49.66 49.66c34.23-11.8 61.18 31 35.47 56.69-26.49 26.49-70.21-2.87-56-37.34L240.22 199v121.85c25.3 12.54 22.26 41.85 9.08 55a34.34 34.34 0 0 1-48.55 0c-17.57-17.6-11.07-46.91 11.25-56v-123c-20.8-8.51-24.6-30.74-18.64-45L142.57 101 8.45 235.14a28.86 28.86 0 0 0 0 40.81l195.61 195.6a28.86 28.86 0 0 0 40.8 0l194.69-194.69a28.86 28.86 0 0 0 0-40.81z"/></svg>
</div>
<div class="md-source__repository">
mpusz/mp-units
</div>
</a>
</div>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../.." class="md-nav__link">
<span class="md-ellipsis">
Home
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--active md-nav__item--section md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_2" checked>
<label class="md-nav__link" for="__nav_2" id="__nav_2_label" tabindex="">
<span class="md-ellipsis">
Getting Started
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_2_label" aria-expanded="true">
<label class="md-nav__title" for="__nav_2">
<span class="md-nav__icon md-icon"></span>
Getting Started
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../introduction/" class="md-nav__link">
<span class="md-ellipsis">
Introduction
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--active">
<input class="md-nav__toggle md-toggle" type="checkbox" id="__toc">
<label class="md-nav__link md-nav__link--active" for="__toc">
<span class="md-ellipsis">
Quick Start
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<a href="./" class="md-nav__link md-nav__link--active">
<span class="md-ellipsis">
Quick Start
</span>
</a>
<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
<label class="md-nav__title" for="__toc">
<span class="md-nav__icon md-icon"></span>
Table of contents
</label>
<ul class="md-nav__list" data-md-component="toc" data-md-scrollfix>
<li class="md-nav__item">
<a href="#quantities" class="md-nav__link">
<span class="md-ellipsis">
Quantities
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#quantity-points" class="md-nav__link">
<span class="md-ellipsis">
Quantity points
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../look_and_feel/" class="md-nav__link">
<span class="md-ellipsis">
Look and Feel
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../cpp_compiler_support/" class="md-nav__link">
<span class="md-ellipsis">
C++ compiler support (API/ABI)
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../installation_and_usage/" class="md-nav__link">
<span class="md-ellipsis">
Installation and Usage
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../faq/" class="md-nav__link">
<span class="md-ellipsis">
FAQ
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_3" >
<label class="md-nav__link" for="__nav_3" id="__nav_3_label" tabindex="0">
<span class="md-ellipsis">
User's Guide
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_3_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_3">
<span class="md-nav__icon md-icon"></span>
User's Guide
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../users_guide/terms_and_definitions/" class="md-nav__link">
<span class="md-ellipsis">
Terms and Definitions
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_3_2" >
<label class="md-nav__link" for="__nav_3_2" id="__nav_3_2_label" tabindex="0">
<span class="md-ellipsis">
Framework Basics
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="2" aria-labelledby="__nav_3_2_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_3_2">
<span class="md-nav__icon md-icon"></span>
Framework Basics
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/interface_introduction/" class="md-nav__link">
<span class="md-ellipsis">
Interface Introduction
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/design_overview/" class="md-nav__link">
<span class="md-ellipsis">
Design Overview
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/systems_of_quantities/" class="md-nav__link">
<span class="md-ellipsis">
Systems of Quantities
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/systems_of_units/" class="md-nav__link">
<span class="md-ellipsis">
Systems of Units
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/simple_and_typed_quantities/" class="md-nav__link">
<span class="md-ellipsis">
Simple and Typed Quantities
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/value_conversions/" class="md-nav__link">
<span class="md-ellipsis">
Value Conversions
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/character_of_a_quantity/" class="md-nav__link">
<span class="md-ellipsis">
Character of a Quantity
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/dimensionless_quantities/" class="md-nav__link">
<span class="md-ellipsis">
Dimensionless Quantities
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/quantity_arithmetics/" class="md-nav__link">
<span class="md-ellipsis">
Quantity Arithmetics
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/generic_interfaces/" class="md-nav__link">
<span class="md-ellipsis">
Generic Interfaces
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/faster_than_lightspeed_constants/" class="md-nav__link">
<span class="md-ellipsis">
Faster-than-lightspeed Constants
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/the_affine_space/" class="md-nav__link">
<span class="md-ellipsis">
The Affine Space
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/obtaining_metadata/" class="md-nav__link">
<span class="md-ellipsis">
Obtaining Metadata
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/concepts/" class="md-nav__link">
<span class="md-ellipsis">
Concepts
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/framework_basics/text_output/" class="md-nav__link">
<span class="md-ellipsis">
Text Output
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_3_3" >
<label class="md-nav__link" for="__nav_3_3" id="__nav_3_3_label" tabindex="0">
<span class="md-ellipsis">
Defining Systems
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="2" aria-labelledby="__nav_3_3_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_3_3">
<span class="md-nav__icon md-icon"></span>
Defining Systems
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../users_guide/defining_systems/introduction/" class="md-nav__link">
<span class="md-ellipsis">
Introduction
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/defining_systems/isq/" class="md-nav__link">
<span class="md-ellipsis">
International System of Quantities (ISQ)
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/defining_systems/si/" class="md-nav__link">
<span class="md-ellipsis">
International System of Units (SI)
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/defining_systems/strong_angular_system/" class="md-nav__link">
<span class="md-ellipsis">
Strong Angular System
