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  <title>P1378R0: std::string_literal</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">P1378R0<br>std::string_literal</h1>
   <h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Published Proposal, <time class="dt-updated" datetime="2018-11-26">2018-11-26</time></span></h2>
   <div data-fill-with="spec-metadata">
    <dl>
     <dt>Author:
     <dd>
      <dd class="editor p-author h-card vcard"><a class="p-name fn u-email email" href="mailto:phdofthehouse@gmail.com">JeanHeyd Meneide</a>
     <dt>Audience:
     <dd>SG16
     <dt>Project:
     <dd>ISO/IEC JTC1/SC22/WG21 14882: Programming Language — C++
     <dt>Latest:
     <dd><a href="https://thephd.github.io/vendor/future_cxx/papers/d1378.html">https://thephd.github.io/vendor/future_cxx/papers/d1378.html</a>
    </dl>
   </div>
   <div data-fill-with="warning"></div>
   <hr title="Separator for header">
  </div>
  <div class="p-summary" data-fill-with="abstract">
   <h2 class="no-num no-toc no-ref heading settled" id="abstract"><span class="content">Abstract</span></h2>
   <p>This paper proposes a new type <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>></c-></code> that represents and captures only string literals.</p>
  </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="#changelog-r1"><span class="secno">1.1</span> <span class="content">Revision 0 - November 26th, 2018</span></a>
     </ol>
    <li><a href="#motivation"><span class="secno">2</span> <span class="content">Motivation</span></a>
    <li>
     <a href="#design"><span class="secno">3</span> <span class="content">Design</span></a>
     <ol class="toc">
      <li><a href="#design-nts"><span class="secno">3.1</span> <span class="content">Safe to convert to NTS</span></a>
      <li><a href="#design-compat"><span class="secno">3.2</span> <span class="content">Backwards Compatibility</span></a>
      <li><a href="#design-conversions"><span class="secno">3.3</span> <span class="content">Conversion Rankings</span></a>
     </ol>
    <li>
     <a href="#wording"><span class="secno">4</span> <span class="content">Proposed Wording</span></a>
     <ol class="toc">
      <li><a href="#wording-feature"><span class="secno">4.1</span> <span class="content">Feature Test Macro</span></a>
      <li><a href="#wording-intent"><span class="secno">4.2</span> <span class="content">Intent</span></a>
      <li><a href="#wording-core-library"><span class="secno">4.3</span> <span class="content">Proposed Wording</span></a>
     </ol>
    <li><a href="#acknowledgements"><span class="secno">5</span> <span class="content">Acknowledgements</span></a>
    <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="changelog-r1"><span class="secno">1.1. </span><span class="content">Revision 0 - November 26th, 2018</span><a class="self-link" href="#changelog-r1"></a></h3>
   <ul>
    <li data-md>
     <p>Initial release.</p>
   </ul>
   <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>This sort of feature has seen many previous iterations, albeit their motivations were only tangentially related. <a data-link-type="biblio" href="#biblio-p0424">[p0424]</a> and <a data-link-type="biblio" href="#biblio-p0732">[p0732]</a> all attempted to create a form of this for various different reasons, from better UDL handling to a proper string type with a fixed backing storage for non-type template parameters. Early forms of this proposal, such as <a data-link-type="biblio" href="#biblio-p0259">[p0259]</a>, also focused on making string-like behaviors available for <code class="highlight"><c- k>constexpr</c-></code> programming, but were superseded by the previous proposal. Ongoing work has been dedicated to making <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>string</c-></code> fully constexpr to allow for its usage in more complicated syntaxes.</p>
   <p>It is clear that <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>string</c-></code> and <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>string_view</c-></code> are going to be and already are fully <code class="highlight"><c- k>constexpr</c-></code>, respectively. This still does not solve the inherent problem that has been run into recently, which is knowing that an argument provided is indeed a string literal. In particular, <a data-link-type="biblio" href="#biblio-p1040">[p1040]</a> was discussed in the San Diego 2018 ISO C++ Standards Meeting. The primary problem identified was with that of tooling: because a resource identifier could be computed at constexpr time and passed as the argument to <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>embed</c-></code>, then having a proper association between a <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>embed</c-></code> resource and the object file result is hard to communicate to the user or build system without performing full semantic analysis. Many suggestions were given, but it became apparently that all of the solutions relied on the crux of one common realization: the string for embedded a file can be computed at <code class="highlight"><c- k>constexpr</c-></code> time, which makes it impossible to extract resource identifier dependency information pre-Phase 7 of compilation.</p>
   <p>Since, full semantic analysis must be run before the compiler can be sure of the value passed to <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>embed</c-></code>, it becomes impossible to list the file as an explicit dependency in the graphs exported by compiler options such as <code class="highlight"><c- o>-</c-><c- n>MMD</c-></code>, which only have to perform preprocessing and some basic amount of lexical analysis. It would be better if we could properly express simple dependencies that can participate in the build system without explicitly listing it by ensuring that the value passed to <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>embed</c-></code> is a string literal.</p>
   <p>More broadly, the goal of this type is to solve 2 key use cases. The first is that some functions are increasingly interested in the source of some string data, especially when it comes to strings. Functions that take <code class="highlight"><c- k>const</c-> <c- n>CharType</c-><c- p>[</c-><c- n>N</c-><c- p>]</c-></code> are inherently losing information from the user: usages of string literals as arrays are lossy transformations that deprive interested parties in necessary source information. For example, is the array backed by compiler-created storage, or did the user create one themselves? Is it null-terminated, or not? We have absolutely no guarantees right now, and that is frustrating to most programmers who care.</p>
   <p>Secondly, we care if our tools are able to know the value without having to perform full semantic analysis. A <code class="highlight"><c- k>constexpr</c-></code> <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>string_view</c-></code> or <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>string</c-></code> do not buy us this guarantee: they can be fully composed at semantic analysis time when the <code class="highlight"><c- k>constexpr</c-></code>-evaluator runs, generating things that the compiler cannot track until during/after Phase 7 of compilation. This is too late for tools to know the value without significantly slowing down dependency graph generation and other useful compiler services to the build system.</p>
   <p>We propose a type that can only be constructed with a non-empty value by the compiler for all the string literal types (<code class="highlight"><c- b>char</c-></code>, <code class="highlight"><c- b>wchar_t</c-></code>, <code class="highlight"><c- b>char16_t</c-></code>, <code class="highlight"><c- b>char32_t</c-></code>, and <code class="highlight"><c- n>char8_t</c-></code>). Objects of this type can be captured by application and library developers as the type <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>></c-></code>.</p>
   <h2 class="heading settled" data-level="3" id="design"><span class="secno">3. </span><span class="content">Design</span><a class="self-link" href="#design"></a></h2>
   <p>This type can implicitly decay to a <code class="highlight"><c- k>const</c-></code> lvalue reference to an array of <code class="highlight"><c- k>const</c-> <c- n>CharType</c-></code>. It can be default-constructed and will represent an empty null-terminated (byte) string (NT(B)S), which will be a <code class="highlight"><c- k>const</c-> <c- n>CharType</c-><c- p>[</c-><c- mi>1</c-><c- p>]</c-></code>. As a NTS, the size of the underlying array will is guaranteed to be 1 or more and <code class="highlight"><c- o>*</c-><c- n>std</c-><c- o>::</c-><c- n>end</c-><c- p>(</c-><c- s>""</c-><c- p>)</c-></code> will always be valid and equal to <code class="highlight"><c- sc>'\0'</c-></code> as it is today. The result of a <code class="highlight"><c- s>"asdf"</c-></code> or similar string literal will always be a <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>></c-></code>:</p>
<pre class="highlight"><c- cp>#include</c-> &lt;type_traits>
<c- cp>#include</c-> &lt;string_literal>

