<!DOCTYPE html>
<html lang="en"><head>
  <meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
  <meta content="width=device-width, initial-scale=1, shrink-to-fit=no" name="viewport">
  <title>P1810R0: A Quick Look at What P1754 Will Change</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 {
		border-bottom: 2px solid;
	}

	table.data colgroup,
	table.index colgroup {
		border-left: 2px solid;
	}

	table.data  tbody th:first-child,
	table.index tbody th:first-child  {
		border-right: 2px solid;
		border-top: 1px solid silver;
		padding-right: 1em;
	}

	table.data th[colspan],
	table.data td[colspan] {
		text-align: center;
	}

	table.complex.data th,
	table.complex.data td {
		border: 1px solid silver;
		text-align: center;
	}

	table.data.longlastcol td:last-child,
	table.data td.long {
	 vertical-align: baseline;
	 text-align: left;
	}

	table.data img {
		vertical-align: middle;
	}


/*
Alternate table alignment rules

	table.data,
	table.index {
		text-align: center;
	}

	table.data  thead th[scope="row"],
	table.index thead th[scope="row"] {
		text-align: right;
	}

	table.data  tbody th:first-child,
	table.index tbody th:first-child  {
		text-align: right;
	}

Possible extra rowspan handling

	table.data  tbody th[rowspan]:not([rowspan='1']),
	table.index tbody th[rowspan]:not([rowspan='1']),
	table.data  tbody td[rowspan]:not([rowspan='1']),
	table.index tbody td[rowspan]:not([rowspan='1']) {
		border-left: 1px solid silver;
	}

	table.data  tbody th[rowspan]:first-child,
	table.index tbody th[rowspan]:first-child,
	table.data  tbody td[rowspan]:first-child,
	table.index tbody td[rowspan]:first-child{
		border-left: 0;
		border-right: 1px solid silver;
	}
*/

/******************************************************************************/
/*                                  Indices                                   */
/******************************************************************************/


/** Table of Contents *********************************************************/

	.toc a {
		/* More spacing; use padding to make it part of the click target. */
		padding-top: 0.1rem;
		/* Larger, more consistently-sized click target */
		display: block;
		/* Reverse color scheme */
		color: black;
		border-color: #3980B5;
		border-bottom-width: 3px !important;
		margin-bottom: 0px !important;
	}
	.toc a:visited {
		border-color: #054572;
	}
	.toc a:not(:focus):not(:hover) {
		/* Allow colors to cascade through from link styling */
		border-bottom-color: transparent;
	}

	.toc, .toc ol, .toc ul, .toc li {
		list-style: none; /* Numbers must be inlined into source */
		/* because generated content isn't search/selectable and markers can't do multilevel yet */
		margin:  0;
		padding: 0;
		line-height: 1.1rem; /* consistent spacing */
	}

	/* ToC not indented until third level, but font style & margins show hierarchy */
	.toc > li             { font-weight: bold;   }
	.toc > li li          { font-weight: normal; }
	.toc > li li li       { font-size:   95%;    }
	.toc > li li li li    { font-size:   90%;    }
	.toc > li li li li .secno { font-size: 85%; }
	.toc > li li li li li { font-size:   85%;    }
	.toc > li li li li li .secno { font-size: 100%; }

	/* @supports not (display:grid) { */
		.toc > li             { margin: 1.5rem 0;    }
		.toc > li li          { margin: 0.3rem 0;    }
		.toc > li li li       { margin-left: 2rem;   }

		/* Section numbers in a column of their own */
		.toc .secno {
			float: left;
			width: 4rem;
			white-space: nowrap;
		}

		.toc li {
			clear: both;
		}

		:not(li) > .toc              { margin-left:  5rem; }
		.toc .secno                  { margin-left: -5rem; }
		.toc > li li li .secno       { margin-left: -7rem; }
		.toc > li li li li .secno    { margin-left: -9rem; }
		.toc > li li li li li .secno { margin-left: -11rem; }

		/* Tighten up indentation in narrow ToCs */
		@media (max-width: 30em) {
			:not(li) > .toc              { margin-left:  4rem; }
			.toc .secno                  { margin-left: -4rem; }
			.toc > li li li              { margin-left:  1rem; }
			.toc > li li li .secno       { margin-left: -5rem; }
			.toc > li li li li .secno    { margin-left: -6rem; }
			.toc > li li li li li .secno { margin-left: -7rem; }
		}
	/* } */

	@supports (display:grid) and (display:contents) {
		/* Use #toc over .toc to override non-@supports rules. */
		#toc {
			display: grid;
			align-content: start;
			grid-template-columns: auto 1fr;
			grid-column-gap: 1rem;
			column-gap: 1rem;
			grid-row-gap: .6rem;
			row-gap: .6rem;
		}
		#toc h2 {
			grid-column: 1 / -1;
			margin-bottom: 0;
		}
		#toc ol,
		#toc li,
		#toc a {
			display: contents;
			/* Switch <a> to subgrid when supported */
		}
		#toc span {
			margin: 0;
		}
		#toc > .toc > li > a > span {
			/* The spans of the top-level list,
			   comprising the first items of each top-level section. */
			margin-top: 1.1rem;
		}
		#toc#toc .secno { /* Ugh, need more specificity to override base.css */
			grid-column: 1;
			width: auto;
			margin-left: 0;
		}
		#toc .content {
			grid-column: 2;
			width: auto;
			margin-right: 1rem;
		}
		#toc .content:hover {
			background: rgba(75%, 75%, 75%, .25);
			border-bottom: 3px solid #054572;
			margin-bottom: -3px;
		}
		#toc li li li .content {
			margin-left: 1rem;
		}
		#toc li li li li .content {
			margin-left: 2rem;
		}
	}


/** Index *********************************************************************/

	/* Index Lists: Layout */
	ul.index       { margin-left: 0; columns: 15em; text-indent: 1em hanging; }
	ul.index li    { margin-left: 0; list-style: none; break-inside: avoid; }
	ul.index li li { margin-left: 1em }
	ul.index dl    { margin-top: 0; }
	ul.index dt    { margin: .2em 0 .2em 20px;}
	ul.index dd    { margin: .2em 0 .2em 40px;}
	/* Index Lists: Typography */
	ul.index ul,
	ul.index dl { font-size: smaller; }
	@media not print {
		ul.index li span {
			white-space: nowrap;
			color: transparent; }
		ul.index li a:hover + span,
		ul.index li a:focus + span {
			color: #707070;
		}
	}

