<!doctype html><html lang="en">
 <head>
  <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
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  <title>P1864R0: Defining Target Tuplets</title>
<style data-fill-with="stylesheet">/******************************************************************************
 *                   Style sheet for the W3C specifications                   *
 *
 * Special classes handled by this style sheet include:
 *
 * Indices
 *   - .toc for the Table of Contents (<ol class="toc">)
 *     + <span class="secno"> for the section numbers
 *   - #toc for the Table of Contents (<nav id="toc">)
 *   - ul.index for Indices (<a href="#ref">term</a><span>, in §N.M</span>)
 *   - table.index for Index Tables (e.g. for properties or elements)
 *
 * Structural Markup
 *   - table.data for general data tables
 *     -> use 'scope' attribute, <colgroup>, <thead>, and <tbody> for best results !
 *     -> use <table class='complex data'> for extra-complex tables
 *     -> use <td class='long'> for paragraph-length cell content
 *     -> use <td class='pre'> when manual line breaks/indentation would help readability
 *   - dl.switch for switch statements
 *   - ol.algorithm for algorithms (helps to visualize nesting)
 *   - .figure and .caption (HTML4) and figure and figcaption (HTML5)
 *     -> .sidefigure for right-floated figures
 *   - ins/del
 *
 * Code
 *   - pre and code
 *
 * Special Sections
 *   - .note       for informative notes             (div, p, span, aside, details)
 *   - .example    for informative examples          (div, p, pre, span)
 *   - .issue      for issues                        (div, p, span)
 *   - .assertion  for assertions                    (div, p, span)
 *   - .advisement for loud normative statements     (div, p, strong)
 *   - .annoying-warning for spec obsoletion notices (div, aside, details)
 *
 * Definition Boxes
 *   - pre.def   for WebIDL definitions
 *   - table.def for tables that define other entities (e.g. CSS properties)
 *   - dl.def    for definition lists that define other entitles (e.g. HTML elements)
 *
 * Numbering
 *   - .secno for section numbers in .toc and headings (<span class='secno'>3.2</span>)
 *   - .marker for source-inserted example/figure/issue numbers (<span class='marker'>Issue 4</span>)
 *   - ::before styled for CSS-generated issue/example/figure numbers:
 *     -> Documents wishing to use this only need to add
 *        figcaption::before,
 *        .caption::before { content: "Figure "  counter(figure) " ";  }
 *        .example::before { content: "Example " counter(example) " "; }
 *        .issue::before   { content: "Issue "   counter(issue) " ";   }
 *
 * Header Stuff (ignore, just don't conflict with these classes)
 *   - .head for the header
 *   - .copyright for the copyright
 *
 * Miscellaneous
 *   - .overlarge for things that should be as wide as possible, even if
 *     that overflows the body text area. This can be used on an item or
 *     on its container, depending on the effect desired.
 *     Note that this styling basically doesn't help at all when printing,
 *     since A4 paper isn't much wider than the max-width here.
 *     It's better to design things to fit into a narrower measure if possible.
 *   - js-added ToC jump links (see fixup.js)
 *
 ******************************************************************************/

/******************************************************************************/
/*                                   Body                                     */
/******************************************************************************/

	body {
		counter-reset: example figure issue;

		/* Layout */
		max-width: 50em;               /* limit line length to 50em for readability   */
		margin: 0 auto;                /* center text within page                     */
		padding: 1.6em 1.5em 2em 50px; /* assume 16px font size for downlevel clients */
		padding: 1.6em 1.5em 2em calc(26px + 1.5em); /* leave space for status flag     */

		/* Typography */
		line-height: 1.5;
		font-family: sans-serif;
		widows: 2;
		orphans: 2;
		word-wrap: break-word;
		overflow-wrap: break-word;
		hyphens: auto;

		/* Colors */
		color: black;
		background: white top left fixed no-repeat;
		background-size: 25px auto;
	}


/******************************************************************************/
/*                         Front Matter & Navigation                          */
/******************************************************************************/

/** Header ********************************************************************/

	div.head { margin-bottom: 1em }
	div.head hr { border-style: solid; }

	div.head h1 {
		font-weight: bold;
		margin: 0 0 .1em;
		font-size: 220%;
	}

	div.head h2 { margin-bottom: 1.5em;}

/** W3C Logo ******************************************************************/

	.head .logo {
		float: right;
		margin: 0.4rem 0 0.2rem .4rem;
	}

	.head img[src*="logos/W3C"] {
		display: block;
		border: solid #1a5e9a;
		border-width: .65rem .7rem .6rem;
		border-radius: .4rem;
		background: #1a5e9a;
		color: white;
		font-weight: bold;
	}

	.head a:hover > img[src*="logos/W3C"],
	.head a:focus > img[src*="logos/W3C"] {
		opacity: .8;
	}

	.head a:active > img[src*="logos/W3C"] {
		background: #c00;
		border-color: #c00;
	}

	/* see also additional rules in Link Styling section */

/** Copyright *****************************************************************/

	p.copyright,
	p.copyright small { font-size: small }

/** Back to Top / ToC Toggle **************************************************/

	@media print {
		#toc-nav {
			display: none;
		}
	}
	@media not print {
		#toc-nav {
			position: fixed;
			z-index: 2;
			bottom: 0; left: 0;
			margin: 0;
			min-width: 1.33em;
			border-top-right-radius: 2rem;
			box-shadow: 0 0 2px;
			font-size: 1.5em;
			color: black;
		}
		#toc-nav > a {
			display: block;
			white-space: nowrap;

			height: 1.33em;
			padding: .1em 0.3em;
			margin: 0;

			background: white;
			box-shadow: 0 0 2px;
			border: none;
			border-top-right-radius: 1.33em;
			background: white;
		}
		#toc-nav > #toc-jump {
			padding-bottom: 2em;
			margin-bottom: -1.9em;
		}

		#toc-nav > a:hover,
		#toc-nav > a:focus {
			background: #f8f8f8;
		}
		#toc-nav > a:not(:hover):not(:focus) {
			color: #707070;
		}

		/* statusbar gets in the way on keyboard focus; remove once browsers fix */
		#toc-nav > a[href="#toc"]:not(:hover):focus:last-child {
			padding-bottom: 1.5rem;
		}

		#toc-nav:not(:hover) > a:not(:focus) > span + span {
			/* Ideally this uses :focus-within on #toc-nav */
			display: none;
		}
		#toc-nav > a > span + span {
			padding-right: 0.2em;
		}