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/defining_systems/natural_units/" class="md-nav__link">
<span class="md-ellipsis">
Natural Units
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_3_4" >
<label class="md-nav__link" for="__nav_3_4" id="__nav_3_4_label" tabindex="0">
<span class="md-ellipsis">
Use Cases
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="2" aria-labelledby="__nav_3_4_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_3_4">
<span class="md-nav__icon md-icon"></span>
Use Cases
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../users_guide/use_cases/pure_dimensional_analysis/" class="md-nav__link">
<span class="md-ellipsis">
Pure Dimensional Analysis
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/use_cases/working_with_legacy_interfaces/" class="md-nav__link">
<span class="md-ellipsis">
Working with Legacy Interfaces
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/use_cases/using_custom_representation_types/" class="md-nav__link">
<span class="md-ellipsis">
Using Custom Representation Types
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/use_cases/interoperability_with_other_libraries/" class="md-nav__link">
<span class="md-ellipsis">
Interoperability with Other Libraries
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/use_cases/extending_the_library/" class="md-nav__link">
<span class="md-ellipsis">
Extending the Library
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/use_cases/wide_compatibility/" class="md-nav__link">
<span class="md-ellipsis">
Wide Compatibility
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_3_5" >
<label class="md-nav__link" for="__nav_3_5" id="__nav_3_5_label" tabindex="0">
<span class="md-ellipsis">
Examples
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="2" aria-labelledby="__nav_3_5_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_3_5">
<span class="md-nav__icon md-icon"></span>
Examples
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../users_guide/examples/tags_index/" class="md-nav__link">
<span class="md-ellipsis">
Tags Index
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_3_5_2" >
<label class="md-nav__link" for="__nav_3_5_2" id="__nav_3_5_2_label" tabindex="0">
<span class="md-ellipsis">
All Examples
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="3" aria-labelledby="__nav_3_5_2_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_3_5_2">
<span class="md-nav__icon md-icon"></span>
All Examples
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../users_guide/examples/hello_units/" class="md-nav__link">
<span class="md-ellipsis">
hello_units
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/examples/avg_speed/" class="md-nav__link">
<span class="md-ellipsis">
avg_speed
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../users_guide/examples/si_constants/" class="md-nav__link">
<span class="md-ellipsis">
si_constants
</span>
</a>
</li>
</ul>
</nav>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_3_6" >
<label class="md-nav__link" for="__nav_3_6" id="__nav_3_6_label" tabindex="0">
<span class="md-ellipsis">
Appendix
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="2" aria-labelledby="__nav_3_6_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_3_6">
<span class="md-nav__icon md-icon"></span>
Appendix
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../appendix/glossary/" class="md-nav__link">
<span class="md-ellipsis">
Glossary
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../appendix/references/" class="md-nav__link">
<span class="md-ellipsis">
References
</span>
</a>
</li>
</ul>
</nav>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_4" >
<div class="md-nav__link md-nav__container">
<a href="../../blog/" class="md-nav__link ">
<span class="md-ellipsis">
Blog
</span>
</a>
<label class="md-nav__link " for="__nav_4" id="__nav_4_label" tabindex="0">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_4_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_4">
<span class="md-nav__icon md-icon"></span>
Blog
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_4_2" >
<label class="md-nav__link" for="__nav_4_2" id="__nav_4_2_label" tabindex="0">
<span class="md-ellipsis">
Archive
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="2" aria-labelledby="__nav_4_2_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_4_2">
<span class="md-nav__icon md-icon"></span>
Archive
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../blog/archive/2024/" class="md-nav__link">
<span class="md-ellipsis">
2024
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../blog/archive/2023/" class="md-nav__link">
<span class="md-ellipsis">
2023
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_4_3" >
<label class="md-nav__link" for="__nav_4_3" id="__nav_4_3_label" tabindex="0">
<span class="md-ellipsis">
Categories
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="2" aria-labelledby="__nav_4_3_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_4_3">
<span class="md-nav__icon md-icon"></span>
Categories
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../blog/category/releases/" class="md-nav__link">
<span class="md-ellipsis">
Releases
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../blog/category/wg21/" class="md-nav__link">
<span class="md-ellipsis">
WG21
</span>
</a>
</li>
</ul>
</nav>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../../release_notes/" class="md-nav__link">
<span class="md-ellipsis">
Release Notes
</span>
</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<a href="https://github.com/mpusz/mp-units/edit/master/docs/getting_started/quick_start.md" title="Edit this page" class="md-content__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M10 20H6V4h7v5h5v3.1l2-2V8l-6-6H6c-1.1 0-2 .9-2 2v16c0 1.1.9 2 2 2h4v-2m10.2-7c.1 0 .3.1.4.2l1.3 1.3c.2.2.2.6 0 .8l-1 1-2.1-2.1 1-1c.1-.1.2-.2.4-.2m0 3.9L14.1 23H12v-2.1l6.1-6.1 2.1 2.1Z"/></svg>
</a>
<a href="https://github.com/mpusz/mp-units/raw/master/docs/getting_started/quick_start.md" title="View source of this page" class="md-content__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M17 18c.56 0 1 .44 1 1s-.44 1-1 1-1-.44-1-1 .44-1 1-1m0-3c-2.73 0-5.06 1.66-6 4 .94 2.34 3.27 4 6 4s5.06-1.66 6-4c-.94-2.34-3.27-4-6-4m0 6.5a2.5 2.5 0 0 1-2.5-2.5 2.5 2.5 0 0 1 2.5-2.5 2.5 2.5 0 0 1 2.5 2.5 2.5 2.5 0 0 1-2.5 2.5M9.27 20H6V4h7v5h5v4.07c.7.08 1.36.25 2 .49V8l-6-6H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h4.5a8.15 8.15 0 0 1-1.23-2Z"/></svg>
</a>
<h1 id="quick-start">Quick Start<a class="headerlink" href="#quick-start" title="Permanent link">&para;</a></h1>
<p>This chapter provides a quick introduction to get you started with <strong>mp-units</strong>.