/** Index Tables *****************************************************/
	/* See also the data table styling section, which this effectively subclasses */

	table.index {
		font-size: small;
		border-collapse: collapse;
		border-spacing: 0;
		text-align: left;
		margin: 1em 0;
	}

	table.index td,
	table.index th {
		padding: 0.4em;
	}

	table.index tr:hover td:not([rowspan]),
	table.index tr:hover th:not([rowspan]) {
		background: #f7f8f9;
	}

	/* The link in the first column in the property table (formerly a TD) */
	table.index th:first-child a {
		font-weight: bold;
	}

/******************************************************************************/
/*                                    Print                                   */
/******************************************************************************/

	@media print {
		/* Pages have their own margins. */
		html {
			margin: 0;
		}
		/* Serif for print. */
		body {
			font-family: serif;
		}
	}
	@page {
		margin: 1.5cm 1.1cm;
	}

/******************************************************************************/
/*                                    Legacy                                  */
/******************************************************************************/

	/* This rule is inherited from past style sheets. No idea what it's for. */
	.hide { display: none }



/******************************************************************************/
/*                             Overflow Control                               */
/******************************************************************************/

	.figure .caption, .sidefigure .caption, figcaption {
		/* in case figure is overlarge, limit caption to 50em */
		max-width: 50rem;
		margin-left: auto;
		margin-right: auto;
	}
	.overlarge > table {
		/* limit preferred width of table */
		max-width: 50em;
		margin-left: auto;
		margin-right: auto;
	}

	@media (min-width: 55em) {
		.overlarge {
			margin-left: calc(13px + 26.5rem - 50vw);
			margin-right: calc(13px + 26.5rem - 50vw);
			max-width: none;
		}
	}
	@media screen and (min-width: 78em) {
		body:not(.toc-inline) .overlarge {
			/* 30.5em body padding 50em content area */
			margin-left: calc(40em - 50vw) !important;
			margin-right: calc(40em - 50vw) !important;
		}
	}
	@media screen and (min-width: 90em) {
		body:not(.toc-inline) .overlarge {
			/* 4em html margin 30.5em body padding 50em content area */
			margin-left: 0 !important;
			margin-right: calc(84.5em - 100vw) !important;
		}
	}

	@media not print {
		.overlarge {
			overflow-x: auto;
			/* See Lea Verou's explanation background-attachment:
			 * http://lea.verou.me/2012/04/background-attachment-local/
			 *
			background: top left  / 4em 100% linear-gradient(to right,  #ffffff, rgba(255, 255, 255, 0)) local,
			            top right / 4em 100% linear-gradient(to left, #ffffff, rgba(255, 255, 255, 0)) local,
			            top left  / 1em 100% linear-gradient(to right,  #c3c3c5, rgba(195, 195, 197, 0)) scroll,
			            top right / 1em 100% linear-gradient(to left, #c3c3c5, rgba(195, 195, 197, 0)) scroll,
			            white;
			background-repeat: no-repeat;
			*/
		}
	}
</style>
<style type="text/css">
    table, th, td {
      border: 1px solid black;
      border-collapse: collapse;
      vertical-align: top;
    }
    th, td {
      border-left: none;
      border-right: none;
      padding: 0px 10px;
    }
    th {
      text-align: center;
    }
  </style>
  <meta content="Bikeshed version 30aa90d768746168deba12493f1f3622df2814b6" name="generator">
  <link href="https://wg21.link/p1810" rel="canonical">
  <link href="https://isocpp.org/favicon.ico" rel="icon">
  <meta content="d4268026804329fe476319cbc1aacbf745ec43b3" name="document-revision">
<style>/* style-md-lists */

/* This is a weird hack for me not yet following the commonmark spec
   regarding paragraph and lists. */
[data-md] > :first-child {
    margin-top: 0;
}
[data-md] > :last-child {
    margin-bottom: 0;
}</style>
<style>/* style-counters */

body {
    counter-reset: example figure issue;
}
.issue {
    counter-increment: issue;
}
.issue:not(.no-marker)::before {
    content: "Issue " counter(issue);
}

.example {
    counter-increment: example;
}
.example:not(.no-marker)::before {
    content: "Example " counter(example);
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.invalid.example:not(.no-marker)::before,
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    content: "Invalid Example" counter(example);
}

figcaption {
    counter-increment: figure;
}
figcaption:not(.no-marker)::before {
    content: "Figure " counter(figure) " ";
}</style>
<style>/* style-syntax-highlighting */

.highlight:not(.idl) { background: hsl(24, 20%, 95%); }
code.highlight { padding: .1em; border-radius: .3em; }
pre.highlight, pre > code.highlight { display: block; padding: 1em; margin: .5em 0; overflow: auto; border-radius: 0; }
c-[a] { color: #990055 } /* Keyword.Declaration */
c-[b] { color: #990055 } /* Keyword.Type */
c-[c] { color: #708090 } /* Comment */
c-[d] { color: #708090 } /* Comment.Multiline */
c-[e] { color: #0077aa } /* Name.Attribute */
c-[f] { color: #669900 } /* Name.Tag */
c-[g] { color: #222222 } /* Name.Variable */
c-[k] { color: #990055 } /* Keyword */
c-[l] { color: #000000 } /* Literal */
c-[m] { color: #000000 } /* Literal.Number */
c-[n] { color: #0077aa } /* Name */
c-[o] { color: #999999 } /* Operator */
c-[p] { color: #999999 } /* Punctuation */
c-[s] { color: #a67f59 } /* Literal.String */
c-[t] { color: #a67f59 } /* Literal.String.Single */
c-[u] { color: #a67f59 } /* Literal.String.Double */
c-[cp] { color: #708090 } /* Comment.Preproc */
c-[c1] { color: #708090 } /* Comment.Single */
c-[cs] { color: #708090 } /* Comment.Special */
c-[kc] { color: #990055 } /* Keyword.Constant */
c-[kn] { color: #990055 } /* Keyword.Namespace */
c-[kp] { color: #990055 } /* Keyword.Pseudo */
c-[kr] { color: #990055 } /* Keyword.Reserved */
c-[ld] { color: #000000 } /* Literal.Date */
c-[nc] { color: #0077aa } /* Name.Class */
c-[no] { color: #0077aa } /* Name.Constant */
c-[nd] { color: #0077aa } /* Name.Decorator */
c-[ni] { color: #0077aa } /* Name.Entity */
c-[ne] { color: #0077aa } /* Name.Exception */
c-[nf] { color: #0077aa } /* Name.Function */
c-[nl] { color: #0077aa } /* Name.Label */
c-[nn] { color: #0077aa } /* Name.Namespace */
c-[py] { color: #0077aa } /* Name.Property */
c-[ow] { color: #999999 } /* Operator.Word */
c-[mb] { color: #000000 } /* Literal.Number.Bin */
c-[mf] { color: #000000 } /* Literal.Number.Float */
c-[mh] { color: #000000 } /* Literal.Number.Hex */
c-[mi] { color: #000000 } /* Literal.Number.Integer */
c-[mo] { color: #000000 } /* Literal.Number.Oct */
c-[sb] { color: #a67f59 } /* Literal.String.Backtick */
c-[sc] { color: #a67f59 } /* Literal.String.Char */
c-[sd] { color: #a67f59 } /* Literal.String.Doc */
c-[se] { color: #a67f59 } /* Literal.String.Escape */
c-[sh] { color: #a67f59 } /* Literal.String.Heredoc */
c-[si] { color: #a67f59 } /* Literal.String.Interpol */
c-[sx] { color: #a67f59 } /* Literal.String.Other */
c-[sr] { color: #a67f59 } /* Literal.String.Regex */
c-[ss] { color: #a67f59 } /* Literal.String.Symbol */
c-[vc] { color: #0077aa } /* Name.Variable.Class */
c-[vg] { color: #0077aa } /* Name.Variable.Global */
c-[vi] { color: #0077aa } /* Name.Variable.Instance */
c-[il] { color: #000000 } /* Literal.Number.Integer.Long */
</style>
<style>/* style-selflinks */