<c- b>int</c-> <c- nf>main</c-> <c- p>()</c-> <c- p>{</c->
	<c- k>auto</c-> <c- n>x</c-> <c- o>=</c-> <c- s>"woof"</c-><c- p>;</c->
	<c- k>const</c-> <c- k>auto</c-><c- o>&amp;</c-> <c- n>x_ref</c-> <c- o>=</c-> <c- s>"purr"</c-><c- p>;</c->
	<c- k>static_assert</c-><c- p>(</c-><c- n>std</c-><c- o>::</c-><c- n>is_same_v</c-><c- o>&lt;</c-><c- n>std</c-><c- o>::</c-><c- n>string_literal</c-><c- o>&lt;</c-><c- mi>5</c-><c- o>></c-><c- p>,</c-> <c- k>decltype</c-><c- p>(</c-><c- n>x</c-><c- p>)</c-><c- o>></c-><c- p>);</c->
	<c- k>static_assert</c-><c- p>(</c-><c- n>std</c-><c- o>::</c-><c- n>is_same_v</c-><c- o>&lt;</c-><c- n>std</c-><c- o>::</c-><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- b>char</c-><c- p>,</c-> <c- mi>5</c-><c- o>></c-><c- p>,</c-> <c- k>decltype</c-><c- p>(</c-><c- n>x</c-><c- p>)</c-><c- o>></c-><c- p>);</c->
	<c- k>static_assert</c-><c- p>(</c-><c- n>std</c-><c- o>::</c-><c- n>is_same_v</c-><c- o>&lt;</c-><c- k>const</c-> <c- n>std</c-><c- o>::</c-><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- mi>5</c-><c- o>>&amp;</c-><c- p>,</c-> <c- k>decltype</c-><c- p>(</c-><c- n>x_ref</c-><c- p>)</c-><c- o>></c-><c- p>);</c->