		#toc-toggle-inline {
			vertical-align: 0.05em;
			font-size: 80%;
			color: gray;
			color: hsla(203,20%,40%,.7);
			border-style: none;
			background: transparent;
			position: relative;
		}
		#toc-toggle-inline:hover:not(:active),
		#toc-toggle-inline:focus:not(:active) {
			text-shadow: 1px 1px silver;
			top: -1px;
			left: -1px;
		}

		#toc-nav :active {
			color: #C00;
		}
	}

/** ToC Sidebar ***************************************************************/

	/* Floating sidebar */
	@media screen {
		body.toc-sidebar #toc {
			position: fixed;
			top: 0; bottom: 0;
			left: 0;
			width: 23.5em;
			max-width: 80%;
			max-width: calc(100% - 2em - 26px);
			overflow: auto;
			padding: 0 1em;
			padding-left: 42px;
			padding-left: calc(1em + 26px);
			background: inherit;
			background-color: #f7f8f9;
			z-index: 1;
			box-shadow: -.1em 0 .25em rgba(0,0,0,.1) inset;
		}
		body.toc-sidebar #toc h2 {
			margin-top: .8rem;
			font-variant: small-caps;
			font-variant: all-small-caps;
			text-transform: lowercase;
			font-weight: bold;
			color: gray;
			color: hsla(203,20%,40%,.7);
		}
		body.toc-sidebar #toc-jump:not(:focus) {
			width: 0;
			height: 0;
			padding: 0;
			position: absolute;
			overflow: hidden;
		}
	}
	/* Hide main scroller when only the ToC is visible anyway */
	@media screen and (max-width: 28em) {
		body.toc-sidebar {
			overflow: hidden;
		}
	}

	/* Sidebar with its own space */
	@media screen and (min-width: 78em) {
		body:not(.toc-inline) #toc {
			position: fixed;
			top: 0; bottom: 0;
			left: 0;
			width: 23.5em;
			overflow: auto;
			padding: 0 1em;
			padding-left: 42px;
			padding-left: calc(1em + 26px);
			background: inherit;
			background-color: #f7f8f9;
			z-index: 1;
			box-shadow: -.1em 0 .25em rgba(0,0,0,.1) inset;
		}
		body:not(.toc-inline) #toc h2 {
			margin-top: .8rem;
			font-variant: small-caps;
			font-variant: all-small-caps;
			text-transform: lowercase;
			font-weight: bold;
			color: gray;
			color: hsla(203,20%,40%,.7);
		}

		body:not(.toc-inline) {
			padding-left: 29em;
		}
		/* See also Overflow section at the bottom */

		body:not(.toc-inline) #toc-jump:not(:focus) {
			width: 0;
			height: 0;
			padding: 0;
			position: absolute;
			overflow: hidden;
		}
	}
	@media screen and (min-width: 90em) {
		body:not(.toc-inline) {
			margin: 0 4em;
		}
	}

/******************************************************************************/
/*                                Sectioning                                  */
/******************************************************************************/

/** Headings ******************************************************************/

	h1, h2, h3, h4, h5, h6, dt {
		page-break-after: avoid;
		page-break-inside: avoid;
		font: 100% sans-serif;   /* Reset all font styling to clear out UA styles */
		font-family: inherit;    /* Inherit the font family. */
		line-height: 1.2;        /* Keep wrapped headings compact */
		hyphens: manual;         /* Hyphenated headings look weird */
	}

	h2, h3, h4, h5, h6 {
		margin-top: 3rem;
	}

	h1, h2, h3 {
		color: #005A9C;
		background: transparent;
	}

	h1 { font-size: 170%; }
	h2 { font-size: 140%; }
	h3 { font-size: 120%; }
	h4 { font-weight: bold; }
	h5 { font-style: italic; }
	h6 { font-variant: small-caps; }
	dt { font-weight: bold; }

/** Subheadings ***************************************************************/

	h1 + h2,
	#subtitle {
		/* #subtitle is a subtitle in an H2 under the H1 */
		margin-top: 0;
	}
	h2 + h3,
	h3 + h4,
	h4 + h5,
	h5 + h6 {
		margin-top: 1.2em; /* = 1 x line-height */
	}

/** Section divider ***********************************************************/

	:not(.head) > hr {
		font-size: 1.5em;
		text-align: center;
		margin: 1em auto;
		height: auto;
		border: transparent solid 0;
		background: transparent;
	}
	:not(.head) > hr::before {
		content: "\2727\2003\2003\2727\2003\2003\2727";
	}

/******************************************************************************/
/*                            Paragraphs and Lists                            */
/******************************************************************************/

	p {
		margin: 1em 0;
	}

	dd > p:first-child,
	li > p:first-child {
		margin-top: 0;
	}

	ul, ol {
		margin-left: 0;
		padding-left: 2em;
	}

	li {
		margin: 0.25em 0 0.5em;
		padding: 0;
	}

	dl dd {
		margin: 0 0 .5em 2em;
	}

	.head dd + dd { /* compact for header */
		margin-top: -.5em;
	}

	/* Style for algorithms */
	ol.algorithm ol:not(.algorithm),
	.algorithm > ol ol:not(.algorithm) {
	 border-left: 0.5em solid #DEF;
	}

	/* Put nice boxes around each algorithm. */
	[data-algorithm]:not(.heading) {
	  padding: .5em;
	  border: thin solid #ddd; border-radius: .5em;
	  margin: .5em calc(-0.5em - 1px);
	}
	[data-algorithm]:not(.heading) > :first-child {
	  margin-top: 0;
	}
	[data-algorithm]:not(.heading) > :last-child {
	  margin-bottom: 0;
	}

	/* Style for switch/case <dl>s */
	dl.switch > dd > ol.only,
	dl.switch > dd > .only > ol {
	 margin-left: 0;
	}
	dl.switch > dd > ol.algorithm,
	dl.switch > dd > .algorithm > ol {
	 margin-left: -2em;
	}
	dl.switch {
	 padding-left: 2em;
	}
	dl.switch > dt {
	 text-indent: -1.5em;
	 margin-top: 1em;
	}
	dl.switch > dt + dt {
	 margin-top: 0;
	}
	dl.switch > dt::before {
	 content: '\21AA';
	 padding: 0 0.5em 0 0;
	 display: inline-block;
	 width: 1em;
	 text-align: right;
	 line-height: 0.5em;
	}

/** Terminology Markup ********************************************************/


/******************************************************************************/
/*                                 Inline Markup                              */
/******************************************************************************/