.heading, .issue, .note, .example, li, dt {
    position: relative;
}
a.self-link {
    position: absolute;
    top: 0;
    left: calc(-1 * (3.5rem - 26px));
    width: calc(3.5rem - 26px);
    height: 2em;
    text-align: center;
    border: none;
    transition: opacity .2s;
    opacity: .5;
}
a.self-link:hover {
    opacity: 1;
}
.heading > a.self-link {
    font-size: 83%;
}
li > a.self-link {
    left: calc(-1 * (3.5rem - 26px) - 2em);
}
dfn > a.self-link {
    top: auto;
    left: auto;
    opacity: 0;
    width: 1.5em;
    height: 1.5em;
    background: gray;
    color: white;
    font-style: normal;
    transition: opacity .2s, background-color .2s, color .2s;
}
dfn:hover > a.self-link {
    opacity: 1;
}
dfn > a.self-link:hover {
    color: black;
}

a.self-link::before            { content: "¶"; }
.heading > a.self-link::before { content: "§"; }
dfn > a.self-link::before      { content: "#"; }</style>
<style>/* style-autolinks */

.css.css, .property.property, .descriptor.descriptor {
    color: #005a9c;
    font-size: inherit;
    font-family: inherit;
}
.css::before, .property::before, .descriptor::before {
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}
.css::after, .property::after, .descriptor::after {
    content: "’";
}
.property, .descriptor {
    /* Don't wrap property and descriptor names */
    white-space: nowrap;
}
.type { /* CSS value <type> */
    font-style: italic;
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pre .property::before, pre .property::after {
    content: "";
}
[data-link-type="property"]::before,
[data-link-type="propdesc"]::before,
[data-link-type="descriptor"]::before,
[data-link-type="value"]::before,
[data-link-type="function"]::before,
[data-link-type="at-rule"]::before,
[data-link-type="selector"]::before,
[data-link-type="maybe"]::before {
    content: "‘";
}
[data-link-type="property"]::after,
[data-link-type="propdesc"]::after,
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[data-link-type="function"]::after,
[data-link-type="at-rule"]::after,
[data-link-type="selector"]::after,
[data-link-type="maybe"]::after {
    content: "’";
}

[data-link-type].production::before,
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.prod [data-link-type]::before,
.prod [data-link-type]::after {
    content: "";
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[data-link-type=element],
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[data-link-type=element]::before { content: "<" }
[data-link-type=element]::after  { content: ">" }

[data-link-type=biblio] {
    white-space: pre;
}</style>
 </head><body class="h-entry toc-sidebar"><p id="toc-nav"><a id="toc-jump" href="#toc"><span aria-hidden="true">↑</span> <span>Jump to Table of Contents</span></a><a id="toc-toggle" href="#toc"><span aria-hidden="true">←</span> <span>Collapse Sidebar</span></a></p>
  <div class="head">
   <p data-fill-with="logo"></p>
   <h1 class="p-name no-ref" id="title">P1810R0<br>A Quick Look at What P1754 Will Change</h1>
   <h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Draft Proposal, <time class="dt-updated" datetime="2012-07-12">2012-07-12</time></span></h2>
   <div data-fill-with="spec-metadata">
    <dl>
     <dt>This version:
     </dt><dd><a class="u-url" href="https://wg21.link/p1810">https://wg21.link/p1810</a>
     </dd><dt>Author:
     </dt><dd>
      </dd><dd class="editor p-author h-card vcard"><a class="p-name fn u-email email" href="mailto:cjdb.ns@gmail.com">Christopher Di Bella</a>
     </dd><dt>Audience:
     </dt><dd>EWG, LEWG, LWG
     </dd><dt>Project:
     </dt><dd>ISO/IEC JTC1/SC22/WG21 14882: Programming Language — C++
    </dd></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><a data-link-type="biblio" href="#biblio-p1754">[P1754]</a> has a
single, abundantly clear goal outlined in its name: to change the naming
 convention for all standard concepts from `PascalCase` to `snake_case`.
 Examples in P1754 are sadly lacking: it would have been nice to see an
algorithm or two with the differences displayed side-by-side. I was
curious about what it would look like, so I decided to contrast the two
using the library that’s benefited from concepts the most: our
algorithms library.</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="#examples"><span class="secno">1</span> <span class="content">Examples</span></a>
     <ol class="toc">
      <li><a href="#concerns-and-the-status-quo"><span class="secno">1.1</span> <span class="content">Concerns and the status quo</span></a>
      </li><li><a href="#whos-co-authoring-it"><span class="secno">1.2</span> <span class="content">Who’s co-authoring it?</span></a>
     </li></ol>
    </li><li>
     <a href="#thoughts-on-the-new-concept-names"><span class="secno">2</span> <span class="content">Thoughts on the new concept names</span></a>
     <ol class="toc">
      <li><a href="#favoured-renamings"><span class="secno">2.1</span> <span class="content">Favoured renamings</span></a>
      </li><li><a href="#bikeshedding"><span class="secno">2.2</span> <span class="content">Bikeshedding</span></a>
     </li></ol>
    </li><li><a href="#conclusion"><span class="secno">3</span> <span class="content">Conclusion</span></a>
    </li><li>
     <a href="#references"><span class="secno"></span> <span class="content">References</span></a>
     <ol class="toc">
      <li><a href="#normative"><span class="secno"></span> <span class="content">Normative References</span></a>
      </li><li><a href="#informative"><span class="secno"></span> <span class="content">Informative References</span></a>
     </li></ol>
   </li></ol>
  </nav>
  <main>
   <h2 class="heading settled" data-level="1" id="examples"><span class="secno">1. </span><span class="content">Examples</span><a class="self-link" href="#examples"></a></h2>
<pre class="language-cpp highlight"><c- c1="">// Status quo</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- n="">InputIterator</c-> <c- n="">I</c-><c- p="">,</c-> <c- n="">Sentinel</c-><c- o="">&lt;</c-><c- n="">I</c-><c- o="">&gt;</c-> <c- n="">S</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">T</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">Proj</c-> <c- o="">=</c-> <c- n="">identity</c-><c- o="">&gt;</c->
<c- n="">requires</c-> <c- n="">IndirectRelation</c-><c- o="">&lt;</c-><c- n="">ranges</c-><c- o="">::</c-><c- n="">equal_to</c-><c- p="">,</c-> <c- n="">projected</c-><c- o="">&lt;</c-><c- n="">I</c-><c- p="">,</c-> <c- n="">Proj</c-><c- o="">&gt;</c-><c- p="">,</c-> <c- n="">T</c-><c- o="">*&gt;</c->
<c- k="">constexpr</c-> <c- n="">I</c-> <c- n="">find</c-><c- p="">(</c-><c- n="">I</c-> <c- n="">first</c-><c- p="">,</c-> <c- n="">S</c-> <c- n="">last</c-><c- p="">,</c-> <c- k="">const</c-> <c- n="">T</c-><c- o="">&amp;</c-> <c- n="">value</c-><c- p="">,</c-> <c- n="">Proj</c-> <c- n="">proj</c-> <c- o="">=</c-> <c- p="">{});</c->