	<c- k>return</c-> <c- mi>0</c-><c- p>;</c->
<c- p>}</c->
</pre>
   <h3 class="heading settled" data-level="3.1" id="design-nts"><span class="secno">3.1. </span><span class="content">Safe to convert to NTS</span><a class="self-link" href="#design-nts"></a></h3>
   <p>This type avoids the problems of knowing whether a character array or a <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>basic_string_view</c-><c- o>&lt;</c-><c- n>CharType</c-><c- o>></c-></code> is a real NTS. This means that rather than having to run <code class="highlight"><c- n>strlen</c-></code> on the input functions can take the size and immediately know the string has a null terminator at the end. Running afoul of potentially embedded nulls or running off the end of an user-declared array that forgets to null-terminate its storage need not be a concern. APIs transition from accepting the blunt type which does not preserve any source information (e.g. <code class="highlight"><c- k>const</c-> <c- b>char</c-><c- p>[</c-><c- mi>20</c-><c- p>]</c-></code>) to a type that preserves source information and gives up guarantees (e.g. <code class="highlight"><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- b>char</c-><c- p>,</c-> <c- mi>20</c-><c- o>></c-></code>). We can also declare an API that properly handles string literals without decaying to pointers. This can also provide code size and performance benefits, as demonstrated in <a href="https://youtu.be/sSlmmZMFsXQ?t=4814">Jason Turner’s C++Now 2018 talk on initializer_list with various different string types</a> and their interaction with types like <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>string</c-></code> vs. <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>string_view</c-></code> vs. <code class="highlight"><c- k>const</c-> <c- b>char</c-><c- o>*</c-></code> vs. <code class="highlight"><c- k>const</c-> <c- b>char</c-><c- p>(</c-><c- o>&amp;</c-><c- p>)[</c-><c- n>N</c-><c- p>]</c-></code>.</p>
   <p>Another big problem with using purely <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>basic_string_view</c-><c- o>&lt;</c-><c- n>CharType</c-><c- o>></c-></code> and/or <code class="highlight"><c- k>const</c-> <c- n>CharType</c-><c- p>(</c-><c- o>&amp;</c-><c- p>)[</c-><c- n>N</c-><c- p>]</c-></code> is the lack of a guarantee about what memory is being referred to by the time it is received in e.g. a function call. Is it truly read-only memory? Did the user initialize an array on the stack that is backing this type? There are so many questions and there is no way to retrieve the answer properly. With this type, we know for sure that the string literal is stored in constant memory that cannot be modified and is null-terminated.</p>
   <h3 class="heading settled" data-level="3.2" id="design-compat"><span class="secno">3.2. </span><span class="content">Backwards Compatibility</span><a class="self-link" href="#design-compat"></a></h3>
   <p>It is imperative that this type does not break the assumptions that come from existing code. Because of the implicit conversion to an array on this type, operations such as indexing, arithmetic from the decay-to-pointer, and other properties of the original array type are preserved:</p>
<pre class="highlight"><c- c1>// used to be const char[5], </c->
<c- c1>// now is std::basic_string_literal&lt;char, 5></c->
<c- c1>// NOTE: CTAD (with p1021, approved in San Diego) </c->
<c- c1>// allows us to leave off char/N specifiers in the type name</c->
<c- n>std</c-><c- o>::</c-><c- n>string_literal</c-> <c- n>x</c-> <c- o>=</c-> <c- s>"bark"</c-><c- p>;</c-> 
<c- c1>// okay: conversion, decay</c->
<c- k>const</c-> <c- b>char</c-><c- o>*</c-> <c- n>first</c-> <c- o>=</c-> <c- n>x</c-><c- p>;</c->
<c- c1>// okay: conversion, decay, then addition</c->
<c- k>const</c-> <c- b>char</c-><c- o>*</c-> <c- n>last</c-> <c- o>=</c-> <c- n>x</c-> <c- o>+</c-> <c- mi>5</c-><c- p>;</c->
<c- c1>// okay: conversion, then indexing operation</c->
<c- b>char</c-> <c- n>letter_a</c-> <c- o>=</c-> <c- n>x</c-><c- p>[</c-><c- mi>1</c-><c- p>];</c->
<c- c1>// okay: conversion, then indexing operation</c->
<c- k>auto</c-> <c- n>letter_a</c-> <c- o>=</c-> <c- n>x</c-><c- p>[</c-><c- mi>1</c-><c- p>];</c->
</pre>
   <p>(To see how the CTAD might work in a pre-p1021 (C++17) world, see the stub example working on <a href="http://coliru.stacked-crooked.com/a/ce2da1bd3251a85b">Coliru</a> and <a href="https://gcc.godbolt.org/z/Vb-Ccd">Compiler Explorer</a>)</p>
   <p>The one place where this might provide a breaking change is for users who take the address of a string literal using <code class="highlight"><c- o>&amp;</c-><c- s>"arf"</c-></code>. Because the type has changed, this operation may not do what it is expected of code that may have had to use this operation. Currently, the wording synopsis for <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>></c-></code> below does not provide an <code class="highlight"><c- k>operator</c-><c- o>&amp;</c-></code>; chiefly, taking the address of a literal directly is an exceedingly rare use case, even for generic code. The author encourages individuals to voice any concerns they have while this potential breakage is considered. If this is deemed a significant use case for strings, then this paper will add the overloaded <code class="highlight"><c- k>operator</c-><c- o>&amp;</c-></code> to assuage those compatibility concerns.</p>
   <p>There is also little concern about ABI. The <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>basic_string_literal</c-></code> type is meant to be binary-compatible with a regular built-in array, the same way <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>array</c-></code> is. Because the type never existed before, name mangling is only a problem for individuals who took built-in arrays as parameters or returned them as values that they expected to be strings with <code class="highlight"><c- k>decltype</c-><c- p>(</c-><c- k>auto</c-><c- p>)</c-></code>. It seems incredibly unlikely that an interface which returns an array by reference through use of <code class="highlight"><c- k>decltype</c-><c- p>(</c-><c- k>auto</c-><c- p>)</c-></code> exists and is in prevalent use with C++ compiled at ABI boundaries.</p>
   <h3 class="heading settled" data-level="3.3" id="design-conversions"><span class="secno">3.3. </span><span class="content">Conversion Rankings</span><a class="self-link" href="#design-conversions"></a></h3>
   <p>One of the biggest problems is that the moment someone looks at an array even the tiniest bit funny, it converts down to a pointer to its first element. This has long caused issues of overload resolution (and more issues of people confusing pointers to represent arrays, though this proposal does not solve that unfortunate association). By making it so the type of all string literals are <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>></c-></code>, this proposal ensures that users can catch the string literal type before the resulting conversion to <code class="highlight"><c- k>const</c-> <c- n>CharType</c-><c- p>[</c-><c- n>N</c-><c- p>]</c-></code> and the subsequent conversions to <code class="highlight"><c- k>const</c-> <c- n>CharType</c-><c- o>*</c-></code>. Note that, unlike user-defined conversions, built-in conversions are allowed to happen an infinite number of times (as compared to user-defined conversions, of which there may only be one on the way to the final destination type). This means that converting to a built-in array allows the regular pointer conversions to happen naturally afterwards, while providing unambiguous overload resolution:</p>
<pre class="highlight"><c- cp>#include</c-> &lt;string_literal>

<c- k>template</c-> <c- o>&lt;</c-><c- b>size_t</c-> <c- n>N</c-><c- o>></c->
<c- b>void</c-> <c- n>f</c-><c- p>(</c-> <c- k>const</c-> <c- n>std</c-><c- o>::</c-><c- n>string_literal</c-><c- o>&lt;</c-><c- n>N</c-><c- o>>&amp;</c-> <c- n>lit</c-> <c- p>)</c-> <c- p>{</c->
    <c- c1>// 1</c->
<c- p>}</c->

<c- k>template</c-> <c- o>&lt;</c-><c- b>size_t</c-> <c- n>N</c-><c- o>></c->
<c- b>void</c-> <c- n>f</c-><c- p>(</c-> <c- k>const</c-> <c- b>char</c-><c- p>(</c-><c- o>&amp;</c-> <c- n>arr</c-><c- p>)[</c-><c- n>N</c-><c- p>]</c-> <c- p>)</c-> <c- p>{</c->
    <c- c1>// 2</c->
<c- p>}</c->

<c- b>void</c-> <c- n>f</c-><c- p>(</c-> <c- k>const</c-> <c- b>char</c-><c- o>*</c-> <c- n>ptr</c-><c- p>)</c-> <c- p>{</c->
    <c- c1>// 3</c->
<c- p>}</c->