/** Terminology Markup ********************************************************/
	dfn   { /* Defining instance */
		font-weight: bolder;
	}
	a > i { /* Instance of term */
		font-style: normal;
	}
	dt dfn code, code.idl {
		font-size: medium;
	}
	dfn var {
		font-style: normal;
	}

/** Change Marking ************************************************************/

	del { color: red;  text-decoration: line-through; }
	ins { color: #080; text-decoration: underline;    }

/** Miscellaneous improvements to inline formatting ***************************/

	sup {
		vertical-align: super;
		font-size: 80%
	}

/******************************************************************************/
/*                                    Code                                    */
/******************************************************************************/

/** General monospace/pre rules ***********************************************/

	pre, code, samp {
		font-family: Menlo, Consolas, "DejaVu Sans Mono", Monaco, monospace;
		font-size: .9em;
		page-break-inside: avoid;
		hyphens: none;
		text-transform: none;
	}
	pre code,
	code code {
		font-size: 100%;
	}

	pre {
		margin-top: 1em;
		margin-bottom: 1em;
		overflow: auto;
	}

/** Inline Code fragments *****************************************************/

  /* Do something nice. */

/******************************************************************************/
/*                                    Links                                   */
/******************************************************************************/

/** General Hyperlinks ********************************************************/

	/* We hyperlink a lot, so make it less intrusive */
	a[href] {
		color: #034575;
		text-decoration: none;
		border-bottom: 1px solid #707070;
		/* Need a bit of extending for it to look okay */
		padding: 0 1px 0;
		margin: 0 -1px 0;
	}
	a:visited {
		border-bottom-color: #BBB;
	}

	/* Use distinguishing colors when user is interacting with the link */
	a[href]:focus,
	a[href]:hover {
		background: #f8f8f8;
		background: rgba(75%, 75%, 75%, .25);
		border-bottom-width: 3px;
		margin-bottom: -2px;
	}
	a[href]:active {
		color: #C00;
		border-color: #C00;
	}

	/* Backout above styling for W3C logo */
	.head .logo,
	.head .logo a {
		border: none;
		text-decoration: none;
		background: transparent;
	}

/******************************************************************************/
/*                                    Images                                  */
/******************************************************************************/

	img {
		border-style: none;
	}

	/* For autogen numbers, add
	   .caption::before, figcaption::before { content: "Figure " counter(figure) ". "; }
	*/

	figure, .figure, .sidefigure {
		page-break-inside: avoid;
		text-align: center;
		margin: 2.5em 0;
	}
	.figure img,    .sidefigure img,    figure img,
	.figure object, .sidefigure object, figure object {
		max-width: 100%;
		margin: auto;
	}
	.figure pre, .sidefigure pre, figure pre {
		text-align: left;
		display: table;
		margin: 1em auto;
	}
	.figure table, figure table {
		margin: auto;
	}
	@media screen and (min-width: 20em) {
		.sidefigure {
			float: right;
			width: 50%;
			margin: 0 0 0.5em 0.5em
		}
	}
	.caption, figcaption, caption {
		font-style: italic;
		font-size: 90%;
	}
	.caption::before, figcaption::before, figcaption > .marker {
		font-weight: bold;
	}
	.caption, figcaption {
		counter-increment: figure;
	}

	/* DL list is indented 2em, but figure inside it is not */
	dd > .figure, dd > figure { margin-left: -2em }

/******************************************************************************/
/*                             Colored Boxes                                  */
/******************************************************************************/

	.issue, .note, .example, .assertion, .advisement, blockquote {
		padding: .5em;
		border: .5em;
		border-left-style: solid;
		page-break-inside: avoid;
	}
	span.issue, span.note {
		padding: .1em .5em .15em;
		border-right-style: solid;
	}

	.issue,
	.note,
	.example,
	.advisement,
	.assertion,
	blockquote {
		margin: 1em auto;
	}
	.note  > p:first-child,
	.issue > p:first-child,
	blockquote > :first-child {
		margin-top: 0;
	}
	blockquote > :last-child {
		margin-bottom: 0;
	}

/** Blockquotes ***************************************************************/

	blockquote {
		border-color: silver;
	}

/** Open issue ****************************************************************/

	.issue {
		border-color: #E05252;
		background: #FBE9E9;
		counter-increment: issue;
		overflow: auto;
	}
	.issue::before, .issue > .marker {
		text-transform: uppercase;
		color: #AE1E1E;
		padding-right: 1em;
		text-transform: uppercase;
	}
	/* Add .issue::before { content: "Issue " counter(issue) " "; } for autogen numbers,
	   or use class="marker" to mark up the issue number in source. */

/** Example *******************************************************************/

	.example {
		border-color: #E0CB52;
		background: #FCFAEE;
		counter-increment: example;
		overflow: auto;
		clear: both;
	}
	.example::before, .example > .marker {
		text-transform: uppercase;
		color: #827017;
		min-width: 7.5em;
		display: block;
	}
	/* Add .example::before { content: "Example " counter(example) " "; } for autogen numbers,
	   or use class="marker" to mark up the example number in source. */

/** Non-normative Note ********************************************************/

	.note {
		border-color: #52E052;
		background: #E9FBE9;
		overflow: auto;
	}

	.note::before, .note > .marker,
	details.note > summary::before,
	details.note > summary > .marker {
		text-transform: uppercase;
		display: block;
		color: hsl(120, 70%, 30%);
	}
	/* Add .note::before { content: "Note"; } for autogen label,
	   or use class="marker" to mark up the label in source. */

	details.note > summary {
		display: block;
		color: hsl(120, 70%, 30%);
	}
	details.note[open] > summary {
		border-bottom: 1px silver solid;
	}

/** Assertion Box *************************************************************/
	/*  for assertions in algorithms */

	.assertion {
		border-color: #AAA;
		background: #EEE;
	}

/** Advisement Box ************************************************************/
	/*  for attention-grabbing normative statements */

	.advisement {
		border-color: orange;
		border-style: none solid;
		background: #FFEECC;
	}
	strong.advisement {
		display: block;
		text-align: center;
	}
	.advisement > .marker {
		color: #B35F00;
	}

/** Spec Obsoletion Notice ****************************************************/
	/* obnoxious obsoletion notice for older/abandoned specs. */

	details {
		display: block;
	}
	summary {
		font-weight: bolder;
	}

	.annoying-warning:not(details),
	details.annoying-warning:not([open]) > summary,
	details.annoying-warning[open] {
		background: #fdd;
		color: red;
		font-weight: bold;
		padding: .75em 1em;
		border: thick red;
		border-style: solid;
		border-radius: 1em;
	}
	.annoying-warning :last-child {
		margin-bottom: 0;
	}