<c- c1="">// P1754’s suggestion</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- n="">input_iterator</c-> <c- n="">I</c-><c- p="">,</c-> <c- n="">sentinel_for</c-><c- o="">&lt;</c-><c- n="">I</c-><c- o="">&gt;</c-> <c- n="">S</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">T</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">Proj</c-> <c- o="">=</c-> <c- n="">identity</c-><c- o="">&gt;</c->
<c- n="">requires</c-> <c- n="">indirect_relation</c-><c- o="">&lt;</c-><c- n="">ranges</c-><c- o="">::</c-><c- n="">equal_to</c-><c- p="">,</c-> <c- n="">projected</c-><c- o="">&lt;</c-><c- n="">I</c-><c- p="">,</c-> <c- n="">Proj</c-><c- o="">&gt;</c-><c- p="">,</c-> <c- n="">T</c-><c- o="">*&gt;</c->
<c- k="">constexpr</c-> <c- n="">I</c-> <c- n="">find</c-><c- p="">(</c-><c- n="">I</c-> <c- n="">first</c-><c- p="">,</c-> <c- n="">S</c-> <c- n="">last</c-><c- p="">,</c-> <c- k="">const</c-> <c- n="">T</c-><c- o="">&amp;</c-> <c- n="">value</c-><c- p="">,</c-> <c- n="">Proj</c-> <c- n="">proj</c-> <c- o="">=</c-> <c- p="">{});</c->
</pre>
<pre class="language-cpp highlight"><c- c1="">// Status quo</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- n="">ForwardIterator</c-> <c- n="">I</c-><c- p="">,</c-> <c- n="">Sentinel</c-><c- o="">&lt;</c-><c- n="">I</c-><c- o="">&gt;</c-> <c- n="">S</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">T</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">Proj</c-> <c- o="">=</c-> <c- n="">identity</c-><c- p="">,</c->
         <c- n="">IndirectStrictWeakOrder</c-><c- o="">&lt;</c-><c- k="">const</c-> <c- n="">T</c-><c- o="">*</c-><c- p="">,</c-> <c- n="">projected</c-><c- o="">&lt;</c-><c- n="">I</c-><c- p="">,</c-> <c- n="">Proj</c-><c- o="">&gt;&gt;</c-> <c- n="">Comp</c-> <c- o="">=</c-> <c- n="">ranges</c-><c- o="">::</c-><c- n="">less</c-><c- o="">&gt;</c->
<c- k="">constexpr</c-> <c- n="">I</c-> <c- n="">upper_bound</c-><c- p="">(</c-><c- n="">I</c-> <c- n="">first</c-><c- p="">,</c-> <c- n="">S</c-> <c- n="">last</c-><c- p="">,</c-> <c- k="">const</c-> <c- n="">T</c-><c- o="">&amp;</c-> <c- n="">value</c-><c- p="">,</c-> <c- n="">Comp</c-> <c- n="">comp</c-> <c- o="">=</c-> <c- p="">{},</c-> <c- n="">Proj</c-> <c- n="">proj</c-> <c- o="">=</c-> <c- p="">{});</c->