<c- b>int</c-> <c- n>main</c-> <c- p>()</c-> <c- p>{</c->
	<c- k>const</c-> <c- b>char</c-> <c- n>arr</c-><c- p>[</c-><c- mi>2</c-><c- p>]{};</c->
	<c- k>const</c-> <c- b>char</c-><c- o>*</c-> <c- n>ptr</c-> <c- o>=</c-> <c- n>arr</c-><c- p>;</c->
	<c- n>f</c-><c- p>(</c-><c- s>""</c-><c- p>);</c-> <c- c1>// picks 1, unambiguously</c->
	<c- n>f</c-><c- p>(</c-><c- n>arr</c-><c- p>);</c-> <c- c1>// picks 2, unambiguously</c->
	<c- n>f</c-><c- p>(</c-><c- n>ptr</c-><c- p>);</c-> <c- c1>// picks 3, unambiguously</c->
	<c- k>return</c-> <c- mi>0</c-><c- p>;</c->
<c- p>}</c->
</pre>
   <h2 class="heading settled" data-level="4" id="wording"><span class="secno">4. </span><span class="content">Proposed Wording</span><a class="self-link" href="#wording"></a></h2>
   <p><strong>Help for wording (especially core) would be appreciated!</strong> All wording is relative to <a data-link-type="biblio" href="#biblio-n4762">[n4762]</a>-ish (for example, this anticipates <code class="highlight"><c- n>char8_t</c-></code> changes being applied that were approved in San Diego).</p>
   <h3 class="heading settled" data-level="4.1" id="wording-feature"><span class="secno">4.1. </span><span class="content">Feature Test Macro</span><a class="self-link" href="#wording-feature"></a></h3>
   <p>The desire feature test macro for the language change is <code class="highlight"><c- n>__cpp_impl_string_literal</c-></code>. The desired feature test macro for the library change is <code class="highlight"><c- n>__cpp_lib_string_literal</c-></code>.</p>
   <h3 class="heading settled" data-level="4.2" id="wording-intent"><span class="secno">4.2. </span><span class="content">Intent</span><a class="self-link" href="#wording-intent"></a></h3>
   <p>The intent of this wording is to supply the following:</p>
   <ul>
    <li data-md>
     <p>Create a new type <code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>></c-></code>.</p>
     <ul>
      <li data-md>
       <p>The type shall implicitly convert to an array of <code class="highlight"><c- k>const</c-></code> <code class="highlight"><c- n>CharType</c-></code>.</p>
      <li data-md>
       <p>The type shall work with ranged for loops.</p>
      <li data-md>
       <p>The type will copy its underlying storage when copied.</p>
      <li data-md>
       <p>The type’s interface will be entirely read-only / "morally <code class="highlight"><c- k>const</c-></code>".</p>
      <li data-md>
       <p>The type shall be generated only by the core language (except for when default constructed).</p>
     </ul>
    <li data-md>
     <p>String literals in C++ are now of this type, and they convert to <code class="highlight"><c- k>const</c-> <c- n>CharType</c-><c- p>(</c-><c- o>&amp;</c-><c- p>)[</c-><c- n>N</c-><c- p>]</c-></code> implicitly.</p>
     <ul>
      <li data-md>
       <p>They can still be used to initialize character arrays: <a href="http://eel.is/c++draft/dcl.init.string">§9.3.2 (dcl.init.string)</a> remains unchanged.</p>
     </ul>
    <li data-md>
     <p>It shall not prohibit implementations from storing the data in constant memory as implementations have always done.</p>
    <li data-md>
     <p>Supply a feature test macro that indicates the core language will generate such a type, <code class="highlight"><c- n>_cpp_impl_string_literals</c-></code>.</p>
    <li data-md>
     <p>Supply a feature test macro for the library that provides the type itself, <code class="highlight"><c- n>_cpp_lib_string_literals</c-></code>.</p>
   </ul>
   <h3 class="heading settled" data-level="4.3" id="wording-core-library"><span class="secno">4.3. </span><span class="content">Proposed Wording</span><a class="self-link" href="#wording-core-library"></a></h3>
   <p>Modify §5.13.5 [<strong>lex.string</strong>], clauses 6, 7, 10, 11, and 12 to change the type:</p>
   <blockquote>
     <sup>6</sup> After translation phase 6, a string-literal that does not begin with an encoding-prefix is an ordinary string literal. An ordinary string literal has type 
    <del>"array of n const char"</del>
    <ins><code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>string_literal</c-><c- o>&lt;</c-><c- n>n</c-><c- o>></c-></code> (16.� [<strong>support.stringlit</strong>])</ins>
     where <code class="highlight"><c- n>n</c-></code> is the size of the string as defined below, has static storage duration (6.6.4), and is initialized with the given characters. 
   </blockquote>
   <blockquote>
     <sup>7</sup> A string-literal that begins with <code class="highlight"><c- n>u8</c-></code>, such as <code class="highlight">u8<c- s>"asdf"</c-></code>, is a UTF-8 string literal, also referred to as a char8_t string literal. A char8_t string literal has type 
    <del>"array of n const char8_t"</del>
    <ins><code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>u8string_literal</c-><c- o>&lt;</c-><c- n>n</c-><c- o>></c-></code> (16.� [<strong>support.stringlit</strong>])</ins>
    , where n is the size of the string as defined below; each successive element of the object representation (6.7) has the value of the corresponding code unit of the UTF-8 encoding of the string. 
   </blockquote>
   <blockquote>