Much more details can be found in our <a href="../../users_guide/terms_and_definitions/">User's Guide</a>.</p>
<h2 id="quantities">Quantities<a class="headerlink" href="#quantities" title="Permanent link">&para;</a></h2>
<p>A <strong>quantity</strong> is a concrete amount of a unit representing a quantity type of a specified dimension with a
specific representation. It is represented in the library with a <code>quantity</code> class template.</p>
<p>The <a href="../../appendix/references/#SIBrochure">SI Brochure</a> says:</p>
<div class="admonition quote">
<p class="admonition-title">SI Brochure</p>
<p>The value of the quantity is the product of the number and the unit. The space between the number
and the unit is regarded as a multiplication sign (just as a space between units implies
multiplication).</p>
</div>
<p>Following the above, the value of a quantity in the <strong>mp-units</strong> library is created by multiplying
a number with a predefined unit:</p>
<div class="tabbed-set tabbed-alternate" data-tabs="1:2"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><input id="__tabbed_1_2" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">C++ modules</label><label for="__tabbed_1_2">Header files</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-0-1"><a id="__codelineno-0-1" name="__codelineno-0-1" href="#__codelineno-0-1"></a><span class="k">import</span><span class="w"> </span><span class="n">mp_units</span><span class="p">;</span>
</span><span id="__span-0-2"><a id="__codelineno-0-2" name="__codelineno-0-2" href="#__codelineno-0-2"></a>
</span><span id="__span-0-3"><a id="__codelineno-0-3" name="__codelineno-0-3" href="#__codelineno-0-3"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-0-4"><a id="__codelineno-0-4" name="__codelineno-0-4" href="#__codelineno-0-4"></a>
</span><span id="__span-0-5"><a id="__codelineno-0-5" name="__codelineno-0-5" href="#__codelineno-0-5"></a><span class="n">quantity</span><span class="w"> </span><span class="n">q</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">42</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">metre</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">second</span><span class="p">;</span>
</span></code></pre></div>
</div>
<div class="tabbed-block">
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-1-1"><a id="__codelineno-1-1" name="__codelineno-1-1" href="#__codelineno-1-1"></a><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;mp-units/systems/si.h&gt;</span>
</span><span id="__span-1-2"><a id="__codelineno-1-2" name="__codelineno-1-2" href="#__codelineno-1-2"></a>
</span><span id="__span-1-3"><a id="__codelineno-1-3" name="__codelineno-1-3" href="#__codelineno-1-3"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-1-4"><a id="__codelineno-1-4" name="__codelineno-1-4" href="#__codelineno-1-4"></a>
</span><span id="__span-1-5"><a id="__codelineno-1-5" name="__codelineno-1-5" href="#__codelineno-1-5"></a><span class="n">quantity</span><span class="w"> </span><span class="n">q</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">42</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">metre</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">second</span><span class="p">;</span>
</span></code></pre></div>
</div>
</div>
</div>
<div class="admonition info">
<p class="admonition-title">Info</p>
<p>In case someone doesn't like the multiply syntax or there is an ambiguity between <code>operator*</code>
provided by this and other libraries, a quantity can also be created with a two-parameter
constructor:</p>
<div class="tabbed-set tabbed-alternate" data-tabs="2:2"><input checked="checked" id="__tabbed_2_1" name="__tabbed_2" type="radio" /><input id="__tabbed_2_2" name="__tabbed_2" type="radio" /><div class="tabbed-labels"><label for="__tabbed_2_1">C++ modules</label><label for="__tabbed_2_2">Header files</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-2-1"><a id="__codelineno-2-1" name="__codelineno-2-1" href="#__codelineno-2-1"></a><span class="k">import</span><span class="w"> </span><span class="n">mp_units</span><span class="p">;</span>
</span><span id="__span-2-2"><a id="__codelineno-2-2" name="__codelineno-2-2" href="#__codelineno-2-2"></a>
</span><span id="__span-2-3"><a id="__codelineno-2-3" name="__codelineno-2-3" href="#__codelineno-2-3"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-2-4"><a id="__codelineno-2-4" name="__codelineno-2-4" href="#__codelineno-2-4"></a>
</span><span id="__span-2-5"><a id="__codelineno-2-5" name="__codelineno-2-5" href="#__codelineno-2-5"></a><span class="n">quantity</span><span class="w"> </span><span class="n">q</span><span class="p">{</span><span class="mi">42</span><span class="p">,</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">metre</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">second</span><span class="p">};</span>
</span></code></pre></div>
</div>
<div class="tabbed-block">
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-3-1"><a id="__codelineno-3-1" name="__codelineno-3-1" href="#__codelineno-3-1"></a><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;mp-units/systems/si.h&gt;</span>
</span><span id="__span-3-2"><a id="__codelineno-3-2" name="__codelineno-3-2" href="#__codelineno-3-2"></a>
</span><span id="__span-3-3"><a id="__codelineno-3-3" name="__codelineno-3-3" href="#__codelineno-3-3"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-3-4"><a id="__codelineno-3-4" name="__codelineno-3-4" href="#__codelineno-3-4"></a>
</span><span id="__span-3-5"><a id="__codelineno-3-5" name="__codelineno-3-5" href="#__codelineno-3-5"></a><span class="n">quantity</span><span class="w"> </span><span class="n">q</span><span class="p">{</span><span class="mi">42</span><span class="p">,</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">metre</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">second</span><span class="p">};</span>
</span></code></pre></div>
</div>
</div>
</div>
</div>
<p>The above creates an instance of <code>quantity&lt;derived_unit&lt;si::metre, per&lt;si::second&gt;&gt;{}, int&gt;</code>.
