From 27d0d547ee4d0cb83b678b176c8e96cb78de19b5 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Mon, 17 Jul 2017 19:28:36 +0300
Subject: [PATCH] Add mp_is_set

---
 doc/html/mp11.html         | 53 ++++++++++++++++++---------
 doc/mp11/set.adoc          |  6 ++++
 include/boost/mp11/set.hpp | 19 ++++++++++
 test/Jamfile               |  1 +
 test/mp_is_set.cpp         | 73 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 135 insertions(+), 17 deletions(-)
 create mode 100644 test/mp_is_set.cpp

diff --git a/doc/html/mp11.html b/doc/html/mp11.html
index 90b7f4b..09a461d 100644
--- a/doc/html/mp11.html
+++ b/doc/html/mp11.html
@@ -4,7 +4,7 @@
 <meta charset="UTF-8">
 <!--[if IE]><meta http-equiv="X-UA-Compatible" content="IE=edge"><![endif]-->
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
-<meta name="generator" content="Asciidoctor 1.5.5">
+<meta name="generator" content="Asciidoctor 1.5.6">
 <meta name="author" content="Peter Dimov">
 <title>Boost.Mp11: A C++11 metaprogramming library</title>
 <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700">
@@ -90,13 +90,12 @@ strong,b{font-weight:bold;line-height:inherit}
 small{font-size:60%;line-height:inherit}
 code{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;color:rgba(0,0,0,.9)}
 ul,ol,dl{font-size:1em;line-height:1.6;margin-bottom:1.25em;list-style-position:outside;font-family:inherit}
-ul,ol,ul.no-bullet,ol.no-bullet{margin-left:1.5em}
+ul,ol{margin-left:1.5em}
 ul li ul,ul li ol{margin-left:1.25em;margin-bottom:0;font-size:1em}
 ul.square li ul,ul.circle li ul,ul.disc li ul{list-style:inherit}
 ul.square{list-style-type:square}
 ul.circle{list-style-type:circle}
 ul.disc{list-style-type:disc}
-ul.no-bullet{list-style:none}
 ol li ul,ol li ol{margin-left:1.25em;margin-bottom:0}
 dl dt{margin-bottom:.3125em;font-weight:bold}
 dl dd{margin-bottom:1.25em}
@@ -132,7 +131,11 @@ strong strong{font-weight:400}
 kbd{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;display:inline-block;color:rgba(0,0,0,.8);font-size:.65em;line-height:1.45;background-color:#f7f7f7;border:1px solid #ccc;-webkit-border-radius:3px;border-radius:3px;-webkit-box-shadow:0 1px 0 rgba(0,0,0,.2),0 0 0 .1em white inset;box-shadow:0 1px 0 rgba(0,0,0,.2),0 0 0 .1em #fff inset;margin:0 .15em;padding:.2em .5em;vertical-align:middle;position:relative;top:-.1em;white-space:nowrap}
 .keyseq kbd:first-child{margin-left:0}
 .keyseq kbd:last-child{margin-right:0}
-.menuseq,.menu{color:rgba(0,0,0,.8)}
+.menuseq,.menuref{color:#000}
+.menuseq b:not(.caret),.menuref{font-weight:inherit}
+.menuseq{word-spacing:-.02em}
+.menuseq b.caret{font-size:1.25em;line-height:.8}
+.menuseq i.caret{font-weight:bold;text-align:center;width:.45em}
 b.button:before,b.button:after{position:relative;top:-1px;font-weight:400}
 b.button:before{content:"[";padding:0 3px 0 2px}
 b.button:after{content:"]";padding:0 2px 0 3px}
@@ -199,7 +202,7 @@ table.tableblock>caption.title{white-space:nowrap;overflow:visible;max-width:0}
 table.tableblock #preamble>.sectionbody>.paragraph:first-of-type p{font-size:inherit}
 .admonitionblock>table{border-collapse:separate;border:0;background:none;width:100%}
 .admonitionblock>table td.icon{text-align:center;width:80px}