@media not print {
	details.annoying-warning[open] {
		position: fixed;
		left: 1em;
		right: 1em;
		bottom: 1em;
		z-index: 1000;
	}
}

	details.annoying-warning:not([open]) > summary {
		text-align: center;
	}

/** Entity Definition Boxes ***************************************************/

	.def {
		padding: .5em 1em;
		background: #DEF;
		margin: 1.2em 0;
		border-left: 0.5em solid #8CCBF2;
	}

/******************************************************************************/
/*                                    Tables                                  */
/******************************************************************************/

	th, td {
		text-align: left;
		text-align: start;
	}

/** Property/Descriptor Definition Tables *************************************/

	table.def {
		/* inherits .def box styling, see above */
		width: 100%;
		border-spacing: 0;
	}

	table.def td,
	table.def th {
		padding: 0.5em;
		vertical-align: baseline;
		border-bottom: 1px solid #bbd7e9;
	}

	table.def > tbody > tr:last-child th,
	table.def > tbody > tr:last-child td {
		border-bottom: 0;
	}

	table.def th {
		font-style: italic;
		font-weight: normal;
		padding-left: 1em;
		width: 3em;
	}

	/* For when values are extra-complex and need formatting for readability */
	table td.pre {
		white-space: pre-wrap;
	}

	/* A footnote at the bottom of a def table */
	table.def           td.footnote {
		padding-top: 0.6em;
	}
	table.def           td.footnote::before {
		content: " ";
		display: block;
		height: 0.6em;
		width: 4em;
		border-top: thin solid;
	}

/** Data tables (and properly marked-up index tables) *************************/
	/*
		 <table class="data"> highlights structural relationships in a table
		 when correct markup is used (e.g. thead/tbody, th vs. td, scope attribute)

		 Use class="complex data" for particularly complicated tables --
		 (This will draw more lines: busier, but clearer.)

		 Use class="long" on table cells with paragraph-like contents
		 (This will adjust text alignment accordingly.)
		 Alternately use class="longlastcol" on tables, to have the last column assume "long".
	*/

	table {
		word-wrap: normal;
		overflow-wrap: normal;
		hyphens: manual;
	}

	table.data,
	table.index {
		margin: 1em auto;
		border-collapse: collapse;
		border: hidden;
		width: 100%;
	}
	table.data caption,
	table.index caption {
		max-width: 50em;
		margin: 0 auto 1em;
	}

	table.data td,  table.data th,
	table.index td, table.index th {
		padding: 0.5em 1em;
		border-width: 1px;
		border-color: silver;
		border-top-style: solid;
	}