The same can be obtained using optional unit symbols:</p>
<div class="tabbed-set tabbed-alternate" data-tabs="3:2"><input checked="checked" id="__tabbed_3_1" name="__tabbed_3" type="radio" /><input id="__tabbed_3_2" name="__tabbed_3" type="radio" /><div class="tabbed-labels"><label for="__tabbed_3_1">C++ modules</label><label for="__tabbed_3_2">Header files</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-4-1"><a id="__codelineno-4-1" name="__codelineno-4-1" href="#__codelineno-4-1"></a><span class="k">import</span><span class="w"> </span><span class="n">mp_units</span><span class="p">;</span>
</span><span id="__span-4-2"><a id="__codelineno-4-2" name="__codelineno-4-2" href="#__codelineno-4-2"></a>
</span><span id="__span-4-3"><a id="__codelineno-4-3" name="__codelineno-4-3" href="#__codelineno-4-3"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-4-4"><a id="__codelineno-4-4" name="__codelineno-4-4" href="#__codelineno-4-4"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="o">::</span><span class="nn">si</span><span class="o">::</span><span class="nn">unit_symbols</span><span class="p">;</span>
</span><span id="__span-4-5"><a id="__codelineno-4-5" name="__codelineno-4-5" href="#__codelineno-4-5"></a>
</span><span id="__span-4-6"><a id="__codelineno-4-6" name="__codelineno-4-6" href="#__codelineno-4-6"></a><span class="n">quantity</span><span class="w"> </span><span class="n">q</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">42</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">m</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">s</span><span class="p">;</span>
</span></code></pre></div>
</div>
<div class="tabbed-block">
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-5-1"><a id="__codelineno-5-1" name="__codelineno-5-1" href="#__codelineno-5-1"></a><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;mp-units/systems/si.h&gt;</span>
</span><span id="__span-5-2"><a id="__codelineno-5-2" name="__codelineno-5-2" href="#__codelineno-5-2"></a>
</span><span id="__span-5-3"><a id="__codelineno-5-3" name="__codelineno-5-3" href="#__codelineno-5-3"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-5-4"><a id="__codelineno-5-4" name="__codelineno-5-4" href="#__codelineno-5-4"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="o">::</span><span class="nn">si</span><span class="o">::</span><span class="nn">unit_symbols</span><span class="p">;</span>
</span><span id="__span-5-5"><a id="__codelineno-5-5" name="__codelineno-5-5" href="#__codelineno-5-5"></a>
</span><span id="__span-5-6"><a id="__codelineno-5-6" name="__codelineno-5-6" href="#__codelineno-5-6"></a><span class="n">quantity</span><span class="w"> </span><span class="n">q</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">42</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">m</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">s</span><span class="p">;</span>
</span></code></pre></div>
</div>
</div>
</div>
<div class="admonition important">
<p class="admonition-title">Important</p>
<p>Unit symbols introduce a lot of short identifiers into the current scope, which may cause
naming collisions with unrelated but already existing identifiers in the code base.
This is why unit symbols are opt-in and typically should be imported only in the context
where they are being used (e.g., function scope).</p>
<p>A user has several options here to choose from depending on the required scenario and possible
naming conflicts:</p>
<div class="tabbed-set tabbed-alternate" data-tabs="4:4"><input checked="checked" id="__tabbed_4_1" name="__tabbed_4" type="radio" /><input id="__tabbed_4_2" name="__tabbed_4" type="radio" /><input id="__tabbed_4_3" name="__tabbed_4" type="radio" /><input id="__tabbed_4_4" name="__tabbed_4" type="radio" /><div class="tabbed-labels"><label for="__tabbed_4_1">using-directive</label><label for="__tabbed_4_2">using-declaration</label><label for="__tabbed_4_3">custom short identifier</label><label for="__tabbed_4_4">unit names</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<p>Explicitly "import" all of the symbols of a specific system of units from a dedicated
<code>unit_symbols</code> namespace with a
<a href="https://en.cppreference.com/w/cpp/language/namespace#Using-directives">using-directive</a>:</p>
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-6-1"><a id="__codelineno-6-1" name="__codelineno-6-1" href="#__codelineno-6-1"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-6-2"><a id="__codelineno-6-2" name="__codelineno-6-2" href="#__codelineno-6-2"></a>
</span><span id="__span-6-3"><a id="__codelineno-6-3" name="__codelineno-6-3" href="#__codelineno-6-3"></a><span class="kt">void</span><span class="w"> </span><span class="nf">foo</span><span class="p">(</span><span class="kt">double</span><span class="w"> </span><span class="n">speed_m_s</span><span class="p">)</span>
</span><span id="__span-6-4"><a id="__codelineno-6-4" name="__codelineno-6-4" href="#__codelineno-6-4"></a><span class="p">{</span>
</span><span id="__span-6-5"><a id="__codelineno-6-5" name="__codelineno-6-5" href="#__codelineno-6-5"></a><span class="w"> </span><span class="c1">// imports all the SI symbols at once</span>
</span><span id="__span-6-6"><a id="__codelineno-6-6" name="__codelineno-6-6" href="#__codelineno-6-6"></a><span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">si</span><span class="o">::</span><span class="nn">unit_symbols</span><span class="p">;</span>
</span><span id="__span-6-7"><a id="__codelineno-6-7" name="__codelineno-6-7" href="#__codelineno-6-7"></a><span class="w"> </span><span class="n">quantity</span><span class="w"> </span><span class="n">speed</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">speed_m_s</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">m</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">s</span><span class="p">;</span>
</span><span id="__span-6-8"><a id="__codelineno-6-8" name="__codelineno-6-8" href="#__codelineno-6-8"></a><span class="w"> </span><span class="c1">// ...</span>