<c- c1="">// P1754’s suggestion</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- n="">forward_iterator</c-> <c- n="">I</c-><c- p="">,</c-> <c- n="">sentinel_for</c-><c- o="">&lt;</c-><c- n="">I</c-><c- o="">&gt;</c-> <c- n="">S</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">T</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">Proj</c-> <c- o="">=</c-> <c- n="">identity</c-><c- p="">,</c->
         <c- n="">indirect_strict_weak_order</c-><c- o="">&lt;</c-><c- k="">const</c-> <c- n="">T</c-><c- o="">*</c-><c- p="">,</c-> <c- n="">projected</c-><c- o="">&lt;</c-><c- n="">I</c-><c- p="">,</c-> <c- n="">Proj</c-><c- o="">&gt;&gt;</c-> <c- n="">Comp</c-> <c- o="">=</c-> <c- n="">ranges</c-><c- o="">::</c-><c- n="">less</c-><c- o="">&gt;</c->
<c- k="">constexpr</c-> <c- n="">I</c-> <c- n="">upper_bound</c-><c- p="">(</c-><c- n="">I</c-> <c- n="">first</c-><c- p="">,</c-> <c- n="">S</c-> <c- n="">last</c-><c- p="">,</c-> <c- k="">const</c-> <c- n="">T</c-><c- o="">&amp;</c-> <c- n="">value</c-><c- p="">,</c-> <c- n="">Comp</c-> <c- n="">comp</c-> <c- o="">=</c-> <c- p="">{},</c-> <c- n="">Proj</c-> <c- n="">proj</c-> <c- o="">=</c-> <c- p="">{});</c->
</pre>
<pre class="language-cpp highlight"><c- c1="">// Status quo</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- n="">InputIterator</c-> <c- n="">I1</c-><c- p="">,</c-> <c- n="">Sentinel</c-><c- o="">&lt;</c-><c- n="">I1</c-><c- o="">&gt;</c-> <c- n="">S1</c-><c- p="">,</c-> <c- n="">RandomAccessIterator</c-> <c- n="">I2</c-><c- p="">,</c-> <c- n="">Sentinel</c-><c- o="">&lt;</c-><c- n="">I2</c-><c- o="">&gt;</c-> <c- n="">S2</c-><c- p="">,</c->
         <c- k="">class</c-> <c- nc="">Comp</c-> <c- o="">=</c-> <c- n="">ranges</c-><c- o="">::</c-><c- n="">less</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">Proj1</c-> <c- o="">=</c-> <c- n="">identity</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">Proj2</c-> <c- o="">=</c-> <c- n="">identity</c-><c- o="">&gt;</c->
<c- n="">requires</c-> <c- n="">IndirectlyCopyable</c-><c- o="">&lt;</c-><c- n="">I1</c-><c- p="">,</c-> <c- n="">I2</c-><c- o="">&gt;</c-> <c- o="">&amp;&amp;</c-> <c- n="">Sortable</c-><c- o="">&lt;</c-><c- n="">I2</c-><c- p="">,</c-> <c- n="">Comp</c-><c- p="">,</c-> <c- n="">Proj2</c-><c- o="">&gt;</c-> <c- o="">&amp;&amp;</c->
         <c- n="">IndirectStrictWeakOrder</c-><c- o="">&lt;</c-><c- n="">Comp</c-><c- p="">,</c-> <c- n="">projected</c-><c- o="">&lt;</c-><c- n="">I1</c-><c- p="">,</c-> <c- n="">Proj1</c-><c- o="">&gt;</c-><c- p="">,</c-> <c- n="">projected</c-><c- o="">&lt;</c-><c- n="">I2</c-><c- p="">,</c-> <c- n="">Proj2</c-><c- o="">&gt;&gt;</c->
<c- k="">constexpr</c-> <c- n="">I2</c-> <c- n="">partial_sort_copy</c-><c- p="">(</c-><c- n="">I1</c-> <c- n="">first</c-><c- p="">,</c-> <c- n="">S1</c-> <c- n="">last</c-><c- p="">,</c-> <c- n="">I2</c-> <c- n="">result_first</c-><c- p="">,</c-> <c- n="">S2</c-> <c- n="">result_last</c-><c- p="">,</c->
                               <c- n="">Comp</c-> <c- n="">comp</c-> <c- o="">=</c-> <c- p="">{},</c-> <c- n="">Proj1</c-> <c- n="">proj1</c-> <c- o="">=</c-> <c- p="">{},</c-> <c- n="">Proj2</c-> <c- n="">proj2</c-> <c- o="">=</c-> <c- p="">{});</c->