	table.data thead td:empty {
		padding: 0;
		border: 0;
	}

	table.data  thead,
	table.index thead,
	table.data  tbody,
	table.index tbody {
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 <body class="h-entry">
  <div class="head">
   <p data-fill-with="logo"></p>
   <h1 class="p-name no-ref" id="title">P1864R0<br>Defining Target Tuplets</h1>
   <h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Published Proposal, <time class="dt-updated" datetime="2020-07-08">2020-07-08</time></span></h2>
   <div data-fill-with="spec-metadata">
    <dl>
     <dt>This version:
     <dd><a class="u-url" href="https://wg21.link/P1864R0">https://wg21.link/P1864R0</a>
     <dt>Latest published version:
     <dd><a href="https://wg21.link/P1864">https://wg21.link/P1864</a>
     <dt>Author:
     <dd>
      <dd class="editor p-author h-card vcard"><a class="p-name fn u-email email" href="mailto:imuerte@hey.com">Isabella Muerte</a>
     <dt>Audience:
     <dd>SG15
     <dt>Project:
     <dd>ISO/IEC JTC1/SC22/WG21 14882: Programming Language — C++
     <dt>Latest source:
     <dd><a href="https://github.com/slurps-mad-rips/papers/blob/HEAD/src/target-tuplets.bs">src/target-tuplets.bs</a>
     <dt>This source:
     <dd><a href="https://github.com/slurps-mad-rips/papers/blob/HEAD/src/target-tuplets.bs">src/target-tuplets.bs</a>
    </dl>
   </div>
   <div data-fill-with="warning"></div>
   <hr title="Separator for header">
  </div>
  <nav data-fill-with="table-of-contents" id="toc">
   <h2 class="no-num no-toc no-ref" id="contents">Table of Contents</h2>
   <ol class="toc" role="directory">
    <li>
     <a href="#changelog"><span class="secno">1</span> <span class="content">Revision History</span></a>
     <ol class="toc">
      <li><a href="#r0"><span class="secno">1.1</span> <span class="content">Revision 0</span></a>
     </ol>
    <li>
     <a href="#motivation"><span class="secno">2</span> <span class="content">Motivation</span></a>
     <ol class="toc">
      <li><a href="#tuplet"><span class="secno">2.1</span> <span class="content">Why Tuplet instead of Triplet or Tuple?</span></a>
     </ol>
    <li><a href="#design"><span class="secno">3</span> <span class="content">Design Considerations</span></a>
    <li>
     <a href="#wording"><span class="secno">4</span> <span class="content">Wording</span></a>
     <ol class="toc">
      <li><a href="#terms-and-definitions"><span class="secno">4.1</span> <span class="content">Terms and Definitions</span></a>
      <li>
       <a href="#target-tuplet"><span class="secno">4.2</span> <span class="content">Target Tuplet</span></a>
       <ol class="toc">
        <li><a href="#general"><span class="secno">4.2.1</span> <span class="content">In general</span></a>
       </ol>
      <li>
       <a href="#component-descriptions"><span class="secno">4.3</span> <span class="content">Component Descriptions</span></a>
       <ol class="toc">
        <li><a href="#component-architecture"><span class="secno">4.3.1</span> <span class="content">Architecture</span></a>
        <li><a href="#component-vendor"><span class="secno">4.3.2</span> <span class="content">Vendor</span></a>
        <li><a href="#component-operating-system"><span class="secno">4.3.3</span> <span class="content">Operating System</span></a>
        <li><a href="#component-environment"><span class="secno">4.3.4</span> <span class="content">Environment</span></a>
        <li><a href="#component-resolution"><span class="secno">4.3.5</span> <span class="content">Resolution</span></a>
       </ol>
     </ol>
    <li>
     <a href="#explanation"><span class="secno">5</span> <span class="content">Informative Explanation</span></a>
     <ol class="toc">
      <li><a href="#brief-history"><span class="secno">5.1</span> <span class="content">A Brief History of Compiler Targets</span></a>
      <li><a href="#vendor"><span class="secno">5.2</span> <span class="content">Why Vendor Over Machine</span></a>
      <li><a href="#environment"><span class="secno">5.3</span> <span class="content">Why environment over X</span></a>
     </ol>
    <li>
     <a href="#references"><span class="secno"></span> <span class="content">References</span></a>
     <ol class="toc">
      <li><a href="#informative"><span class="secno"></span> <span class="content">Informative References</span></a>
     </ol>
   </ol>
  </nav>
  <main>
   <h2 class="heading settled" data-level="1" id="changelog"><span class="secno">1. </span><span class="content">Revision History</span><a class="self-link" href="#changelog"></a></h2>
   <h3 class="heading settled" data-level="1.1" id="r0"><span class="secno">1.1. </span><span class="content">Revision 0</span><a class="self-link" href="#r0"></a></h3>
   <p>Initial release. 🎉</p>
   <h2 class="heading settled" data-level="2" id="motivation"><span class="secno">2. </span><span class="content">Motivation</span><a class="self-link" href="#motivation"></a></h2>
   <p>One of the more difficult things in the vast breadth of build systems is
declaring what system architecture, vendor, operating system, and environment
is used when compiling for a given platform. In some cases, these names are
chosen at random by various implementations and differ from each vendor. While
some time ago these would have been called "Target Triples", in practice they
have been "Target Tuplets".</p>
   <p>This paper aims to define and describe the concept of a target tuplet and how
they can be consumed by build systems, toolchains, and users alike. This paper <em>does not</em> attempt to define or limit existing target tuplets and instead
defers this "definition list" to a separate Standing Document. The reason for
this is that updating target tuplets with a Technical Report or Standard
requires several years to be updated and voted in. This model can’t react to
changes in existing practices, while a Standing Document can be updated at each
plenary vote, or simply be updated by an editor, and published at will.</p>
   <p>This paper might give examples of existing target tuplets, but this is for
demonstration purposes and is not to be taken as a guarantee that the tuplet
will exist in such a form in the future.</p>
   <p>Lastly, this paper also does not attempt to define a <em>sysroot</em>. That may or may
not be defined by a future separate paper.</p>
   <h3 class="heading settled" data-level="2.1" id="tuplet"><span class="secno">2.1. </span><span class="content">Why Tuplet instead of Triplet or Tuple?</span><a class="self-link" href="#tuplet"></a></h3>
   <p>Traditionally, a target tuplet has been called a <em>triplet</em>, as this referred to
the <em>architecture</em>, the <em>operating system</em>, and the <em>environment</em>. However, as time
has gone on, a 4th field was added, while the name <em>triplet</em> was kept. While
the author is not a verified expert on the English language, <em>triple</em> and the <em>number 4</em> do not mean the same thing.</p>
   <p>Additionally, C++ has the concept of a <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>tuple</c-></code>. The author opted to select
the term <em>tuplet</em> to remove any possibly ambiguity regarding discussions of
the definition found within this proposal.</p>
   <p>Lastly, the <code class="highlight"><c- o>-</c-><c- n>et</c-></code> and <code class="highlight"><c- o>-</c-><c- n>ette</c-></code> suffixes are used to describe something small
(e.g., a cas<em>ette</em> is a small case). However, <code class="highlight"><c- o>-</c-><c- n>et</c-></code> also means a group or
grouping, such as in the definition of oct<em>et</em>. A target tuplet is a grouping
of several elements regarding a target, hence the use of the term <em>tuplet</em> and
not <em>tuplette</em>.</p>
   <h2 class="heading settled" data-level="3" id="design"><span class="secno">3. </span><span class="content">Design Considerations</span><a class="self-link" href="#design"></a></h2>
   <p>A target tuplet is written (in utf-8) as a series of words (text), delimited
via a "hyphen-minus" (-). The current layout of a target tuplet is borrowed
from <a data-link-type="biblio" href="#biblio-clang-cross-compile">clang</a>, as other compilers tend to support this
layout but also provide alternative layouts that are incompatible with clang or
each other.</p>
   <p>Typically, a target tuplet <em>does not</em> infer floating point ABI, processor
specific intrinsics, or FPU specific intrinsics. These are more granular and
defining them at a broad scope is, in the authors opinion, fruitless.</p>
   <p>Lastly, a target tuplet can be considered "ill-formed, no diagnostic required"
if an incorrect sequence is put together and passed to the compiler. For
example, specifying <code class="highlight"><c- n>mips</c-><c- o>-</c-><c- n>ibm</c-><c- o>-</c-><c- n>cuda</c-><c- o>-</c-><c- n>macho</c-></code> as a target would most likely not
work in any existing compiler (at the time of this writing).  Instead, it is up