     <sup>10</sup> A string-literal that begins with <code class="highlight"><c- n>u</c-></code>, such as <code class="highlight">u<c- s>"asdf"</c-></code>, is a char16_t string literal. A char16_t string literal has type 
    <del>“array of n const char16_t”</del>
    <ins><code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>u16string_literal</c-><c- o>&lt;</c-><c- n>n</c-><c- o>></c-></code> (16.� [<strong>support.stringlit</strong>])</ins>
    , where <i>n</i> is the size of the string as defined below; it is initialized with the given characters. A single c-char may produce more than one char16_t character in the form of surrogate pairs. 
   </blockquote>
   <blockquote>
     <sup>11</sup> A string-literal that begins with U, such as <code class="highlight">U<c- s>"asdf"</c-></code>, is a char32_t string literal. A char32_t string literal has type 
    <del>“array of n const char32_t”</del>
    <ins><code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>u32string_literal</c-><c- o>&lt;</c-><c- n>n</c-><c- o>></c-></code> (16.� [<strong>support.stringlit</strong>])</ins>
    , where <i>n</i> is the size of the string as defined below; it is initialized with the given characters. 
   </blockquote>
   <blockquote>
     <sup>12</sup> A string-literal that begins with <code class="highlight"><c- n>L</c-></code>, such as <code class="highlight">L<c- s>"asdf"</c-></code>, is a wide string literal. A wide string literal has type 
    <del>“array of n const wchar_t”</del>
    <ins><code class="highlight"><c- n>std</c-><c- o>::</c-><c- n>wstring_literal</c-><c- o>&lt;</c-><c- n>n</c-><c- o>></c-></code> (16.� [<strong>support.stringlit</strong>])</ins>
    , where <i>n</i> is the size of the string as defined below; it is initialized with the given characters. 
   </blockquote>
   <p>Append to §14.8.1 Predefined macro names [<strong>cpp.predefined</strong>]'s <strong>Table 16</strong> with one additional entry:</p>
   <blockquote>
    <table>
     <tbody>
      <tr>
       <th>Macro name
       <th>Value
      <tr>
       <td>
        <ins>__cpp_impl_string_literals</ins>
       <td>
        <ins>201902L</ins>
    </table>
   </blockquote>
   <p>Append to §16.3.1 General [<strong>support.limits.general</strong>]'s <strong>Table 35</strong> one additional entry:</p>
   <blockquote>
    <table>
     <tbody>
      <tr>
       <th>Macro name
       <th>Value
      <tr>
       <td>
        <ins>__cpp_lib_string_literals</ins>
       <td>
        <ins>201902L</ins>
    </table>
   </blockquote>
   <p>Add an entry to §16.1 General [<strong>support.general</strong>] as follows:</p>
   <blockquote>
    <table>
     <tbody>
      <tr>
       <th>
       <th>Subclause
       <th>Header(s)
      <tr>
       <td>16.�
       <td>
        <ins>String Literals</ins>
       <td>
        <ins>&lt;string_literal></ins>
    </table>
   </blockquote>
   <p>Add a new section §16.� [<strong>support.stringlit</strong>]:</p>
   <blockquote>
    <ins><b>16.� String Literals <span style="float: right;">[<strong>support.stringlit</strong>]</span></b></ins>
    <p>
     <ins>The header <code class="highlight"><c- o>&lt;</c-><c- n>string_literal</c-><c- o>></c-></code> defines a class template and several support functions related to string literals (<a href="http://eel.is/c++draft/lex.string">5.13.5 [<strong>lex.string</strong>]</a>). All functions specified in this sub-clause are signal-safe (<a href="http://eel.is/c++draft/support.signal">16.12.4 [<strong>support.signal</strong>]</a>).</ins>
    </p>
    <ins><b>16.�.1 Header <code class="highlight"><c- o>&lt;</c-><c- n>string_literal</c-><c- o>></c-></code> synopsis <span style="float: right;">[<strong>stringlit.syn</strong>]</span></b></ins>
    <ins>
<pre class="highlight"><code class="highlight"><c- k><c- k>namespace</c-></c-> <c- n><c- n>std</c-></c-> <c- p><c- p>{</c-></c->
  <c- k><c- k>template</c-></c-> <c- o><c- o>&lt;</c-></c-><c- k><c- k>class</c-></c-> <c- nc><c- nc>CharType</c-></c-><c- p><c- p>,</c-></c-> <c- n><c- n>std</c-></c-><c- o><c- o>::</c-></c-><c- b><c- b>size_t</c-></c-> <c- n><c- n>N</c-></c-><c- o><c- o>></c-></c-> 
  <c- k><c- k>class</c-></c-> <c- nc><c- nc>basic_string_literal</c-></c-> <c- p><c- p>{</c-></c->
  <c- k><c- k>private</c-></c-><c- o><c- o>:</c-></c->
    <c- k><c- k>using</c-></c-> <c- n><c- n>storage_type</c-></c->      <c- o><c- o>=</c-></c-> <c- n><c- n>CharType</c-></c-><c- p><c- p>[</c-></c-><c- n><c- n>N</c-></c-><c- p><c- p>];</c-></c-> <c- c1><c- c1>// exposition-only</c-></c->
  <c- k><c- k>public</c-></c-><c- o><c- o>:</c-></c->
    <c- k><c- k>using</c-></c-> <c- n><c- n>value_type</c-></c->      <c- o><c- o>=</c-></c-> <c- n><c- n>CharType</c-></c-><c- p><c- p>;</c-></c->
    <c- k><c- k>using</c-></c-> <c- n><c- n>reference</c-></c->       <c- o><c- o>=</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- o><c- o>&amp;</c-></c-><c- p><c- p>;</c-></c->
    <c- k><c- k>using</c-></c-> <c- n><c- n>const_reference</c-></c-> <c- o><c- o>=</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- o><c- o>&amp;</c-></c-><c- p><c- p>;</c-></c->
    <c- k><c- k>using</c-></c-> <c- n><c- n>size_type</c-></c->       <c- o><c- o>=</c-></c-> <c- b><c- b>size_t</c-></c-><c- p><c- p>;</c-></c->