<c- c1="">// P1754’s suggestion</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- n="">input_iterator</c-> <c- n="">I1</c-><c- p="">,</c-> <c- n="">sentinel_for</c-><c- o="">&lt;</c-><c- n="">I1</c-><c- o="">&gt;</c-> <c- n="">S1</c-><c- p="">,</c-> <c- n="">random_access_iterator</c-> <c- n="">I2</c-><c- p="">,</c-> <c- n="">sentinel_for</c-><c- o="">&lt;</c-><c- n="">I2</c-><c- o="">&gt;</c-> <c- n="">S2</c-><c- p="">,</c->
         <c- k="">class</c-> <c- nc="">Comp</c-> <c- o="">=</c-> <c- n="">ranges</c-><c- o="">::</c-><c- n="">less</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">Proj1</c-> <c- o="">=</c-> <c- n="">identity</c-><c- p="">,</c-> <c- k="">class</c-> <c- nc="">Proj2</c-> <c- o="">=</c-> <c- n="">identity</c-><c- o="">&gt;</c->
<c- n="">requires</c-> <c- n="">indirect_copyable</c-><c- o="">&lt;</c-><c- n="">I1</c-><c- p="">,</c-> <c- n="">I2</c-><c- o="">&gt;</c-> <c- o="">&amp;&amp;</c-> <c- n="">sortable</c-><c- o="">&lt;</c-><c- n="">I2</c-><c- p="">,</c-> <c- n="">Comp</c-><c- p="">,</c-> <c- n="">Proj2</c-><c- o="">&gt;</c-> <c- o="">&amp;&amp;</c->
         <c- n="">indirect_strict_weak_order</c-><c- o="">&lt;</c-><c- n="">Comp</c-><c- p="">,</c-> <c- n="">projected</c-><c- o="">&lt;</c-><c- n="">I1</c-><c- p="">,</c-> <c- n="">Proj1</c-><c- o="">&gt;</c-><c- p="">,</c-> <c- n="">projected</c-><c- o="">&lt;</c-><c- n="">I2</c-><c- p="">,</c-> <c- n="">Proj2</c-><c- o="">&gt;&gt;</c->
<c- k="">constexpr</c-> <c- n="">I2</c-> <c- n="">partial_sort_copy</c-><c- p="">(</c-><c- n="">I1</c-> <c- n="">first</c-><c- p="">,</c-> <c- n="">S1</c-> <c- n="">last</c-><c- p="">,</c-> <c- n="">I2</c-> <c- n="">result_first</c-><c- p="">,</c-> <c- n="">S2</c-> <c- n="">result_last</c-><c- p="">,</c->
                               <c- n="">Comp</c-> <c- n="">comp</c-> <c- o="">=</c-> <c- p="">{},</c-> <c- n="">Proj1</c-> <c- n="">proj1</c-> <c- o="">=</c-> <c- p="">{},</c-> <c- n="">Proj2</c-> <c- n="">proj2</c-> <c- o="">=</c-> <c- p="">{});</c->
</pre>
   <p>The underscores serve as spaces in the names, which in my opinion, make the concepts significantly
easier to read -- particularly in the case of <code class="highlight"><c- n="">partial_sort_copy</c-></code>, which is quite a mouthful. I’ve
also applied the <code class="highlight"><c- n="">snake_case</c-></code> concepts to my numeric algorithms proposal, and it’s helped to improve
that document’s readability there too. I imagine production code using the <code class="highlight"><c- n="">snake_case</c-></code> concepts
will benefit even more than the spec.</p>
   <h3 class="heading settled" data-level="1.1" id="concerns-and-the-status-quo"><span class="secno">1.1. </span><span class="content">Concerns and the status quo</span><a class="self-link" href="#concerns-and-the-status-quo"></a></h3>
   <p>I’ve seen many people express distaste for the proposed change side due to the fact that 'we’ve
always named our concepts using <code class="highlight"><c- n="">PascalCase</c-></code>'. We haven’t: we have a set of tables in the standard
library that outline requirements, and we name these requirements <code class="highlight"><c- n="">EqualityComparable</c-></code>, and so on.
While they do use <code class="highlight"><c- n="">PascalCase</c-></code>, those names are used to alias tables that appear only to aid in
understanding the standard prose, and don’t represent any standard identifier.</p>
   <p>Secondly, it’s easy to come to the conclusion that because there’s a named requirement called <code class="highlight"><c- n="">EqualityComparable</c-></code> and a concept called <code class="highlight"><c- n="">EqualityComparable</c-></code>, of course the concept is just a way
for us to express our requirements in a compiler-checkable way. This is misguided: the concept <code class="highlight"><c- n="">EqualityComparable</c-></code> goes way deeper than the named requirement <code class="highlight"><c- n="">EqualityComparable</c-></code>. It is left as
an exercise to the reader to distinguish the differences between the two. (One should note that the
named requirement has been rebranded as <em>Cpp17EqualityComparable</em> to signify that it’s different to
the concept, and that the font face has changed from <code class="highlight"><c- n="">verbatim</c-></code> to <em>italics</em>, which means that there
shouldn’t be any more names in the standard spelt using <code class="highlight"><c- n="">PascalCase</c-></code>.)</p>
   <p>Finally, our current templates look like this:</p>
<pre class="highlight"><c- k="">template</c-><c- o="">&lt;</c-><c- k="">class</c-> <c- nc="">InputIterator</c-><c- o="">&gt;</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- k="">typename</c-> <c- n="">InputIterator</c-><c- o="">&gt;</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- k="">auto</c-> <c- n="">N</c-><c- o="">&gt;</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- b="">int</c-> <c- n="">N</c-><c- o="">&gt;</c->
</pre>
   <p>They do not look like this:</p>
<pre class="highlight"><c- k="">template</c-><c- o="">&lt;</c-><c- n="">Class</c-> <c- n="">I</c-><c- o="">&gt;</c->    <c- c1="">// error: template type parameter declared using 'class' or 'typename'</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- n="">Typename</c-> <c- n="">I</c-><c- o="">&gt;</c-> <c- c1="">// error: template type parameter declared using 'class' or 'typename'</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- n="">Auto</c-> <c- n="">N</c-><c- o="">&gt;</c->     <c- c1="">// error: template non-type parameter declared using 'auto' or an integral type</c->
<c- k="">template</c-><c- o="">&lt;</c-><c- n="">Int</c-> <c- n="">N</c-><c- o="">&gt;</c->      <c- c1="">// error: template non-type parameter declared using 'auto' or an integral type</c->
</pre>
   <p>In other words, my take on this, is that P1754 aims to <em>restore</em> what we’ve always done, which is to
use a synonym of <code class="highlight"><c- k="">typename</c-></code> to declare a type parameter in <code class="highlight"><c- n="">snake_case</c-></code>, and we name our type
parameter in <code class="highlight"><c- n="">PascalCase</c-></code>. When I pointed this out to Herb, he mentioned that this is already
articulated in §1.1.3.</p>
   <h3 class="heading settled" data-level="1.2" id="whos-co-authoring-it"><span class="secno">1.2. </span><span class="content">Who’s co-authoring it?</span><a class="self-link" href="#whos-co-authoring-it"></a></h3>
   <p>All of the major authors for both concepts and ranges have co-authored P1754, and are unanimous that
this should happen. Being the architects for these features, it is likely that they collectively and
individually have the most experience of anyone with these names. We should solemnly acknowledge
this experience, and at least <em>heavily</em> experiment with their proposal before digging our heels in
and claiming that the aberration in the standard library should remain status quo.</p>
   <h2 class="heading settled" data-level="2" id="thoughts-on-the-new-concept-names"><span class="secno">2. </span><span class="content">Thoughts on the new concept names</span><a class="self-link" href="#thoughts-on-the-new-concept-names"></a></h2>
   <p>P1754 also seeks to alter the spelling of a few concepts, as seen below.</p>
   <table>
    <tbody>
     <tr>
      <th>Current
      </th><th>With P1754<br>
     </th></tr><tr>
      <td><code class="highlight"><c- n="">Same</c-></code>
      </td><td><code class="highlight"><c- n="">same_as</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">CommonReference</c-></code>