-.admonitionblock>table td.icon img{max-width:none}
+.admonitionblock>table td.icon img{max-width:initial}
 .admonitionblock>table td.icon .title{font-weight:bold;font-family:"Open Sans","DejaVu Sans",sans-serif;text-transform:uppercase}
 .admonitionblock>table td.content{padding-left:1.125em;padding-right:1.25em;border-left:1px solid #ddddd8;color:rgba(0,0,0,.6)}
 .admonitionblock>table td.content>:last-child>:last-child{margin-bottom:0}
@@ -255,13 +258,13 @@ table.pyhltable .linenodiv{background:none!important;padding-right:0!important}
 table.tableblock{max-width:100%;border-collapse:separate}
 table.tableblock td>.paragraph:last-child p>p:last-child,table.tableblock th>p:last-child,table.tableblock td>p:last-child{margin-bottom:0}
 table.tableblock,th.tableblock,td.tableblock{border:0 solid #dedede}
-table.grid-all th.tableblock,table.grid-all td.tableblock{border-width:0 1px 1px 0}
-table.grid-all tfoot>tr>th.tableblock,table.grid-all tfoot>tr>td.tableblock{border-width:1px 1px 0 0}
-table.grid-cols th.tableblock,table.grid-cols td.tableblock{border-width:0 1px 0 0}
-table.grid-all *>tr>.tableblock:last-child,table.grid-cols *>tr>.tableblock:last-child{border-right-width:0}
-table.grid-rows th.tableblock,table.grid-rows td.tableblock{border-width:0 0 1px 0}
-table.grid-all tbody>tr:last-child>th.tableblock,table.grid-all tbody>tr:last-child>td.tableblock,table.grid-all thead:last-child>tr>th.tableblock,table.grid-rows tbody>tr:last-child>th.tableblock,table.grid-rows tbody>tr:last-child>td.tableblock,table.grid-rows thead:last-child>tr>th.tableblock{border-bottom-width:0}
-table.grid-rows tfoot>tr>th.tableblock,table.grid-rows tfoot>tr>td.tableblock{border-width:1px 0 0 0}
+table.grid-all>thead>tr>.tableblock,table.grid-all>tbody>tr>.tableblock{border-width:0 1px 1px 0}
+table.grid-all>tfoot>tr>.tableblock{border-width:1px 1px 0 0}
+table.grid-cols>*>tr>.tableblock{border-width:0 1px 0 0}
+table.grid-rows>thead>tr>.tableblock,table.grid-rows>tbody>tr>.tableblock{border-width:0 0 1px 0}
+table.grid-rows>tfoot>tr>.tableblock{border-width:1px 0 0 0}
+table.grid-all>*>tr>.tableblock:last-child,table.grid-cols>*>tr>.tableblock:last-child{border-right-width:0}
+table.grid-all>tbody>tr:last-child>.tableblock,table.grid-all>thead:last-child>tr>.tableblock,table.grid-rows>tbody>tr:last-child>.tableblock,table.grid-rows>thead:last-child>tr>.tableblock{border-bottom-width:0}
 table.frame-all{border-width:1px}
 table.frame-sides{border-width:0 1px}
 table.frame-topbot{border-width:1px 0}
@@ -282,10 +285,12 @@ ul li ol{margin-left:1.5em}
 dl dd{margin-left:1.125em}
 dl dd:last-child,dl dd:last-child>:last-child{margin-bottom:0}
 ol>li p,ul>li p,ul dd,ol dd,.olist .olist,.ulist .ulist,.ulist .olist,.olist .ulist{margin-bottom:.625em}
-ul.unstyled,ol.unnumbered,ul.checklist,ul.none{list-style-type:none}
-ul.unstyled,ol.unnumbered,ul.checklist{margin-left:.625em}
-ul.checklist li>p:first-child>.fa-square-o:first-child,ul.checklist li>p:first-child>.fa-check-square-o:first-child{width:1em;font-size:.85em}
-ul.checklist li>p:first-child>input[type="checkbox"]:first-child{width:1em;position:relative;top:1px}
+ul.checklist,ul.none,ol.none,ul.no-bullet,ol.no-bullet,ol.unnumbered,ul.unstyled,ol.unstyled{list-style-type:none}