</span><span id="__span-6-9"><a id="__codelineno-6-9" name="__codelineno-6-9" href="#__codelineno-6-9"></a><span class="p">}</span>
</span></code></pre></div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>This solution is perfect for small and isolated scopes but can cause surprising issues
when used in larger scopes or when used for the entire program namespace.</p>
<p>There are 29 named units in SI, and each of them has many prefixed variations (e.g.,
<code>ng</code>, <code>kcd</code>, ...). It is pretty easy to introduce a name collision with those.</p>
</div>
</div>
<div class="tabbed-block">
<p>Selectively bring only the required and not-conflicting symbols with
<a href="https://en.cppreference.com/w/cpp/language/using_declaration">using-declarations</a>:</p>
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-7-1"><a id="__codelineno-7-1" name="__codelineno-7-1" href="#__codelineno-7-1"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-7-2"><a id="__codelineno-7-2" name="__codelineno-7-2" href="#__codelineno-7-2"></a>
</span><span id="__span-7-3"><a id="__codelineno-7-3" name="__codelineno-7-3" href="#__codelineno-7-3"></a><span class="kt">void</span><span class="w"> </span><span class="nf">foo</span><span class="p">(</span><span class="kt">double</span><span class="w"> </span><span class="n">N</span><span class="p">)</span>
</span><span id="__span-7-4"><a id="__codelineno-7-4" name="__codelineno-7-4" href="#__codelineno-7-4"></a><span class="p">{</span>
</span><span id="__span-7-5"><a id="__codelineno-7-5" name="__codelineno-7-5" href="#__codelineno-7-5"></a><span class="w"> </span><span class="c1">// &#39;N&#39; function parameter would collide with the SI symbol for Newton, so we only bring what we need</span>
</span><span id="__span-7-6"><a id="__codelineno-7-6" name="__codelineno-7-6" href="#__codelineno-7-6"></a><span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">unit_symbols</span><span class="o">::</span><span class="n">m</span><span class="p">;</span>
</span><span id="__span-7-7"><a id="__codelineno-7-7" name="__codelineno-7-7" href="#__codelineno-7-7"></a><span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">unit_symbols</span><span class="o">::</span><span class="n">s</span><span class="p">;</span>
</span><span id="__span-7-8"><a id="__codelineno-7-8" name="__codelineno-7-8" href="#__codelineno-7-8"></a><span class="w"> </span><span class="n">quantity</span><span class="w"> </span><span class="n">speed</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">N</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">m</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">s</span><span class="p">;</span>
</span><span id="__span-7-9"><a id="__codelineno-7-9" name="__codelineno-7-9" href="#__codelineno-7-9"></a><span class="w"> </span><span class="c1">// ...</span>
</span><span id="__span-7-10"><a id="__codelineno-7-10" name="__codelineno-7-10" href="#__codelineno-7-10"></a><span class="p">}</span>
</span></code></pre></div>
</div>
<div class="tabbed-block">
<p>Specify a custom not conflicting unit identifier for a unit:</p>
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-8-1"><a id="__codelineno-8-1" name="__codelineno-8-1" href="#__codelineno-8-1"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-8-2"><a id="__codelineno-8-2" name="__codelineno-8-2" href="#__codelineno-8-2"></a>
</span><span id="__span-8-3"><a id="__codelineno-8-3" name="__codelineno-8-3" href="#__codelineno-8-3"></a><span class="kt">void</span><span class="w"> </span><span class="nf">foo</span><span class="p">(</span><span class="kt">double</span><span class="w"> </span><span class="n">speed_m_s</span><span class="p">)</span>
</span><span id="__span-8-4"><a id="__codelineno-8-4" name="__codelineno-8-4" href="#__codelineno-8-4"></a><span class="p">{</span>
</span><span id="__span-8-5"><a id="__codelineno-8-5" name="__codelineno-8-5" href="#__codelineno-8-5"></a><span class="w"> </span><span class="c1">// names of some local variables are conflicting with the symbols we want to use</span>
</span><span id="__span-8-6"><a id="__codelineno-8-6" name="__codelineno-8-6" href="#__codelineno-8-6"></a><span class="w"> </span><span class="k">auto</span><span class="w"> </span><span class="n">m</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">...;</span>
</span><span id="__span-8-7"><a id="__codelineno-8-7" name="__codelineno-8-7" href="#__codelineno-8-7"></a><span class="w"> </span><span class="k">auto</span><span class="w"> </span><span class="n">s</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">...;</span>
</span><span id="__span-8-8"><a id="__codelineno-8-8" name="__codelineno-8-8" href="#__codelineno-8-8"></a>
</span><span id="__span-8-9"><a id="__codelineno-8-9" name="__codelineno-8-9" href="#__codelineno-8-9"></a><span class="w"> </span><span class="k">constexpr</span><span class="w"> </span><span class="n">Unit</span><span class="w"> </span><span class="k">auto</span><span class="w"> </span><span class="n">mps</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">metre</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">second</span><span class="p">;</span>
</span><span id="__span-8-10"><a id="__codelineno-8-10" name="__codelineno-8-10" href="#__codelineno-8-10"></a><span class="w"> </span><span class="n">quantity</span><span class="w"> </span><span class="n">speed</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">speed_m_s</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">mps</span><span class="p">;</span>
</span><span id="__span-8-11"><a id="__codelineno-8-11" name="__codelineno-8-11" href="#__codelineno-8-11"></a><span class="p">}</span>
</span></code></pre></div>
</div>
<div class="tabbed-block">
<p>Full unit names are straightforward to use and often provide the most readable code:</p>
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-9-1"><a id="__codelineno-9-1" name="__codelineno-9-1" href="#__codelineno-9-1"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-9-2"><a id="__codelineno-9-2" name="__codelineno-9-2" href="#__codelineno-9-2"></a>