      </td><td><code class="highlight"><c- n="">has_common_reference</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">Common</c-></code>
      </td><td><code class="highlight"><c- n="">has_common_type</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">Assignable</c-></code>
      </td><td><code class="highlight"><c- n="">assignable_from</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">Boolean</c-></code>
      </td><td><code class="highlight"><c- n="">boolean_type</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">StrictTotallyOrdered</c-><c- p="">(</c-><c- n="">With</c-><c- p="">)</c-></code>
      </td><td><code class="highlight"><c- n="">totally_ordered</c-><c- p="">(</c-><c- n="">_with</c-><c- p="">)</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">StrictWeakOrder</c-></code>
      </td><td><code class="highlight"><c- n="">weak_order</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">Iterator</c-></code>
      </td><td><code class="highlight"><c- n="">iterator_type</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- p="">(</c-><c- n="">Sized</c-><c- p="">)</c-><c- n="">Sentinel</c-></code><br>
      </td><td><code class="highlight"><c- p="">(</c-><c- n="">sized_</c-><c- p="">)</c-><c- n="">sentinel_for</c-></code><br>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">IndirectlyMovable</c-><c- p="">(</c-><c- n="">Storable</c-><c- p="">)</c-></code>
      </td><td><code class="highlight"><c- n="">indirect_movable</c-><c- p="">(</c-><c- n="">_storable</c-><c- p="">)</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">IndirectlyCopyable</c-><c- p="">(</c-><c- n="">Storable</c-><c- p="">)</c-></code>
      </td><td><code class="highlight"><c- n="">indirect_copyable</c-><c- p="">(</c-><c- n="">_storable</c-><c- p="">)</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">IndirectlySwappable</c-></code>
      </td><td><code class="highlight"><c- n="">indirect_swappable</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">IndirectlyComparable</c-></code>
      </td><td><code class="highlight"><c- n="">indirect_comparable</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">Range</c-></code>
      </td><td><code class="highlight"><c- n="">range_type</c-></code>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">View</c-></code>
      </td><td><code class="highlight"><c- n="">view_type</c-></code>
   </td></tr></tbody></table>
   <h3 class="heading settled" data-level="2.1" id="favoured-renamings"><span class="secno">2.1. </span><span class="content">Favoured renamings</span><a class="self-link" href="#favoured-renamings"></a></h3>
   <p>Reimagining <code class="highlight"><c- n="">Sentinel</c-></code> as <code class="highlight"><c- n="">sentinel_for</c-></code> makes a lot of sense. I also welcome renaming <code class="highlight"><c- n="">Assignable</c-></code> to <code class="highlight"><c- n="">assignable_from</c-></code>, but wonders if <code class="highlight"><c- n="">Constructible</c-></code>'s name should become <code class="highlight"><c- n="">constructible_from</c-></code> for
similar reasons.</p>
   <p>It’s not clear if choosing to rename <code class="highlight"><c- n="">IndirectlyCopyable</c-></code> to <code class="highlight"><c- n="">indirect_copyable</c-></code> was intentional, so
I’d like to provide motivation <em>for</em> this case, in the event it wasn’t. While <code class="highlight"><c- n="">indirectly_copyable</c-></code> reads nicer than <code class="highlight"><c- n="">indirect_copyable</c-></code>, and we could argue that the <code class="highlight"><c- n="">indirect_</c-></code> concepts belong to <a data-link-type="biblio" href="#biblio-indirectcallable">[indirectcallable]</a> and the <code class="highlight"><c- n="">indirectly_</c-></code> concepts live in <a data-link-type="biblio" href="#biblio-algreq">[alg.req]</a>, I think this is just
happenstance. For example, when describing the requirements for the C++17 numeric algorithms, I
needed to define a concept called <code class="highlight"><c- n="">commutative_invocable</c-></code>, which has an indirect callable
counterpart that would likely live in [indirectcallable]. It’s very tempting to name this <code class="highlight"><c- n="">indirectly_commutative</c-></code> instead of <code class="highlight"><c- n="">indirect_commutative_invocable</c-></code>, which immediately blurs the
line between what’s <code class="highlight"><c- n="">indirect_</c-></code> and what’s <code class="highlight"><c- n="">indirectly_</c-></code>. In light of that, to avoid confusion, I
encourage exactly one of <code class="highlight"><c- n="">indirect_</c-></code> or <code class="highlight"><c- n="">indirectly_</c-></code>.</p>
   <h3 class="heading settled" data-level="2.2" id="bikeshedding"><span class="secno">2.2. </span><span class="content">Bikeshedding</span><a class="self-link" href="#bikeshedding"></a></h3>
   <p>There are a few names that I’m not so keen on, and would like to see change, as shown below.</p>
   <table>
    <tbody>
     <tr>
      <th>P1754’s name
      </th><th>My alternative
      </th><th>Comment
     </th></tr><tr>
      <td>
        <code class="highlight"><c- n="">has_common_reference</c-></code>
       <p><code class="highlight"><c- n="">has_common_type</c-></code></p>
      </td><td>
        TBD
       <p><code class="highlight"><c- n="">common_with</c-></code> or <br> <code class="highlight"><c- n="">in_common_with</c-></code> or <br> <code class="highlight"><c- n="">common</c-></code></p>
      </td><td>
        <code class="highlight"><c- n="">has_plus</c-></code> is the epitome of our fears when designing concepts (see the design ideals of <a data-link-type="biblio" href="#biblio-n3351">[N3351]</a>). As such, we should aim to avoid having <code class="highlight"><c- n="">has_anything</c-></code> in the IS*, as it sets a
			dangerous precedent: if <code class="highlight"><c- n="">has_common_type</c-></code> exists, then the case against <code class="highlight"><c- n="">has_plus</c-></code> becomes
			a lot harder.
       <p>Since <code class="highlight"><c- n="">Common</c-></code> refines <code class="highlight"><c- n="">CommonReference</c-></code>, the name <code class="highlight"><c- n="">has_common_type</c-></code> doesn’t really fit:
			it’s a clunky, syntactic name that that implies <code class="highlight"><c- n="">common_type_t</c-><c- o="">&lt;</c-><c- n="">T</c-><c- p="">,</c-> <c- n="">U</c-><c- o="">&gt;</c-></code> is well-formed (and <a data-link-type="biblio" href="#biblio-metatransother-note-a">[meta.trans.other-Note-A]</a> doesn’t concern itself with <code class="highlight"><c- n="">common_reference</c-></code>).</p>
       <p>*At the very least, tangible names shouldn’t be prefixed with <code class="highlight"><c- n="">has_</c-></code> or <code class="highlight"><c- n="">is_</c-></code>, etc., for
			this reason.</p>
     </td></tr><tr>
      <td><code class="highlight"><c- n="">boolean_type</c-></code>
      </td><td> <code class="highlight"><c- n="">boolean</c-></code> or<br> <code class="highlight"><c- n="">context_bool</c-></code> or <code class="highlight"><c- n="">contextually_bool</c-></code> or <code class="highlight"><c- n="">context_boolean</c-></code> or <code class="highlight"><c- n="">contextually_boolean</c-></code> or <code class="highlight"><c- n="">as_if_bool</c-></code>
      </td><td>
        Although the phrase '<code class="highlight"><c- n="">T</c-></code> models <code class="highlight"><c- n="">boolean_type</c-></code>' reads okay, it clashes with existing
