boost-react-native-bundle

<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Class template unordered_set</title> <link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> <link rel="up" href="../unordered/reference.html#header.boost.unordered_set_hpp" title="Header <boost/unordered_set.hpp>"> <link rel="prev" href="../unordered/reference.html" title="Reference"> <link rel="next" href="unordered_multiset.html" title="Class template unordered_multiset"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> <td align="center"><a href="../../../index.html">Home</a></td> <td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="../unordered/reference.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../unordered/reference.html#header.boost.unordered_set_hpp"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="unordered_multiset.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="refentry"> <a name="boost.unordered_set"></a><div class="titlepage"></div> <div class="refnamediv"> <h2>Class template unordered_set</h2> boost::unordered_set — An unordered associative container that stores unique values. </div> <h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> <div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis">// In header: <<a class="link" href="../unordered/reference.html#header.boost.unordered_set_hpp" title="Header <boost/unordered_set.hpp>">boost/unordered_set.hpp</a>> template<typename Value, typename Hash = boost::hash<Value>, typename Pred = std::equal_to<Value>, typename Alloc = std::allocator<Value> > class <a class="link" href="unordered_set.html" title="Class template unordered_set">unordered_set</a> { public: // <a class="link" href="unordered_set.html#boost.unordered_settypes">types</a> typedef Value <a name="boost.unordered_set.key_type"></a>key_type; typedef Value <a name="boost.unordered_set.value_type"></a>value_type; typedef Hash <a name="boost.unordered_set.hasher"></a>hasher; typedef Pred <a name="boost.unordered_set.key_equal"></a>key_equal; typedef Alloc <a name="boost.unordered_set.allocator_type"></a>allocator_type; typedef typename allocator_type::pointer <a class="link" href="unordered_set.html#boost.unordered_set.pointer">pointer</a>; typedef typename allocator_type::const_pointer <a class="link" href="unordered_set.html#boost.unordered_set.const_pointer">const_pointer</a>; typedef value_type& <a name="boost.unordered_set.reference"></a>reference; // lvalue of value_type. typedef value_type const& <a name="boost.unordered_set.const_reference"></a>const_reference; // const lvalue of value_type. typedef implementation-defined <a class="link" href="unordered_set.html#boost.unordered_set.size_type">size_type</a>; typedef implementation-defined <a class="link" href="unordered_set.html#boost.unordered_set.difference_type">difference_type</a>; typedef implementation-defined <a class="link" href="unordered_set.html#boost.unordered_set.iterator">iterator</a>; typedef implementation-defined <a class="link" href="unordered_set.html#boost.unordered_set.const_iterator">const_iterator</a>; typedef implementation-defined <a class="link" href="unordered_set.html#boost.unordered_set.local_iterator">local_iterator</a>; typedef implementation-defined <a class="link" href="unordered_set.html#boost.unordered_set.const_local_iterator">const_local_iterator</a>; // <a class="link" href="unordered_set.html#boost.unordered_setconstruct-copy-destruct">construct/copy/destruct</a> explicit <a class="link" href="unordered_set.html#idp302733248-bb">unordered_set</a>(size_type = implementation-defined, hasher const& = hasher(), key_equal const& = key_equal(), allocator_type const& = allocator_type()); template<typename InputIterator> <a class="link" href="unordered_set.html#idp216313968-bb">unordered_set</a>(InputIterator, InputIterator, size_type = implementation-defined, hasher const& = hasher(), key_equal const& = key_equal(), allocator_type const& = allocator_type()); <a class="link" href="unordered_set.html#idp216328208-bb">unordered_set</a>(unordered_set const&); <a class="link" href="unordered_set.html#idp216332688-bb">unordered_set</a>(unordered_set &&); explicit <a class="link" href="unordered_set.html#idp216338784-bb">unordered_set</a>(Allocator const&); <a class="link" href="unordered_set.html#idp104483536-bb">unordered_set</a>(unordered_set const&, Allocator const&); <a class="link" href="unordered_set.html#idp104488096-bb">~unordered_set</a>(); unordered_set& <a class="link" href="unordered_set.html#idp104489408-bb">operator=</a>(unordered_set