    <c- k><c- k>using</c-></c-> <c- n><c- n>iterator</c-></c->       <c- o><c- o>=</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- o><c- o>*</c-></c-><c- p><c- p>;</c-></c->
    <c- k><c- k>using</c-></c-> <c- n><c- n>const_iterator</c-></c-> <c- o><c- o>=</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- o><c- o>*</c-></c-><c- p><c- p>;</c-></c->
		
    <i><c- c1><c- c1>// 16.�.2, String literal constructor</c-></c-></i>
    <c- k><c- k>constexpr</c-></c-> <c- nf><c- nf>basic_string_literal</c-></c-><c- p><c- p>()</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->

    <i><c- c1><c- c1>// 16.�.3, String literal conversions</c-></c-></i>
    <c- k><c- k>constexpr</c-></c-> <c- k><c- k>operator</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>storage_type</c-></c-><c- o><c- o>&amp;</c-></c-> <c- p><c- p>()</c-></c-> <c- k><c- k>const</c-></c-><c- p><c- p>;</c-></c->

    <i><c- c1><c- c1>// 16.�.4, String literal access</c-></c-></i>
    <c- k><c- k>constexpr</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- o><c- o>*</c-></c-> <c- nf><c- nf>data</c-></c-><c- p><c- p>()</c-></c-> <c- k><c- k>const</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->
    <c- k><c- k>constexpr</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- o><c- o>*</c-></c-> <c- nf><c- nf>c_str</c-></c-><c- p><c- p>()</c-></c-> <c- k><c- k>const</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->

    <c- k><c- k>constexpr</c-></c-> <c- n><c- n>size_type</c-></c-> <c- nf><c- nf>size</c-></c-><c- p><c- p>()</c-></c-> <c- k><c- k>const</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->

    <c- k><c- k>constexpr</c-></c-> <c- n><c- n>iterator</c-></c-> <c- nf><c- nf>begin</c-></c-><c- p><c- p>()</c-></c-> <c- k><c- k>const</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->
    <c- k><c- k>constexpr</c-></c-> <c- n><c- n>iterator</c-></c-> <c- nf><c- nf>end</c-></c-><c- p><c- p>()</c-></c-> <c- k><c- k>const</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->
    <c- k><c- k>constexpr</c-></c-> <c- n><c- n>const_iterator</c-></c-> <c- nf><c- nf>cbegin</c-></c-><c- p><c- p>()</c-></c-> <c- k><c- k>const</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->
    <c- k><c- k>constexpr</c-></c-> <c- n><c- n>const_iterator</c-></c-> <c- nf><c- nf>cend</c-></c-><c- p><c- p>()</c-></c-> <c- k><c- k>const</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->

  <c- k><c- k>private</c-></c-><c- o><c- o>:</c-></c->
    <c- n><c- n>storage_type</c-></c-> <c- n><c- n>arr</c-></c-><c- p><c- p>;</c-></c-> <c- c1><c- c1>// exposition-only</c-></c->
  <c- p><c- p>};</c-></c->

  <i><c- c1><c- c1>// 16.�.5, string literal range access</c-></c-></i>
  <c- k><c- k>template</c-></c-> <c- o><c- o>&lt;</c-></c-><c- n><c- n>classCharType</c-></c-><c- p><c- p>,</c-></c-> <c- b><c- b>size_t</c-></c-> <c- n><c- n>N</c-></c-><c- o><c- o>></c-></c-> 
  <c- k><c- k>constexpr</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- o><c- o>*</c-></c-> <c- n><c- n>begin</c-></c-> <c- p><c- p>(</c-></c-><c- k><c- k>const</c-></c-> <c- n><c- n>basic_string_literal</c-></c-><chartypeU0002C n><c- o><c- o>&amp;</c-></c-><c- p><c- p>)</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->
  <c- k><c- k>template</c-></c-> <c- o><c- o>&lt;</c-></c-><c- n><c- n>classCharType</c-></c-><c- p><c- p>,</c-></c-> <c- b><c- b>size_t</c-></c-> <c- n><c- n>N</c-></c-><c- o><c- o>></c-></c-> 
  <c- k><c- k>constexpr</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- o><c- o>*</c-></c-> <c- n><c- n>end</c-></c-> <c- p><c- p>(</c-></c-><c- k><c- k>const</c-></c-> <c- n><c- n>basic_string_literal</c-></c-><chartypeU0002C n><c- o><c- o>&amp;</c-></c-><c- p><c- p>)</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->
  <c- k><c- k>template</c-></c-> <c- o><c- o>&lt;</c-></c-><c- n><c- n>classCharType</c-></c-><c- p><c- p>,</c-></c-> <c- b><c- b>size_t</c-></c-> <c- n><c- n>N</c-></c-><c- o><c- o>></c-></c-> 
  <c- k><c- k>constexpr</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- o><c- o>*</c-></c-> <c- n><c- n>cbegin</c-></c-> <c- p><c- p>(</c-></c-><c- k><c- k>const</c-></c-> <c- n><c- n>basic_string_literal</c-></c-><chartypeU0002C n><c- o><c- o>&amp;</c-></c-><c- p><c- p>)</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->
  <c- k><c- k>template</c-></c-> <c- o><c- o>&lt;</c-></c-><c- n><c- n>classCharType</c-></c-><c- p><c- p>,</c-></c-> <c- b><c- b>size_t</c-></c-> <c- n><c- n>N</c-></c-><c- o><c- o>></c-></c-> 
  <c- k><c- k>constexpr</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- o><c- o>*</c-></c-> <c- n><c- n>cend</c-></c-> <c- p><c- p>(</c-></c-><c- k><c- k>const</c-></c-> <c- n><c- n>basic_string_literal</c-></c-><chartypeU0002C n><c- o><c- o>&amp;</c-></c-><c- p><c- p>)</c-></c-> <c- k><c- k>noexcept</c-></c-><c- p><c- p>;</c-></c->

  <c- k><c- k>template</c-></c-> <class chartypeU0002C n size_t>
  <c- nf><c- nf>basic_string_literal</c-></c-><c- p><c- p>(</c-></c-> <c- k><c- k>const</c-></c-> <c- n><c- n>CharType</c-></c-><c- p><c- p>(</c-></c-><c- o><c- o>&amp;</c-></c-><c- p><c- p>)[</c-></c-><c- n><c- n>N</c-></c-><c- p><c- p>]</c-></c-> <c- p><c- p>)</c-></c-> <c- o><c- o>-></c-></c-> <c- n><c- n>basic_string_literal</c-></c-><chartypeU0002C n>


  <c- k><c- k>template</c-></c-> <size_t n>
  <c- k><c- k>using</c-></c-> <c- n><c- n>string_literal</c-></c-> <c- o><c- o>=</c-></c-> <c- n><c- n>basic_string_literal</c-></c-><charU0002C n><c- p><c- p>;</c-></c->
	
  <c- k><c- k>template</c-></c-> <size_t n>
  <c- k><c- k>using</c-></c-> <c- n><c- n>wstring_literal</c-></c-> <c- o><c- o>=</c-></c-> <c- n><c- n>basic_string_literal</c-></c-><wchar_tU0002C n><c- p><c- p>;</c-></c->
	