			standard type names, such as <code class="highlight"><c- n="">common_type</c-></code>, <code class="highlight"><c- n="">size_type</c-></code>, <code class="highlight"><c- n="">difference_type</c-></code>, <code class="highlight"><c- n="">value_type</c-></code>,
			and <code class="highlight"><c- n="">element_type</c-></code>. Despite there being only a few concepts that end with <code class="highlight"><c- n="">_type</c-></code>, and
			despite most of them not really being necessary outside of defining other concepts, it is
			possible that these concepts are mistaken for types. For example, a user might conclude
			that <code class="highlight"><c- n="">boolean_type</c-></code> is the standard spelling for a user-defined boolean type to avoid
			clashing with any non-standard boolean types. After all, we’ve already set a precedent
			here.
       <p>Corollary: <code class="highlight"><c- n="">boolean_concept</c-></code> and <code class="highlight"><c- n="">boolean_c</c-></code> are 'entity encoding' in identifiers;
			something we try to avoid, and so I discourage this usage too.</p>
       <p>Of the suggested alternatives, I prefer <code class="highlight"><c- n="">contextually_bool</c-></code>.</p>
     </td></tr><tr>
      <td>
        <code class="highlight"><c- n="">iterator_type</c-></code>
       <p><code class="highlight"><c- n="">range_type</c-></code></p>
      </td><td>
        <code class="highlight"><c- n="">ranges</c-><c- o="">::</c-><c- n="">iterator</c-></code>
       <p><code class="highlight"><c- n="">ranges</c-><c- o="">::</c-><c- n="">range</c-></code></p>
      </td><td>
        The <code class="highlight"><c- n="">_type</c-></code> needs to go, for similar reasons as <code class="highlight"><c- n="">boolean_type</c-></code>.
       <p>As P1754 points out, <code class="highlight"><c- n="">std</c-><c- o="">::</c-><c- n="">iterator</c-></code> is already taken by a (deprecated) type. Unless we’re
			willing to remove the current <code class="highlight"><c- n="">std</c-><c- o="">::</c-><c- n="">iterator</c-></code> entity and introduce a new <code class="highlight"><c- n="">std</c-><c- o="">::</c-><c- n="">iterator</c-></code> entity <em>in the same standard</em>, we can’t choose <code class="highlight"><c- n="">std</c-><c- o="">::</c-><c- n="">iterator</c-></code>.</p>
       <p>We can, however, choose <code class="highlight"><c- n="">std</c-><c- o="">::</c-><c- n="">ranges</c-><c- o="">::</c-><c- n="">iterator</c-></code>, which is slightly more compelling, as it
			has similar motivation for being in this namespace as our new algorithms (and we can
			hopefully eject these into namespace <code class="highlight"><c- n="">std</c-></code> one day). This implies that all P0896-introduced
			concepts will also need to be moved across as well.</p>
     </td></tr><tr>
      <td>
        <code class="highlight"><c- n="">view_type</c-></code>
       <p><code class="highlight"><c- n="">viewable_range</c-></code></p>
      </td><td>
        <code class="highlight"><c- n="">viewable_range</c-></code>
       <p><code class="highlight"><c- n="">view_adaptable</c-></code></p>
      </td><td>
        All types that model <code class="highlight"><c- n="">view_type</c-></code> also model <code class="highlight"><c- n="">range</c-></code>, so I find the name <code class="highlight"><c- n="">viewable_range</c-></code> to
			be misleading, since <code class="highlight"><c- n="">viewable_range</c-></code> <em>potentially</em> refines <code class="highlight"><c- n="">view_type</c-></code>. (Note that it’s
			not clear to me how refinement works when disjunctions are involved.)
       <p>From <a data-link-type="biblio" href="#biblio-rangerefinements">[range.refinements]</a>, we see that "the <code class="highlight"><c- n="">ViewableRange</c-></code> concept specifies the
			requirements of a <code class="highlight"><c- n="">Range</c-></code> type that can be converted to a <code class="highlight"><c- n="">View</c-></code> safely". Actual usage of <code class="highlight"><c- n="">ViewableRange</c-></code> shows that it’s used for adapting ranges into views. I suggest that the
			name of <code class="highlight"><c- n="">viewable_range</c-></code> concept reflect this canonical use-case, and is of the opinion
			that <code class="highlight"><c- n="">view_adaptable</c-></code> is more appropriate for this reason.</p>
       <p>This then frees up the name <code class="highlight"><c- n="">viewable_range</c-></code>, which can now be used as the new spelling for <code class="highlight"><c- n="">View</c-></code> (since <code class="highlight"><c- n="">view_type</c-></code> has the same issues as <code class="highlight"><c- n="">boolean_type</c-></code>, etc.). Furthermore, it
			will help cement the idea that all views are ranges.</p>
   </td></tr></tbody></table>
   <h2 class="heading settled" data-level="3" id="conclusion"><span class="secno">3. </span><span class="content">Conclusion</span><a class="self-link" href="#conclusion"></a></h2>
   <p>Some of the names, such as <code class="highlight"><c- n="">has_common_reference</c-></code> and <code class="highlight"><c- n="">range_type</c-></code> are a bit controversial, and
should be reviewed, but I want to make my position unambiguously clear: I do not think that the
current P1754 names should be a showstopper for gaining consensus.</p>
   <p>I understand that there’s concern around renaming these concepts -- and P1754’s authors are also
aware of this -- but I fear that the concern is misplaced. We should embrace the change that P1754
seeks to make, so that our code doesn’t become too squashed, like <code class="highlight"><c- n="">partial_sort_copy</c-></code>.</p>
   <p>At the very least, please write a non-trivial example with the new names, so that you’ve got
something to back you up when you say "I don’t like it".</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="normative"><span class="content">Normative References</span><a class="self-link" href="#normative"></a></h3>
  <dl>
   <dt id="biblio-algreq">[ALG.REQ]
   </dt><dd><a href="http://eel.is/c++draft/alg.req">Common algorithm requirements</a>. URL: <a href="http://eel.is/c++draft/alg.req">http://eel.is/c++draft/alg.req</a>
   </dd><dt id="biblio-indirectcallable">[INDIRECTCALLABLE]
   </dt><dd><a href="http://eel.is/c++draft/indirectcallable">Indirect callable requirements</a>. URL: <a href="http://eel.is/c++draft/indirectcallable">http://eel.is/c++draft/indirectcallable</a>
   </dd><dt id="biblio-metatransother-note-a">[meta.trans.other-Note-A]
   </dt><dd><a href="http://eel.is/c++draft/meta.trans.other#3">[meta.trans.other] Note A</a>. URL: <a href="http://eel.is/c++draft/meta.trans.other#3">http://eel.is/c++draft/meta.trans.other#3</a>
   </dd><dt id="biblio-rangerefinements">[RANGE.REFINEMENTS]
   </dt><dd><a href="http://eel.is/c++draft/range.refinements#4">Other range refinements</a>. URL: <a href="http://eel.is/c++draft/range.refinements#4">http://eel.is/c++draft/range.refinements#4</a>
  </dd></dl>
  <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-n3351">[N3351]
   </dt><dd>Bjarne Stroustrup; Andrew Sutton. <a href="https://wg21.link/n3351">A Concept Design for the STL</a>. URL: <a href="https://wg21.link/n3351">https://wg21.link/n3351</a>
   </dd><dt id="biblio-p1754">[P1754]
   </dt><dd>Herb Sutter; et al. <a href="https://wg21.link/p1754">Rename concepts to standard_case for C++20, while we still can</a>. URL: <a href="https://wg21.link/p1754">https://wg21.link/p1754</a>
  </dd></dl></body></html>