const&); unordered_set& <a class="link" href="unordered_set.html#idp104495088-bb">operator=</a>(unordered_set &&); allocator_type <a class="link" href="unordered_set.html#idp104501936-bb">get_allocator</a>() const; // <a class="link" href="unordered_set.html#idp104503376-bb">size and capacity</a> bool <a class="link" href="unordered_set.html#idp104503936-bb">empty</a>() const; size_type <a class="link" href="unordered_set.html#idp104506560-bb">size</a>() const; size_type <a class="link" href="unordered_set.html#idp104509792-bb">max_size</a>() const; // <a class="link" href="unordered_set.html#idp104512384-bb">iterators</a> iterator <a class="link" href="unordered_set.html#idp104513504-bb">begin</a>(); const_iterator <a class="link" href="unordered_set.html#idp104514080-bb">begin</a>() const; iterator <a class="link" href="unordered_set.html#idp313561568-bb">end</a>(); const_iterator <a class="link" href="unordered_set.html#idp313562464-bb">end</a>() const; const_iterator <a class="link" href="unordered_set.html#idp313564208-bb">cbegin</a>() const; const_iterator <a class="link" href="unordered_set.html#idp313566240-bb">cend</a>() const; // <a class="link" href="unordered_set.html#idp313568368-bb">modifiers</a> template<typename... Args> std::pair<iterator, bool> <a class="link" href="unordered_set.html#idp313568928-bb">emplace</a>(Args&&...); template<typename... Args> iterator <a class="link" href="unordered_set.html#idp313583536-bb">emplace_hint</a>(const_iterator, Args&&...); std::pair<iterator, bool> <a class="link" href="unordered_set.html#idp214105296-bb">insert</a>(value_type const&); std::pair<iterator, bool> <a class="link" href="unordered_set.html#idp214114896-bb">insert</a>(value_type&&); iterator <a class="link" href="unordered_set.html#idp214124496-bb">insert</a>(const_iterator, value_type const&); iterator <a class="link" href="unordered_set.html#idp312746320-bb">insert</a>(const_iterator, value_type&&); template<typename InputIterator> void <a class="link" href="unordered_set.html#idp312757584-bb">insert</a>(InputIterator, InputIterator); iterator <a class="link" href="unordered_set.html#idp312768688-bb">erase</a>(const_iterator); size_type <a class="link" href="unordered_set.html#idp312209600-bb">erase</a>(key_type const&); iterator <a class="link" href="unordered_set.html#idp312215920-bb">erase</a>(const_iterator, const_iterator); void <a class="link" href="unordered_set.html#idp312224896-bb">quick_erase</a>(const_iterator); void <a class="link" href="unordered_set.html#idp312232560-bb">erase_return_void</a>(const_iterator); void <a class="link" href="unordered_set.html#idp312240224-bb">clear</a>(); void <a class="link" href="unordered_set.html#idp304200752-bb">swap</a>(unordered_set&); // <a class="link" href="unordered_set.html#idp304208256-bb">observers</a> hasher <a class="link" href="unordered_set.html#idp304208816-bb">hash_function</a>() const; key_equal <a class="link" href="unordered_set.html#idp304210672-bb">key_eq</a>() const; // <a class="link" href="unordered_set.html#idp304212688-bb">lookup</a> iterator <a class="link" href="unordered_set.html#idp304213808-bb">find</a>(key_type const&); const_iterator <a class="link" href="unordered_set.html#idp304215872-bb">find</a>(key_type const&) const; template<typename CompatibleKey, typename CompatibleHash, typename CompatiblePredicate> iterator <a class="link" href="unordered_set.html#idp304218208-bb">find</a>(CompatibleKey const&, CompatibleHash const&, CompatiblePredicate const&); template<typename CompatibleKey, typename CompatibleHash, typename CompatiblePredicate> const_iterator <a class="link" href="unordered_set.html#idp304224752-bb">find</a>(CompatibleKey const&, CompatibleHash const&, CompatiblePredicate const&) const; size_type <a class="link" href="unordered_set.html#idp312883504-bb">count</a>(key_type const&) const; std::pair<iterator, iterator> <a class="link" href="unordered_set.html#idp312887984-bb">equal_range</a>(key_type const&); std::pair<const_iterator, const_iterator> <a class="link" href="unordered_set.html#idp312890064-bb">equal_range</a>(key_type const&) const; // <a class="link" href="unordered_set.html#idp312895712-bb">bucket interface</a> size_type <a class="link" href="unordered_set.html#idp312896272-bb">bucket_count</a>() const; size_type <a class="link" href="unordered_set.html#idp312898608-bb">max_bucket_count</a>() const; size_type <a class="link" href="unordered_set.html#idp312900912-bb">bucket_size</a>(size_type) const; size_type <a class="link" href="unordered_set.html#idp312906352-bb">bucket</a>(key_type const&) const; local_iterator <a class="link" href="unordered_set.html#idp312912032-bb">begin</a>(size_type); const_local_iterator <a class="link" href="unordered_set.html#idp312914096-bb">begin</a>(size_type) const; local_iterator <a class="link" href="unordered_set.html#idp304577184-bb">end</a>(size_type); const_local_iterator <a class="link" href="unordered_set.html#idp304579248-bb">end</a>(size_type) const; const_local_iterator <a class="link" href="unordered_set.html#idp304584688-bb">cbegin</a>(size_type) const; const_local_iterator <a class="link" href="unordered_set.html#idp304590240-bb">cend</a>(size_type); // <a class="link" href="unordered_set.html#idp304595792-bb">hash policy</a> float <a class="link" href="unordered_set.html#idp304596352-bb">load_factor</a>() const; float <a class="link" href="unordered_set.html#idp304598656-bb">max_load_factor</a>() const; void <a class="link" href="unordered_set.html#idp304600960-bb">max_load_factor</a>(float); void <a class="link" href="unordered_set.html#idp304604608-bb">rehash</a>(size_type); void <a class="link" href="unordered_set.html#idp304609776-bb">reserve</a>(size_type); }; // <a class="link" href="unordered_set.html#idp304614272-bb">Equality Comparisons</a> template<typename Value, typename Hash, typename Pred, typename Alloc> bool <a class="link" href="unordered_set.html#boost.unordered_set.operator==_idp304614832">operator==</a>(unordered_set<Value, Hash, Pred, Alloc> const&, unordered_set<Value, Hash, Pred, Alloc> const&); template<typename Value, typename Hash, typename Pred, typename Alloc> bool <a class="link" href="unordered_set.html#boost.unordered_set.operator!=_idp304626304">operator!=</a>(unordered_set<Value, Hash, Pred, Alloc> const&, unordered_set<Value, Hash, Pred, Alloc> const&); // <a class="link" href="unordered_set.html#idp312243552-bb">swap</a> template<typename Value, typename Hash, typename Pred, typename Alloc> void <a class="link" href="unordered_set.html#boost.unordered_set.swap_idp312244112">swap</a>(unordered_set<Value, Hash, Pred, Alloc>&, unordered_set<Value, Hash, Pred, Alloc>&);</pre></div> <div class="refsect1"> <a name="idp517421760"></a><h2>Description</h2> Template Parameters <div class="informaltable"><table class="table"> <colgroup> <col> <col> </colgroup> <tbody> <tr> <td>Value</td> <td> <code class="computeroutput">Value</code> must be <code class="computeroutput">Erasable</code> from the container (i.e. <code class="computeroutput">allocator_traits</code> can <code class="computeroutput">destroy</code> it). </td> </tr> <tr> <td>Hash</td> <td>A unary function object type that acts a hash function for a <code class="computeroutput">Value</code>. It takes a single argument of type <code class="computeroutput">Value</code> and returns a value of type std::size_t.</td> </tr> <tr> <td>Pred</td> <td>A binary function object that implements an equivalence relation on values of type <code class="computeroutput">Value</code>. A binary function object that induces an equivalence relation on values of type <code class="computeroutput">Value</code>. It takes two arguments of type <code class="computeroutput">Value</code> and returns a value of type bool.</td> </tr> <tr> <td>Alloc</td> <td>An allocator whose value type is the same as the container's value type.</td> </tr> </tbody> </table></div> The elements are organized into buckets. Keys with the same hash code are stored in the same bucket. The number of buckets can be automatically increased by a call to insert, or as the result of calling rehash. <div class="refsect2"> <a name="idp517436640"></a><h3> <a name="boost.unordered_settypes"></a><code class="computeroutput">unordered_set</code> public types</h3> <div class="orderedlist"><ol class="orderedlist" type="1"> <li class="listitem"> typedef typename allocator_type::pointer <a name="boost.unordered_set.pointer"></a>pointer; <code class="computeroutput">value_type*</code> if <code class="computeroutput">allocator_type::pointer</code> is not defined. </li> <li class="listitem"> typedef typename allocator_type::const_pointer <a name="boost.unordered_set.const_pointer"></a>const_pointer; <code class="computeroutput">boost::pointer_to_other<pointer, value_type>::type</code> if <code class="computeroutput">allocator_type::const_pointer</code> is not defined. </li> <li class="listitem"> typedef implementation-defined <a name="boost.unordered_set.size_type"></a>size_type; An