+ul.no-bullet,ol.no-bullet,ol.unnumbered{margin-left:.625em}
+ul.unstyled,ol.unstyled{margin-left:0}
+ul.checklist{margin-left:.625em}
+ul.checklist li>p:first-child>.fa-square-o:first-child,ul.checklist li>p:first-child>.fa-check-square-o:first-child{width:1.25em;font-size:.8em;position:relative;bottom:.125em}
+ul.checklist li>p:first-child>input[type="checkbox"]:first-child{margin-right:.25em}
 ul.inline{margin:0 auto .625em auto;margin-left:-1.375em;margin-right:0;padding:0;list-style:none;overflow:hidden}
 ul.inline>li{list-style:none;float:left;margin-left:1.375em;display:block}
 ul.inline>li>*{display:block}
@@ -302,7 +307,8 @@ ol.lowergreek{list-style-type:lower-greek}
 td.hdlist1,td.hdlist2{vertical-align:top;padding:0 .625em}
 td.hdlist1{font-weight:bold;padding-bottom:1.25em}
 .literalblock+.colist,.listingblock+.colist{margin-top:-.5em}
-.colist>table tr>td:first-of-type{padding:0 .75em;line-height:1}
+.colist>table tr>td:first-of-type{padding:.4em .75em 0 .75em;line-height:1;vertical-align:top}
+.colist>table tr>td:first-of-type img{max-width:initial}
 .colist>table tr>td:last-of-type{padding:.25em 0}
 .thumb,.th{line-height:0;display:inline-block;border:solid 4px #fff;-webkit-box-shadow:0 0 0 1px #ddd;box-shadow:0 0 0 1px #ddd}
 .imageblock.left,.imageblock[style*="float: left"]{margin:.25em .625em 1.25em 0}
@@ -365,6 +371,7 @@ div.unbreakable{page-break-inside:avoid}
 .yellow{color:#bfbf00}
 .yellow-background{background-color:#fafa00}
 span.icon>.fa{cursor:default}
+a span.icon>.fa{cursor:inherit}
 .admonitionblock td.icon [class^="fa icon-"]{font-size:2.5em;text-shadow:1px 1px 2px rgba(0,0,0,.5);cursor:default}
 .admonitionblock td.icon .icon-note:before{content:"\f05a";color:#19407c}
 .admonitionblock td.icon .icon-tip:before{content:"\f0eb";text-shadow:1px 1px 2px rgba(155,155,0,.8);color:#111}
@@ -543,6 +550,7 @@ body.book #toc,body.book #preamble,body.book h1.sect0,body.book .sect1>h2{page-b
 </li>
 <li><a href="#set">Set Operations, &lt;boost/mp11/set.hpp&gt;</a>
 <ul class="sectlevel3">
+<li><a href="#mp_is_set_s">mp_is_set&lt;S&gt;</a></li>
 <li><a href="#mp_set_contains_s_v">mp_set_contains&lt;S, V&gt;</a></li>
 <li><a href="#mp_set_push_back_s_t">mp_set_push_back&lt;S, T&#8230;&#8203;&gt;</a></li>
 <li><a href="#mp_set_push_front_s_t">mp_set_push_front&lt;S, T&#8230;&#8203;&gt;</a></li>
@@ -3381,6 +3389,17 @@ Only <code>constexpr</code> on C++14 and higher.</p>
 <p>A set is a list whose elements are unique.</p>
 </div>
 <div class="sect3">
+<h4 id="mp_is_set_s">mp_is_set&lt;S&gt;</h4>
+<div class="literalblock">
+<div class="content">
+<pre>template&lt;class S&gt; using mp_is_set = /*...*/;</pre>
+</div>
+</div>
+<div class="paragraph">
+<p><code>mp_is_set&lt;S&gt;</code> is <code>mp_true</code> if <code>S</code> is a set, <code>mp_false</code> otherwise.</p>
+</div>
+</div>
+<div class="sect3">
 <h4 id="mp_set_contains_s_v">mp_set_contains&lt;S, V&gt;</h4>
 <div class="literalblock">
 <div class="content">
diff --git a/doc/mp11/set.adoc b/doc/mp11/set.adoc
index e8d708f..d57ec73 100644
--- a/doc/mp11/set.adoc
+++ b/doc/mp11/set.adoc
@@ -15,6 +15,12 @@ http://www.boost.org/LICENSE_1_0.txt
 