</span><span id="__span-9-3"><a id="__codelineno-9-3" name="__codelineno-9-3" href="#__codelineno-9-3"></a><span class="kt">void</span><span class="w"> </span><span class="nf">foo</span><span class="p">(</span><span class="kt">double</span><span class="w"> </span><span class="n">m</span><span class="p">,</span><span class="w"> </span><span class="kt">double</span><span class="w"> </span><span class="n">s</span><span class="p">)</span>
</span><span id="__span-9-4"><a id="__codelineno-9-4" name="__codelineno-9-4" href="#__codelineno-9-4"></a><span class="p">{</span>
</span><span id="__span-9-5"><a id="__codelineno-9-5" name="__codelineno-9-5" href="#__codelineno-9-5"></a><span class="w"> </span><span class="n">quantity</span><span class="w"> </span><span class="n">speed</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">m</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">metre</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="p">(</span><span class="n">s</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">si</span><span class="o">::</span><span class="n">second</span><span class="p">);</span>
</span><span id="__span-9-6"><a id="__codelineno-9-6" name="__codelineno-9-6" href="#__codelineno-9-6"></a><span class="w"> </span><span class="c1">// ...</span>
</span><span id="__span-9-7"><a id="__codelineno-9-7" name="__codelineno-9-7" href="#__codelineno-9-7"></a><span class="p">}</span>
</span></code></pre></div>
</div>
</div>
</div>
</div>
<p>Quantities of the same kind can be added, subtracted, and compared to each other:</p>
<div class="tabbed-set tabbed-alternate" data-tabs="5:2"><input checked="checked" id="__tabbed_5_1" name="__tabbed_5" type="radio" /><input id="__tabbed_5_2" name="__tabbed_5" type="radio" /><div class="tabbed-labels"><label for="__tabbed_5_1">C++ modules</label><label for="__tabbed_5_2">Header files</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-10-1"><a id="__codelineno-10-1" name="__codelineno-10-1" href="#__codelineno-10-1"></a><span class="k">import</span><span class="w"> </span><span class="n">mp_units</span><span class="p">;</span>
</span><span id="__span-10-2"><a id="__codelineno-10-2" name="__codelineno-10-2" href="#__codelineno-10-2"></a>
</span><span id="__span-10-3"><a id="__codelineno-10-3" name="__codelineno-10-3" href="#__codelineno-10-3"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-10-4"><a id="__codelineno-10-4" name="__codelineno-10-4" href="#__codelineno-10-4"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="o">::</span><span class="nn">si</span><span class="o">::</span><span class="nn">unit_symbols</span><span class="p">;</span>
</span><span id="__span-10-5"><a id="__codelineno-10-5" name="__codelineno-10-5" href="#__codelineno-10-5"></a>
</span><span id="__span-10-6"><a id="__codelineno-10-6" name="__codelineno-10-6" href="#__codelineno-10-6"></a><span class="k">static_assert</span><span class="p">(</span><span class="mi">1</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">km</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">50</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">m</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">1050</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">m</span><span class="p">);</span>
</span></code></pre></div>
</div>
<div class="tabbed-block">
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-11-1"><a id="__codelineno-11-1" name="__codelineno-11-1" href="#__codelineno-11-1"></a><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;mp-units/systems/si.h&gt;</span>
</span><span id="__span-11-2"><a id="__codelineno-11-2" name="__codelineno-11-2" href="#__codelineno-11-2"></a>
</span><span id="__span-11-3"><a id="__codelineno-11-3" name="__codelineno-11-3" href="#__codelineno-11-3"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-11-4"><a id="__codelineno-11-4" name="__codelineno-11-4" href="#__codelineno-11-4"></a><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="o">::</span><span class="nn">si</span><span class="o">::</span><span class="nn">unit_symbols</span><span class="p">;</span>
</span><span id="__span-11-5"><a id="__codelineno-11-5" name="__codelineno-11-5" href="#__codelineno-11-5"></a>
</span><span id="__span-11-6"><a id="__codelineno-11-6" name="__codelineno-11-6" href="#__codelineno-11-6"></a><span class="k">static_assert</span><span class="p">(</span><span class="mi">1</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">km</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">50</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">m</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">1050</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">m</span><span class="p">);</span>
</span></code></pre></div>
</div>
</div>
</div>
<p>Various quantities can be multiplied or divided by each other:</p>
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-12-1"><a id="__codelineno-12-1" name="__codelineno-12-1" href="#__codelineno-12-1"></a><span class="k">static_assert</span><span class="p">(</span><span class="mi">140</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">km</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="p">(</span><span class="mi">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">h</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">70</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">km</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">h</span><span class="p">);</span>
</span></code></pre></div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>In case you wonder why this library does not use UDLs to create quantities, please check
our <a href="../faq/#why-dont-we-use-udls-to-create-quantities">FAQ</a>.</p>
</div>
<h2 id="quantity-points">Quantity points<a class="headerlink" href="#quantity-points" title="Permanent link">&para;</a></h2>
<p>The quantity point specifies an absolute quantity with respect to an origin.