  <c- k><c- k>template</c-></c-> <size_t n>
  <c- k><c- k>using</c-></c-> <c- n><c- n>u8string_literal</c-></c-> <c- o><c- o>=</c-></c-> <c- n><c- n>basic_string_literal</c-></c-><char8_tU0002C n><c- p><c- p>;</c-></c->
	
  <c- k><c- k>template</c-></c-> <size_t n>
  <c- k><c- k>using</c-></c-> <c- n><c- n>u16string_literal</c-></c-> <c- o><c- o>=</c-></c-> <c- n><c- n>basic_string_literal</c-></c-><char16_tU0002C n><c- p><c- p>;</c-></c->
	
  <c- k><c- k>template</c-></c-> <size_t n>
  <c- k><c- k>using</c-></c-> <c- n><c- n>u32string_literal</c-></c-> <c- o><c- o>=</c-></c-> <c- n><c- n>basic_string_literal</c-></c-><char32_tU0002C n><c- p><c- p>;</c-></c->

<c- p><c- p>}</c-></c->
</char32_tU0002C></size_t></char16_tU0002C></size_t></char8_tU0002C></size_t></wchar_tU0002C></size_t></charU0002C></size_t></chartypeU0002C></class></chartypeU0002C></chartypeU0002C></chartypeU0002C></chartypeU0002C></code></pre>
    </ins>
    <ins>
     <div class="numbered">
      An object of type <code class="highlight"><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>></c-></code> provides access to an array of objects of type <code class="highlight"><c- k>const</c-> <c- n>CharType</c-></code>. [<i>Note:</i> Copying a <code class="highlight"><c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>></c-></code> copies the underlying elements. <i>—end note</i>] 
      <div class="numbered">If an explicit specialization or partial specialization of <code class="highlight"><c- n>basic_string_literal</c-></code> is declared, the program is ill-formed.</div>
     </div>
    </ins>
   </blockquote>
   <blockquote>
    <ins>
      <b>16.�.2 String literal constructors <span style="float: right;">[<strong>stringlit.cons</strong>]</span></b> 
     <p><code class="highlight"><c- k>constexpr</c-> <c- nf>basic_string_literal</c-><c- p>()</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: Constructs an empty <code class="highlight"><c- n>basic_string_literal</c-></code> object.</i></div>
     <div class="numbered"><i>Ensures:</i> <code class="highlight"><c- n>size</c-><c- p>()</c-> <c- o>==</c-> <c- mi>0</c-></code> and <code class="highlight"><c- o>*</c-><c- n>end</c-><c- p>()</c-> <c- o>==</c-> <c- sc>'\0'</c-></code>.</div>
     <p><b>16.�.3 String literal conversions <span style="float: right;">[<strong>stringlit.conv</strong>]</span></b></p>
     <p><code class="highlight"><c- k>operator</c-> <c- n>storage_type</c-><c- o>&amp;</c-><c- p>()</c-> <c- k>const</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>arr</c-></code>.</i></div>
    </ins>
   </blockquote>
   <blockquote>
    <ins>
      <b>16.�.4 String literal access <span style="float: right;">[<strong>stringlit.access</strong>]</span></b> 
     <p><code class="highlight"><c- k>constexpr</c-> <c- k>const</c-> <c- n>CharType</c-><c- o>*</c-> <c- nf>data</c-><c- p>()</c-> <c- k>const</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>arr</c-></code>.</i></div>
     <p><code class="highlight"><c- k>constexpr</c-> <c- k>const</c-> <c- n>CharType</c-><c- o>*</c-> <c- nf>c_str</c-><c- p>()</c-> <c- k>const</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>arr</c-></code>.</i></div>
     <p><code class="highlight"><c- k>constexpr</c-> <c- n>size_type</c-> <c- nf>size</c-><c- p>()</c-> <c- k>const</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>N</c-></code>.</i></div>
     <p><code class="highlight"><c- k>constexpr</c-> <c- k>const</c-> <c- n>CharType</c-><c- o>*</c-> <c- nf>begin</c-><c- p>()</c-> <c- k>const</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>arr</c-></code>.</i></div>
     <p><code class="highlight"><c- k>constexpr</c-> <c- k>const</c-> <c- n>CharType</c-><c- o>*</c-> <c- nf>end</c-><c- p>()</c-> <c- k>const</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>begin</c-><c- p>()</c-> <c- o>+</c-> <c- n>size</c-><c- p>()</c-></code>.</i></div>
     <p><code class="highlight"><c- k>constexpr</c-> <c- k>const</c-> <c- n>CharType</c-><c- o>*</c-> <c- nf>cbegin</c-><c- p>()</c-> <c- k>const</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>arr</c-></code>.</i></div>
     <p><code class="highlight"><c- k>constexpr</c-> <c- k>const</c-> <c- n>CharType</c-><c- o>*</c-> <c- nf>cend</c-><c- p>()</c-> <c- k>const</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>cbegin</c-><c- p>()</c-> <c- o>+</c-> <c- n>size</c-><c- p>()</c-></code>.</i></div>
    </ins>
   </blockquote>
   <blockquote>
    <ins>
      <b>16.�.5 String literal range access <span style="float: right;">[<strong>stringlit.range</strong>]</span></b> 
     <p><code class="highlight"><c- k>template</c-> <c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- b>size_t</c-> <c- n>N</c-><c- o>></c-> <c- k>constexpr</c-> <c- k>const</c-> <c- n>CharType</c-><c- o>*</c-> <c- n>begin</c-> <c- p>(</c-><c- k>const</c-> <c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>>&amp;</c-> <c- n>lit</c-><c- p>)</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>lit</c-><c- p>.</c-><c- n>begin</c-><c- p>()</c-></code>.</i></div>
     <p><code class="highlight"><c- k>template</c-> <c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- b>size_t</c-> <c- n>N</c-><c- o>></c-> <c- k>constexpr</c-> <c- k>const</c-> <c- n>CharType</c-><c- o>*</c-> <c- n>end</c-> <c- p>(</c-><c- k>const</c-> <c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>>&amp;</c-><c- p>)</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>lit</c-><c- p>.</c-><c- n>end</c-><c- p>()</c-></code>.</i></div>