to users and build systems to ensure that these incorrect sequences do not make
their way to the compiler. This differs from clang’s approach, which is to
convert any unrecognized entries as <code class="highlight"><c- n>unknown</c-></code>, and then infer specifics.</p>
   <h2 class="heading settled" data-level="4" id="wording"><span class="secno">4. </span><span class="content">Wording</span><a class="self-link" href="#wording"></a></h2>
   <h3 class="heading settled" data-level="4.1" id="terms-and-definitions"><span class="secno">4.1. </span><span class="content">Terms and Definitions</span><a class="self-link" href="#terms-and-definitions"></a></h3>
   <p>For the purposes of this document, the following terms apply</p>
   <dl>
    <dt data-md><em>build system</em>
    <dd data-md>
     <p>A program that will drive the execution of a C++ compiler on a set of
 translation units. They live a level above the compiler, and thus are
 technically out of scope for the C++ standard document itself.</p>
    <dt data-md><em>platform</em>
    <dd data-md>
     <p>The inverse of the C++ abstract machine. That is, a concrete set of
 compilers, tools, programs, and code necessary to execute a program.
 Colloquially referred to as a system in some spaces.</p>
    <dt data-md><em>vendor</em>
    <dd data-md>
     <p>An entity that provides an implementation of a C++ toolchain.</p>
    <dt data-md><em>host</em>
    <dd data-md>
     <p>A specific instance of a platform, upon which the C++ compiler executes.
 [<em>Note</em>: The C++ standard does not mandate that a C++ compiler must be a
 well-formed program itself —<wbr><em>end note</em>]</p>
    <dt data-md><em>target</em>
    <dd data-md>
     <p>A specific instance of a platform, upon which a well-formed program is
 planned to execute</p>
    <dt data-md><em>machine</em>
    <dd data-md>
     <p>A specific instance of a target, upon which a well-formed program can run.</p>
    <dt data-md><em>object file format</em>
    <dd data-md>
     <p>The detailed file format a translation unit is in prior to linking.</p>
    <dt data-md><em>executable file format</em>
    <dd data-md>
     <p>The detailed file format a program is in once linked.</p>
   </dl>
   <h3 class="heading settled" data-level="4.2" id="target-tuplet"><span class="secno">4.2. </span><span class="content">Target Tuplet</span><a class="self-link" href="#target-tuplet"></a></h3>
   <h4 class="heading settled" data-level="4.2.1" id="general"><span class="secno">4.2.1. </span><span class="content">In general</span><a class="self-link" href="#general"></a></h4>
   <p><sup>1</sup> Target tuplets are a series of components used to represent a human
friendly phrase for a compiler target. They are useful for discussing minimum
feature sets for a code base, as well as what platform a program is expected to
compile and execute on.To be able to create a well-formed program for a given
target, a build system must know the details of how to invoke a compiler,
invoke a linker, and produce a final program or collection of object files.</p>
   <p><sup>2</sup> Since build systems live outside of the standard, they must be able
to invoke one or more compilers, regardless of whether they are from the same
vendor. This document defines 4 parts that make up a target tuplet.</p>
   <p><sup>3</sup> The 4 parts that make up a target tuplet are</p>
   <dl>
    <dt data-md>
    <dd data-md>
     <p><sup>(3.1)</sup> — architecture</p>
    <dd data-md>
     <p><sup>(3.2)</sup> — vendor</p>
    <dd data-md>
     <p><sup>(3.2)</sup> — operating system</p>
    <dd data-md>
     <p><sup>(3.2)</sup> — environment</p>
   </dl>
   <p>respectively. The generic term <em>component</em> refers to any portion of a target
tuplet that meets the above criteria.</p>
   <p><sup>4</sup> Target tuplets are constructed by concatenating the content of
all components with the hypen-minus character (-). Components are not
permitted to contain the hyphen-minus themselves.</p>
   <p><sup>5</sup> A target tuplet is considered well-formed if a compiler is able to
understand the 4 components provided. Likewise, if a compiler is unable to
understand the 4 components provided, the tuplet is considered ill-formed.
While a build system is free to resolve the validity of a target tuplet, only a
compiler can verify whether or not it is well formed.</p>
   <p><sup>6</sup> In addition to the requirements above, a compiler or build system
is free to take fewer than the 4 components required of a target tuplet. Such a
sequence is called a <em>supplied target tuplet</em>. Each missing component in a
supplied target tuplet can be replaced with the catch-all name <code class="highlight"><c- n>unknown</c-></code>,
however at least one component must be supplied by name.
[<em>Note:</em> In most cases, the <code class="highlight"><c- n>vendor</c-></code> component will be ignored or missing —<wbr><em>end note</em>]</p>
   <h3 class="heading settled" data-level="4.3" id="component-descriptions"><span class="secno">4.3. </span><span class="content">Component Descriptions</span><a class="self-link" href="#component-descriptions"></a></h3>
   <h4 class="heading settled" data-level="4.3.1" id="component-architecture"><span class="secno">4.3.1. </span><span class="content">Architecture</span><a class="self-link" href="#component-architecture"></a></h4>
   <p><sup>1</sup> The architecture refers to the instruction set used for a given
processor.</p>
   <p><sup>2</sup> The architecture may not refer to specific releases of names of a
given processor.</p>
   <p><sup>3</sup> The architecture is permitted to express revisions to the
instruction set itself.</p>
   <p><sup>4</sup> [<em>Note:</em> <code class="highlight"><c- n>arm</c-></code>, <code class="highlight"><c- n>armv6</c-></code>, and <code class="highlight"><c- n>armv7a</c-></code> are from the same family of
processors, however the <code class="highlight"><c- n>v6</c-></code> and <code class="highlight"><c- n>v7</c-></code> refer to revisions made to the ISA —<wbr><em>end note</em>]</p>
   <h4 class="heading settled" data-level="4.3.2" id="component-vendor"><span class="secno">4.3.2. </span><span class="content">Vendor</span><a class="self-link" href="#component-vendor"></a></h4>
   <p><sup>1</sup> A vendor is any entity that provides a C++ toolchain to a user.
Whether this is an organization, a simple person, a PC, or even no one. <sup>2</sup> In the event that no one is marked as the vendor, the component
will always resolve to the value <code class="highlight"><c- n>none</c-></code>.</p>
   <h4 class="heading settled" data-level="4.3.3" id="component-operating-system"><span class="secno">4.3.3. </span><span class="content">Operating System</span><a class="self-link" href="#component-operating-system"></a></h4>
   <p><sup>1</sup> An <em>operating system</em> is a superset of an environment, but is
not responsible of how a user interacts with their toolchain.</p>
   <h4 class="heading settled" data-level="4.3.4" id="component-environment"><span class="secno">4.3.4. </span><span class="content">Environment</span><a class="self-link" href="#component-environment"></a></h4>
   <p>
    <sup>1</sup> An <em>environment</em> is any one of an executable file format, an 
    <abbrU0003DU00022application binary interfaceU00022>ABI or a runtime.</abbrU0003DU00022application>
   </p>
   <p><sup>2</sup> Due to the nature of how an environment can be expressed, each
type of environment can supercede another, with the exception of an executable
file format.</p>
   <dl>
    <dt data-md>
    <dd data-md>
     <p><sup>(2.1)</sup> An executable file format implies that there is only 1 way
 to load and execute the program without virtualizing or converting to another
 environment.</p>
    <dd data-md>
     <p><sup>(2.2)</sup> An ABI implies the existence of an executable file format,
 an object file format, and 1 or more calling conventions for symbols within
 the object file format</p>
    <dd data-md>
     <p><sup>(2.3)</sup> A runtime is an object file format, an ABI for object
 files, and 1 or more libraries needed for a an executable to be produced</p>
   </dl>
   <h4 class="heading settled" data-level="4.3.5" id="component-resolution"><span class="secno">4.3.5. </span><span class="content">Resolution</span><a class="self-link" href="#component-resolution"></a></h4>
   <p><sup>1</sup> Resolving a supplied target tuplet into a well-formed target
tuplet is not an intuitive process based on the written form.</p>
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   <p><sup>2</sup> While the written component order is currently <code class="highlight"><c- n>architecture</c-></code>, <code class="highlight"><c- n>vendor</c-></code>, <code class="highlight"><c- n>operating</c-> <c- n>system</c-></code>, and <code class="highlight"><c- n>environment</c-></code>, the actual priority differs
based on the importance of each component.</p>