If no origin is provided explicitly, an implicit one will be provided by the library.</p>
<p>Together with quantities, they model <a href="../../users_guide/framework_basics/the_affine_space/">The Affine Space</a>.</p>
<p>Quantity points should be used in all places where adding two values is meaningless
(e.g., temperature points, timestamps, altitudes, readouts from the car's odometer, etc.).</p>
<p>The set of operations that can be done on quantity points is limited compared to quantities.
This introduces an additional type-safety.</p>
<div class="tabbed-set tabbed-alternate" data-tabs="6:2"><input checked="checked" id="__tabbed_6_1" name="__tabbed_6" type="radio" /><input id="__tabbed_6_2" name="__tabbed_6" type="radio" /><div class="tabbed-labels"><label for="__tabbed_6_1">C++ modules</label><label for="__tabbed_6_2">Header files</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-13-1"><a id="__codelineno-13-1" name="__codelineno-13-1" href="#__codelineno-13-1"></a><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;print&gt;</span>
</span><span id="__span-13-2"><a id="__codelineno-13-2" name="__codelineno-13-2" href="#__codelineno-13-2"></a><span class="k">import</span><span class="w"> </span><span class="n">mp_units</span><span class="p">;</span>
</span><span id="__span-13-3"><a id="__codelineno-13-3" name="__codelineno-13-3" href="#__codelineno-13-3"></a>
</span><span id="__span-13-4"><a id="__codelineno-13-4" name="__codelineno-13-4" href="#__codelineno-13-4"></a><span class="kt">int</span><span class="w"> </span><span class="nf">main</span><span class="p">()</span>
</span><span id="__span-13-5"><a id="__codelineno-13-5" name="__codelineno-13-5" href="#__codelineno-13-5"></a><span class="p">{</span>
</span><span id="__span-13-6"><a id="__codelineno-13-6" name="__codelineno-13-6" href="#__codelineno-13-6"></a><span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-13-7"><a id="__codelineno-13-7" name="__codelineno-13-7" href="#__codelineno-13-7"></a><span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="o">::</span><span class="nn">si</span><span class="o">::</span><span class="nn">unit_symbols</span><span class="p">;</span>
</span><span id="__span-13-8"><a id="__codelineno-13-8" name="__codelineno-13-8" href="#__codelineno-13-8"></a><span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="o">::</span><span class="nn">usc</span><span class="o">::</span><span class="nn">unit_symbols</span><span class="p">;</span>
</span><span id="__span-13-9"><a id="__codelineno-13-9" name="__codelineno-13-9" href="#__codelineno-13-9"></a>
</span><span id="__span-13-10"><a id="__codelineno-13-10" name="__codelineno-13-10" href="#__codelineno-13-10"></a><span class="w"> </span><span class="n">quantity_point</span><span class="w"> </span><span class="n">temp</span><span class="p">{</span><span class="mf">20.</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">deg_C</span><span class="p">};</span>
</span><span id="__span-13-11"><a id="__codelineno-13-11" name="__codelineno-13-11" href="#__codelineno-13-11"></a><span class="w"> </span><span class="n">std</span><span class="o">::</span><span class="n">println</span><span class="p">(</span><span class="s">&quot;Temperature: {} ({})&quot;</span><span class="p">,</span>
</span><span id="__span-13-12"><a id="__codelineno-13-12" name="__codelineno-13-12" href="#__codelineno-13-12"></a><span class="w"> </span><span class="n">temp</span><span class="p">.</span><span class="n">quantity_from_zero</span><span class="p">(),</span>
</span><span id="__span-13-13"><a id="__codelineno-13-13" name="__codelineno-13-13" href="#__codelineno-13-13"></a><span class="w"> </span><span class="n">temp</span><span class="p">.</span><span class="n">in</span><span class="p">(</span><span class="n">deg_F</span><span class="p">).</span><span class="n">quantity_from_zero</span><span class="p">());</span>
</span><span id="__span-13-14"><a id="__codelineno-13-14" name="__codelineno-13-14" href="#__codelineno-13-14"></a><span class="p">}</span>
</span></code></pre></div>
</div>
<div class="tabbed-block">
<div class="language-cpp highlight"><pre><span></span><code><span id="__span-14-1"><a id="__codelineno-14-1" name="__codelineno-14-1" href="#__codelineno-14-1"></a><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;mp-units/format.h&gt;</span>
</span><span id="__span-14-2"><a id="__codelineno-14-2" name="__codelineno-14-2" href="#__codelineno-14-2"></a><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;mp-units/systems/si.h&gt;</span>
</span><span id="__span-14-3"><a id="__codelineno-14-3" name="__codelineno-14-3" href="#__codelineno-14-3"></a><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;mp-units/systems/usc.h&gt;</span>
</span><span id="__span-14-4"><a id="__codelineno-14-4" name="__codelineno-14-4" href="#__codelineno-14-4"></a><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;print&gt;</span>
</span><span id="__span-14-5"><a id="__codelineno-14-5" name="__codelineno-14-5" href="#__codelineno-14-5"></a>
</span><span id="__span-14-6"><a id="__codelineno-14-6" name="__codelineno-14-6" href="#__codelineno-14-6"></a><span class="kt">int</span><span class="w"> </span><span class="nf">main</span><span class="p">()</span>
</span><span id="__span-14-7"><a id="__codelineno-14-7" name="__codelineno-14-7" href="#__codelineno-14-7"></a><span class="p">{</span>