     <p><code class="highlight"><c- k>template</c-> <c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- b>size_t</c-> <c- n>N</c-><c- o>></c-> <c- k>constexpr</c-> <c- k>const</c-> <c- n>CharType</c-><c- o>*</c-> <c- n>cbegin</c-> <c- p>(</c-><c- k>const</c-> <c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>>&amp;</c-><c- p>)</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>lit</c-><c- p>.</c-><c- n>cbegin</c-><c- p>()</c-></code>.</i></div>
     <p><code class="highlight"><c- k>template</c-> <c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- b>size_t</c-> <c- n>N</c-><c- o>></c-> <c- k>constexpr</c-> <c- k>const</c-> <c- n>CharType</c-><c- o>*</c-> <c- n>cend</c-> <c- p>(</c-><c- k>const</c-> <c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>CharType</c-><c- p>,</c-> <c- n>N</c-><c- o>>&amp;</c-><c- p>)</c-> <c- k>noexcept</c-><c- p>;</c-></code></p>
     <div class="numbered"><i>Effects: returns <code class="highlight"><c- n>lit</c-><c- p>.</c-><c- n>cend</c-><c- p>()</c-></code>.</i></div>
    </ins>
   </blockquote>
   <p>Modify §20.3.2 [<strong>basic.string</strong>] to add the following constructor:</p>
   <blockquote>
    <ins> <code class="highlight"><c- k>template</c-> <c- o>&lt;</c-><c- b>size_t</c-> <c- n>N</c-><c- o>></c-> <c- n>basic_string</c-><c- p>(</c-><c- k>const</c-> <c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>charT</c-><c- p>,</c-> <c- n>N</c-><c- o>>&amp;</c-><c- p>);</c-></code> </ins>
   </blockquote>
   <p>Modify §20.3.2.3 [<strong>string.cons</strong>] to add the following constructor:</p>
   <blockquote>
    <ins>
      <code class="highlight"><c- k>template</c-> <c- o>&lt;</c-><c- b>size_t</c-> <c- n>N</c-><c- o>></c-> <c- n>basic_string</c-><c- p>(</c-><c- k>const</c-> <c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>charT</c-><c- p>,</c-> <c- n>N</c-><c- o>>&amp;</c-> <c- n>lit</c-><c- p>);</c-></code> 
     <div class="newnumbered"><i>Effects: behaves the same as if invoking: <code class="highlight"><c- n>basic_string</c-><c- p>(</c-><c- n>lit</c-><c- p>.</c-><c- n>data</c-><c- p>(),</c-> <c- n>lit</c-><c- p>.</c-><c- n>size</c-><c- p>())</c-></code>.</i></div>
    </ins>
   </blockquote>
   <p>Modify §20.4.2 [<strong>string.view.template</strong>] to add the following constructor:</p>
   <blockquote>
    <ins> <code class="highlight"><c- k>template</c-> <c- o>&lt;</c-><c- b>size_t</c-> <c- n>N</c-><c- o>></c-> <c- n>basic_string</c-><c- p>(</c-><c- k>const</c-> <c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>charT</c-><c- p>,</c-> <c- n>N</c-><c- o>>&amp;</c-><c- p>);</c-></code> </ins>
   </blockquote>
   <p>Modify §20.4.2.1 [<strong>string.view.cons</strong>] to add the following constructor:</p>
   <blockquote>
    <ins>
      <code class="highlight"><c- k>template</c-> <c- o>&lt;</c-><c- b>size_t</c-> <c- n>N</c-><c- o>></c-> <c- n>basic_string_view</c-><c- p>(</c-><c- k>const</c-> <c- n>basic_string_literal</c-><c- o>&lt;</c-><c- n>charT</c-><c- p>,</c-> <c- n>N</c-><c- o>>&amp;</c-> <c- n>lit</c-><c- p>);</c-></code> 
     <div class="newnumbered"><i>Effects: behaves the same as if invoking: <code class="highlight"><c- n>basic_string_view</c-><c- p>(</c-><c- n>lit</c-><c- p>.</c-><c- n>data</c-><c- p>(),</c-> <c- n>lit</c-><c- p>.</c-><c- n>size</c-><c- p>())</c-></code>.</i></div>
    </ins>
   </blockquote>
   <h2 class="heading settled" data-level="5" id="acknowledgements"><span class="secno">5. </span><span class="content">Acknowledgements</span><a class="self-link" href="#acknowledgements"></a></h2>
   <p>Thanks to Colby Pike (vector-of-bool) for helping to incubate and brew this idea. Thanks to Jason Turner for elaborating in quite a bit of detail the pitfalls of string initialization and the need for a string literal type.</p>
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  <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-n4762">[N4762]
   <dd>ISO/IEC JTC1/SC22/WG21 - The C++ Standards Committee; Richard Smith. <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/n4762.pdf">N4762 - Working Draft, Standard for Programming Language C++</a>. May 7th, 2018. URL: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/n4762.pdf">http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/n4762.pdf</a>
   <dt id="biblio-p0259">[P0259]
   <dd>Michael Price; Andrew Tomazos. <a href="https://wg21.link/p0259">fixed_string: a compile-time string</a>. 2016. URL: <a href="https://wg21.link/p0259">https://wg21.link/p0259</a>
   <dt id="biblio-p0424">[P0424]
   <dd>Louis Dionne; Hana Dusíková. <a href="https://wg21.link/p0424">String literals as non-type template parameters</a>. November 14th, 2017. URL: <a href="https://wg21.link/p0424">https://wg21.link/p0424</a>
   <dt id="biblio-p0732">[P0732]
   <dd>Jeff Snyder; Louis Dionne. <a href="https://wg21.link/p0732">Class Types in Non-Type Template Parameters</a>. June 6th, 2018. URL: <a href="https://wg21.link/p0732">https://wg21.link/p0732</a>
   <dt id="biblio-p1040">[P1040]
   <dd>JeanHeyd Meneide. <a href="https://wg21.link/p1040">std::embed</a>. October 12th, 2018. URL: <a href="https://wg21.link/p1040">https://wg21.link/p1040</a>
  </dl>