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    <figcaption>Component Priority Order</figcaption>
   </figure>
   <p><sup>3</sup> In the event that no operating system was provided, the component
will be set to the <em>bare metal specifier</em> <code class="highlight"><c- n>none</c-></code> and the resolution steps are
to start again.</p>
   <h2 class="heading settled" data-level="5" id="explanation"><span class="secno">5. </span><span class="content">Informative Explanation</span><a class="self-link" href="#explanation"></a></h2>
   <p>The road to get to the point where we can have a definition of a target tuplet
has been a long one. There are many platforms, processors, toolchains, external
tools, build systems, and configurations to consider and many of these are
older than Standard C++ by almost a decade (The initial release of C++ in 1985
was during the beginning of very early stages of this "wild west" of cross
compilation). This section is intended to explain some of the decisions made
with wording, as well as some of the history of how we ended up at the point we
are currently at. Additionally, a lot of work was done to formalize some of the
wording and to "</p>
   <h3 class="heading settled" data-level="5.1" id="brief-history"><span class="secno">5.1. </span><span class="content">A Brief History of Compiler Targets</span><a class="self-link" href="#brief-history"></a></h3>
   <p>Many older compilers are no longer available. Their source code, binaries,
documentation, etc. are either lost to time, or require vast sums of money to
gain access to. As such, the author only had GCC, a few non-triplet configured
C compilers, and a handful of usenet postings to go off of for the information
located here.</p>
   <p class="note" role="note"><span>Note:</span> This portion of the document is not meant to be a "Howard Zinn-esque"
retelling of how target tuplets came to be.</p>
   <p>Before autotools, GCC’s early releases used simple shell scripts that were
written by hand. The changelog was only a small file with a few notes, and
some light information on how to configure the build for porting to new
platforms. These files were labelled <code class="highlight"><c- n>config</c-><c- o>-&lt;</c-><c- n>processor</c-><c- o>></c-></code>, as the ability to
target a specific toolchain wasn’t really a possibility at the time. As time
went on, the number of targets that GCC could run on or target grew. This is
when the first set of target triplets were created. At the time, the second
field of a triplet was what is now the <em>third entry</em> in a target tuplet. At
some point, an optional <em>vendor</em> field was created. In the wild, some might be
familiar with the "triplet" of <code class="highlight"><c- n>x86_64</c-><c- o>-</c-><c- n>none</c-><c- o>-</c-><c- n>linux</c-><c- o>-</c-><c- n>gnu</c-></code>, which is also sometimes
represented as <code class="highlight"><c- n>x86_64</c-><c- o>-</c-><c- n>unknown</c-><c- o>-</c-><c- n>linux</c-><c- o>-</c-><c- n>gnu</c-></code> or <code class="highlight"><c- n>x86_64</c-><c- o>-</c-><c- n>pc</c-><c- o>-</c-><c- n>linux</c-><c- o>-</c-><c- n>gnu</c-></code>. A list of
wildcard host/targets is <a data-link-type="biblio" href="#biblio-gcc-host-target">provided by GCC</a>.</p>
   <p>Because of the success of GCC, this form of targeting a platform became the <em>de
facto</em> way of defining a target. GCC also added several aliases over the years
(e.g., permitting <code class="highlight"><c- o>*-*-*-</c-><c- n>linux</c-></code> to mean <code class="highlight"><c- o>*-*-*-</c-><c- n>elf</c-></code> on some platforms), which
led to a bit of confusion on how to target a platform. Once Clang supported
targets, they did not provide aliases, which reduced the surface area for
confusion.</p>
   <h3 class="heading settled" data-level="5.2" id="vendor"><span class="secno">5.2. </span><span class="content">Why Vendor Over Machine</span><a class="self-link" href="#vendor"></a></h3>
   <p>At the Denver 2019-09 SG15 meeting, the author was recommended via a poll
result to investigate naming conventions for the second entry as to whether it
should be <em>vendor</em> or <em>machine</em>. After some time, it became clear that the <em>vendor</em> entry has always been for vendors. The use of <code class="highlight"><c- o>*-</c-><c- n>pc</c-><c- o>-*</c-></code> was taken
instead to mean "IBM Compatible PC", back when that used to mean something.</p>
   <p>However, when users have taken to think the second entry is a machine,
operating system, or platform, the compiler has effectively <em>normalized</em> the
second field to either be <code class="highlight"><c- n>unknown</c-></code> or something else. Thus, using <em>machine</em> does not work well, as the wording above states that <em>vendor</em> is optional in a <em>supplied target tuplet</em>.</p>
   <h3 class="heading settled" data-level="5.3" id="environment"><span class="secno">5.3. </span><span class="content">Why environment over X</span><a class="self-link" href="#environment"></a></h3>
   <p>Some other names came up during discussion of the fourth field. These included, <code class="highlight"><c- n>runtime</c-></code>, <code class="highlight"><c- n>ABI</c-></code>, etc. In actuality, this last field has historically been
where everything is thrown into one place to differentiate the compiler’s
target from effectively everything else. In practice, however, there is a
hierarchy implied by <em>what</em> is in this field.</p>
   <p>If an object file format, such as <code class="highlight"><c- n>PE</c-></code>, <code class="highlight"><c- n>COFF</c-></code>, <code class="highlight"><c- n>a</c-><c- p>.</c-><c- n>out</c-></code>, <code class="highlight"><c- n>Mach</c-><c- o>-</c-><c- n>O</c-></code>, or <code class="highlight"><c- n>ELF</c-></code> is
given, it typically implies that there are 0 or 1 default vendor specific ABI
or runtime available. In other words, these <em>could</em> be freestanding compiler
targets, or there is only one possible runtime provided by the compiler.  e.g.,
in the case of <code class="highlight"><c- o>*-</c-><c- n>apple</c-><c- o>-*-</c-><c- n>macho</c-></code>, there is only ONE ABI and runtime available,
and it is provided by Apple, with the object file format being <code class="highlight"><c- n>Mach</c-><c- o>-</c-><c- n>O</c-></code>. In the
case of a <code class="highlight"><c- o>*-</c-><c- n>apple</c-><c- o>-*-</c-><c- n>coff</c-></code>, there is still only ONE ABI and runtime available,
but the object file format is now different.</p>
   <p>A level above this, is an ABI. e.g., <code class="highlight"><c- n>gnu</c-></code>, or <code class="highlight"><c- n>msvc</c-></code>. These imply all of:</p>
   <ul>
    <li data-md>
     <p>an object file format (e.g., ELF and PE/COFF)</p>
    <li data-md>
     <p>1 or more calling conventions for symbols within the object file format</p>
    <li data-md>
     <p>multiple runtimes that can co-exist on a given platform.</p>
   </ul>
   <p>This is why, for the uninformed, MinGW and MSVC cannot link against each other
unless it is done via C and unless the "symbols" agree upon calling convention.</p>
   <p>Above this, we have <em>runtimes</em>. These have all of:</p>
   <ul>
    <li data-md>
     <p>A specific object file format</p>
    <li data-md>
     <p>An ABI for storing precompiled object file formats</p>
    <li data-md>
     <p>1 or more libraries needed for a program to load without issue.</p>
   </ul>
   <p>As an example, <code class="highlight"><c- n>mingw</c-></code> generates object files under the PE/COFF format,
supports both the <code class="highlight"><c- kr>__stdcall</c-></code> and <code class="highlight"><c- kr>__cdecl</c-></code> calling conventions, and supplies
a runtime that allows GCC compiled code to run directly on Windows. While the
actual format of the PE/COFF files generated by MinGW are not compatible with
MSVC, this doesn’t change that MinGW has its own runtime, even if said runtime
is simply to reorganize symbols so that it can safely link against the MSVC
runtime.</p>
   <p>Likewise, <code class="highlight"><c- n>cygwin</c-></code> generates object files under the PE/COFF format, but targets
a POSIX-like environment. Thus it requires a library for its generated programs
to execute correctly.</p>
   <p>Because of this tiered system, an "umbrella" term is needed. Our toolchains do
not exist in a vacuum, and interact with our overall <em>environment</em>, hence the
name <em>environment</em> was chosen.</p>
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  var autoToggle   = function(e){ toggleSidebar(e.matches) };
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    sidebarMedia.addListener(autoToggle);
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  function toggleSidebar(on) {
    if (on == undefined) {
      on = !document.body.classList.contains('toc-sidebar');
    }