 A set is a list whose elements are unique.
 
+## mp_is_set<S>
+
+    template<class S> using mp_is_set = /*...*/;
+
+`mp_is_set<S>` is `mp_true` if `S` is a set, `mp_false` otherwise.
+
 ## mp_set_contains<S, V>
 
     template<class S, class V> using mp_set_contains = /*...*/;
diff --git a/include/boost/mp11/set.hpp b/include/boost/mp11/set.hpp
index a3b3b38..cd77d64 100644
--- a/include/boost/mp11/set.hpp
+++ b/include/boost/mp11/set.hpp
@@ -9,6 +9,7 @@
 //  http://www.boost.org/LICENSE_1_0.txt
 
 #include <boost/mp11/utility.hpp>
+#include <boost/mp11/detail/mp_list.hpp>
 #include <type_traits>
 
 namespace boost
@@ -78,6 +79,24 @@ template<template<class...> class L, class... U, class T1, class... T> struct mp
 
 template<class S, class... T> using mp_set_push_front = typename detail::mp_set_push_front_impl<S, T...>::type;
 
+// mp_is_set<S>
+namespace detail
+{
+
+template<class S> struct mp_is_set_impl
+{
+    using type = mp_false;
+};
+
+template<template<class...> class L, class... T> struct mp_is_set_impl<L<T...>>
+{
+    using type = mp_to_bool<std::is_same<mp_list<T...>, mp_set_push_back<mp_list<>, T...>>>;
+};
+
+} // namespace detail
+
+template<class S> using mp_is_set = typename detail::mp_is_set_impl<S>::type;
+
 } // namespace mp11
 } // namespace boost
 
diff --git a/test/Jamfile b/test/Jamfile
index 05eefac..3396702 100644
--- a/test/Jamfile
+++ b/test/Jamfile
@@ -106,6 +106,7 @@ compile construct_from_tuple_cx.cpp : $(REQ) ;
 run mp_set_contains.cpp : : : $(REQ) ;
 run mp_set_push_back.cpp : : : $(REQ) ;
 run mp_set_push_front.cpp : : : $(REQ) ;
+run mp_is_set.cpp : : : $(REQ) ;
 
 # function
 run mp_all.cpp : : : $(REQ) ;
diff --git a/test/mp_is_set.cpp b/test/mp_is_set.cpp
new file mode 100644
index 0000000..8657dc4
--- /dev/null
+++ b/test/mp_is_set.cpp
@@ -0,0 +1,73 @@
+
+// Copyright 2017 Peter Dimov.
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+
+
+#include <boost/mp11/set.hpp>
+#include <boost/mp11/list.hpp>
+#include <boost/mp11/utility.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+#include <type_traits>
+#include <tuple>
+#include <utility>
+
+int main()
+{
+    using boost::mp11::mp_list;
+    using boost::mp11::mp_is_set;
+    using boost::mp11::mp_true;
+    using boost::mp11::mp_false;
+
+    {
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<void>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<int>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<char[]>, mp_false>));
+    }
+
+    {
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<>>, mp_true>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void>>, mp_true>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void, void>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void, void, void>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void, void, void, void>>, mp_false>));
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void, int>>, mp_true>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void, int, void>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void, int, int>>, mp_false>));
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void, int, char[]>>, mp_true>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void, int, char[], void>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void, int, char[], int>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<mp_list<void, int, char[], char[]>>, mp_false>));
+    }
+
+    {
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<>>, mp_true>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void>>, mp_true>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void, void>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void, void, void>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void, void, void, void>>, mp_false>));
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void, int>>, mp_true>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void, int, void>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void, int, int>>, mp_false>));
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void, int, char[]>>, mp_true>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void, int, char[], void>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void, int, char[], int>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::tuple<void, int, char[], char[]>>, mp_false>));
+    }
+
+    {
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::pair<void, void>>, mp_false>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::pair<void, int>>, mp_true>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::pair<int, void>>, mp_true>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<mp_is_set<std::pair<int, int>>, mp_false>));
+    }
+
+    return boost::report_errors();
+}