</span><span id="__span-14-8"><a id="__codelineno-14-8" name="__codelineno-14-8" href="#__codelineno-14-8"></a><span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="p">;</span>
</span><span id="__span-14-9"><a id="__codelineno-14-9" name="__codelineno-14-9" href="#__codelineno-14-9"></a><span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="o">::</span><span class="nn">si</span><span class="o">::</span><span class="nn">unit_symbols</span><span class="p">;</span>
</span><span id="__span-14-10"><a id="__codelineno-14-10" name="__codelineno-14-10" href="#__codelineno-14-10"></a><span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">mp_units</span><span class="o">::</span><span class="nn">usc</span><span class="o">::</span><span class="nn">unit_symbols</span><span class="p">;</span>
</span><span id="__span-14-11"><a id="__codelineno-14-11" name="__codelineno-14-11" href="#__codelineno-14-11"></a>
</span><span id="__span-14-12"><a id="__codelineno-14-12" name="__codelineno-14-12" href="#__codelineno-14-12"></a><span class="w"> </span><span class="n">quantity_point</span><span class="w"> </span><span class="n">temp</span><span class="p">{</span><span class="mf">20.</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">deg_C</span><span class="p">};</span>
</span><span id="__span-14-13"><a id="__codelineno-14-13" name="__codelineno-14-13" href="#__codelineno-14-13"></a><span class="w"> </span><span class="n">std</span><span class="o">::</span><span class="n">println</span><span class="p">(</span><span class="s">&quot;Temperature: {} ({})&quot;</span><span class="p">,</span>
</span><span id="__span-14-14"><a id="__codelineno-14-14" name="__codelineno-14-14" href="#__codelineno-14-14"></a><span class="w"> </span><span class="n">temp</span><span class="p">.</span><span class="n">quantity_from_zero</span><span class="p">(),</span>
</span><span id="__span-14-15"><a id="__codelineno-14-15" name="__codelineno-14-15" href="#__codelineno-14-15"></a><span class="w"> </span><span class="n">temp</span><span class="p">.</span><span class="n">in</span><span class="p">(</span><span class="n">deg_F</span><span class="p">).</span><span class="n">quantity_from_zero</span><span class="p">());</span>
</span><span id="__span-14-16"><a id="__codelineno-14-16" name="__codelineno-14-16" href="#__codelineno-14-16"></a><span class="p">}</span>
</span></code></pre></div>
</div>
</div>
</div>
<p>The above outputs:</p>
<div class="language-text highlight"><pre><span></span><code><span id="__span-15-1"><a id="__codelineno-15-1" name="__codelineno-15-1" href="#__codelineno-15-1"></a>Temperature: 20 °C (68 °F)
</span></code></pre></div>
<div class="admonition info">
<p class="admonition-title">Info</p>
<p>Check <a href="../../users_guide/framework_basics/the_affine_space/">The Affine Space</a> chapter to learn
more about quantity points.</p>
</div>
</article>
</div>
<script>var target=document.getElementById(location.hash.slice(1));target&&target.name&&(target.checked=target.name.startsWith("__tabbed_"))</script>
</div>
<button type="button" class="md-top md-icon" data-md-component="top" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M13 20h-2V8l-5.5 5.5-1.42-1.42L12 4.16l7.92 7.92-1.42 1.42L13 8v12Z"/></svg>
Back to top
</button>
</main>
<footer class="md-footer">
<nav class="md-footer__inner md-grid" aria-label="Footer" >
<a href="../introduction/" class="md-footer__link md-footer__link--prev" aria-label="Previous: Introduction">
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
Previous
</span>
<div class="md-ellipsis">
Introduction
</div>
</div>
</a>
<a href="../look_and_feel/" class="md-footer__link md-footer__link--next" aria-label="Next: Look and Feel">
<div class="md-footer__title">
<span class="md-footer__direction">
Next
</span>
<div class="md-ellipsis">
Look and Feel
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
<div class="md-copyright__highlight">
Copyright &copy; 2018-2023 Mateusz Pusz
</div>
Made with
<a href="https://squidfunk.github.io/mkdocs-material/" target="_blank" rel="noopener">
Material for MkDocs
</a>
</div>
</div>
</div>
</footer>
</div>
<div class="md-dialog" data-md-component="dialog">
<div class="md-dialog__inner md-typeset"></div>
</div>
<script id="__config" type="application/json">{"base": "../..", "features": ["content.action.edit", "content.action.view", "content.code.annotate", "content.code.copy", "navigation.indexes", "navigation.tabs", "navigation.footer", "navigation.top", "search.highlight", "search.share", "search.suggest", "toc.follow", "toc.integrate"], "search": "../../assets/javascripts/workers/search.b8dbb3d2.min.js", "translations": {"clipboard.copied": "Copied to clipboard", "clipboard.copy": "Copy to clipboard", "search.result.more.one": "1 more on this page", "search.result.more.other": "# more on this page", "search.result.none": "No matching documents", "search.result.one": "1 matching document", "search.result.other": "# matching documents", "search.result.placeholder": "Type to start searching", "search.result.term.missing": "Missing", "select.version": "Select version"}, "version": {"provider": "mike"}}</script>
<script src="../../assets/javascripts/bundle.ad660dcc.min.js"></script>
<script src="../../javascripts/mathjax.js"></script>
<script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
<script src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
</body>
</html>
View Git Blame Copy Permalink