    /* Don’t scroll to compensate for the ToC if we’re above it already. */
    var headY = 0;
    var head = document.querySelector('.head');
    if (head) {
      // terrible approx of "top of ToC"
      headY += head.offsetTop + head.offsetHeight;
    }
    var skipScroll = window.scrollY < headY;

    var toggle = document.getElementById('toc-toggle');
    var tocNav = document.getElementById('toc');
    if (on) {
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      document.body.classList.add('toc-sidebar');
      document.body.classList.remove('toc-inline');
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      tocNav.focus();
      sidebarMedia.addListener(autoToggle); // auto-collapse when out of room
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    else {
      document.body.classList.add('toc-inline');
      document.body.classList.remove('toc-sidebar');
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      if (!skipScroll) {
        window.scrollBy(0, tocNav.offsetHeight);
      }
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           because I don’t know where else to send the focus. */
        toggle.blur();
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    }
  }

  function createSidebarToggle() {
    /* Create the sidebar toggle in JS; it shouldn’t exist when JS is off. */
    var toggle = document.createElement('a');
      /* This should probably be a button, but appearance isn’t standards-track.*/
    toggle.id = 'toc-toggle';
    toggle.class = 'toc-toggle';
    toggle.href = '#toc';
    toggle.innerHTML = collapseSidebarText;

    sidebarMedia.addListener(autoToggle);
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      toggleSidebar();
      return false;
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    toggle.addEventListener('click', toggler, false);


    /* Get <nav id=toc-nav>, or make it if we don’t have one. */
    var tocNav = document.getElementById('toc-nav');
    if (!tocNav) {
      tocNav = document.createElement('p');
      tocNav.id = 'toc-nav';
      /* Prepend for better keyboard navigation */
      document.body.insertBefore(tocNav, document.body.firstChild);
    }
    /* While we’re at it, make sure we have a Jump to Toc link. */
    var tocJump = document.getElementById('toc-jump');
    if (!tocJump) {
      tocJump = document.createElement('a');
      tocJump.id = 'toc-jump';
      tocJump.href = '#toc';
      tocJump.innerHTML = tocJumpText;
      tocNav.appendChild(tocJump);
    }

    tocNav.appendChild(toggle);
  }

  var toc = document.getElementById('toc');
  if (toc) {
    createSidebarToggle();
    toggleSidebar(sidebarMedia.matches);

    /* If the sidebar has been manually opened and is currently overlaying the text
       (window too small for the MQ to add the margin to body),
       then auto-close the sidebar once you click on something in there. */
    toc.addEventListener('click', function(e) {
      if(e.target.tagName.toLowerCase() == "a" && document.body.classList.contains('toc-sidebar') && !sidebarMedia.matches) {
        toggleSidebar(false);
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    }, false);
  }
  else {
    console.warn("Can’t find Table of Contents. Please use <nav id='toc'> around the ToC.");
  }

  /* Wrap tables in case they overflow */
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  var numTables = tables.length;
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    var table = tables[i];
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</script>
  <h2 class="no-num no-ref heading settled" id="references"><span class="content">References</span><a class="self-link" href="#references"></a></h2>
  <h3 class="no-num no-ref heading settled" id="informative"><span class="content">Informative References</span><a class="self-link" href="#informative"></a></h3>
  <dl>
   <dt id="biblio-clang-cross-compile">[CLANG-CROSS-COMPILE]
   <dd><a href="https://clang.llvm.org/docs/CrossCompilation.html">Cross-compilation using Clang</a>. URL: <a href="https://clang.llvm.org/docs/CrossCompilation.html">https://clang.llvm.org/docs/CrossCompilation.html</a>
   <dt id="biblio-gcc-host-target">[GCC-HOST-TARGET]
   <dd><a href="https://gcc.gnu.org/install/specific.html">Host/Target specific installation notes for GCC</a>. URL: <a href="https://gcc.gnu.org/install/specific.html">https://gcc.gnu.org/install/specific.html</a>
  </dl>