unsigned integral type. size_type can represent any non-negative value of difference_type. </li> <li class="listitem"> typedef implementation-defined <a name="boost.unordered_set.difference_type"></a>difference_type; A signed integral type. Is identical to the difference type of iterator and const_iterator. </li> <li class="listitem"> typedef implementation-defined <a name="boost.unordered_set.iterator"></a>iterator; A constant iterator whose value type is value_type. The iterator category is at least a forward iterator. Convertible to const_iterator. </li> <li class="listitem"> typedef implementation-defined <a name="boost.unordered_set.const_iterator"></a>const_iterator; A constant iterator whose value type is value_type. The iterator category is at least a forward iterator. </li> <li class="listitem"> typedef implementation-defined <a name="boost.unordered_set.local_iterator"></a>local_iterator; An iterator with the same value type, difference type and pointer and reference type as iterator. A local_iterator object can be used to iterate through a single bucket. </li> <li class="listitem"> typedef implementation-defined <a name="boost.unordered_set.const_local_iterator"></a>const_local_iterator; A constant iterator with the same value type, difference type and pointer and reference type as const_iterator. A const_local_iterator object can be used to iterate through a single bucket. </li> </ol></div> </div> <div class="refsect2"> <a name="idp517488048"></a><h3> <a name="boost.unordered_setconstruct-copy-destruct"></a><code class="computeroutput">unordered_set</code> public construct/copy/destruct</h3> <div class="orderedlist"><ol class="orderedlist" type="1"> <li class="listitem"> <pre class="literallayout">explicit <a name="idp302733248-bb"></a>unordered_set(size_type n = implementation-defined, hasher const& hf = hasher(), key_equal const& eq = key_equal(), allocator_type const& a = allocator_type());</pre> Constructs an empty container with at least n buckets, using hf as the hash function, eq as the key equality predicate, a as the allocator and a maximum load factor of 1.0. <div class="variablelist"><table border="0" class="variablelist compact"> <colgroup> <col align="left" valign="top"> <col> </colgroup> <tbody> <tr> <td>Postconditions:</td> <td><code class="computeroutput"><a class="link" href="unordered_set.html#idp104506560-bb">size</a>() == 0</code></td> </tr> <tr> <td>Requires:</td> <td>If the defaults are used, <code class="computeroutput">hasher</code>, <code class="computeroutput">key_equal</code> and <code class="computeroutput">allocator_type</code> need to be <code class="computeroutput">DefaultConstructible</code>. </td> </tr> </tbody> </table></div> </li> <li class="listitem"> <pre class="literallayout">template<typename InputIterator> <a name="idp216313968-bb"></a>unordered_set(InputIterator f, InputIterator l, size_type n = implementation-defined, hasher const& hf = hasher(), key_equal const& eq = key_equal(), allocator_type const& a = allocator_type());</pre> Constructs an empty container with at least n buckets, using hf as the hash function, eq as the key equality predicate, a as the allocator and a maximum load factor of 1.0 and inserts the elements from [f, l) into it. <div class="variablelist"><table border="0" class="variablelist compact"> <colgroup> <col align="left" valign="top"> <col> </colgroup> <tbody><tr> <td>Requires:</td> <td>If the defaults are used, <code class="computeroutput">hasher</code>, <code class="computeroutput">key_equal</code> and <code class="computeroutput">allocator_type</code> need to be <code class="computeroutput">DefaultConstructible</code>. </td> </tr></tbody> </table></div> </li> <li class="listitem"> <pre class="literallayout"><a name="idp216328208-bb"></a>unordered_set(unordered_set const&);</pre> The copy constructor. Copies the contained elements, hash function, predicate, maximum load factor and allocator. If <code class="computeroutput">Allocator::select_on_container_copy_construction</code> exists and has the right signature, the allocator will be constructed from its result. <div class="variablelist"><table border="0" class="variablelist compact"> <colgroup> <col align="left" valign="top"> <col> </colgroup> <tbody><tr> <td>Requires:</td> <td><code class="computeroutput">value_type</code> is copy constructible</td> </tr></tbody> </table></div> </li> <li class="listitem"> <pre class="literallayout"><a name="idp216332688-bb"></a>unordered_set<span class="spe