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| <head> |
| <title>dynamic_bitset<Block, Allocator></title> |
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| <h1>dynamic_bitset<Block, Allocator></h1> |
| <h2>Contents</h2> |
| |
| <dl class="index"> |
| <dt><a href="#description">Description</a></dt> |
| <dt><a href="#synopsis">Synopsis</a></dt> |
| <dt><a href="#definitions">Definitions</a></dt> |
| <dt><a href="#examples">Examples</a></dt> |
| <dt><a href="#rationale">Rationale</a></dt> |
| <dt><a href="#header-files">Header Files</a></dt> |
| <dt><a href="#template-parameters">Template Parameters</a></dt> |
| <dt><a href="#concepts-modeled">Concepts modeled</a></dt> |
| |
| <dt><a href="#type-requirements">Type requirements</a></dt> |
| <dt><a href="#public-base-classes">Public base classes</a></dt> |
| <dt><a href="#nested-type-names">Nested type names</a></dt> |
| <dt><a href="#public-data-members">Public data members</a></dt> |
| <dt><a href="#constructors">Constructors</a></dt> |
| <dt><a href="#destructor">Destructor</a></dt> |
| <dt><a href="#member-functions">Member functions</a></dt> |
| <dt><a href="#non-member-functions">Non-member functions</a></dt> |
| <dt><a href="#exception-guarantees">Exception guarantees</a></dt> |
| |
| <dt><a href="#changes-from-previous-ver"><b>Changes from previous version(s)</b></a></dt> |
| <dt><a href="#see-also">See also</a></dt> |
| <dt><a href="#acknowledgements">Acknowledgements</a></dt> |
| </dl> |
| <h3><a id="description">Description</a></h3> |
| <p>The <tt>dynamic_bitset</tt> class represents a set of bits. It |
| provides accesses to the value of individual bits via an |
| <tt>operator[]</tt> and provides all of the bitwise operators |
| that one can apply to builtin integers, such as |
| <tt>operator&</tt> and <tt>operator<<</tt>. The number |
| of bits in the set is specified at runtime via a parameter to the |
| constructor of the <tt>dynamic_bitset</tt>.</p> |
| |
| <p>The <tt>dynamic_bitset</tt> class is nearly identical to the |
| <a href= |
| "http://www.sgi.com/tech/stl/bitset.html"><tt>std::bitset</tt></a> |
| class. The difference is that the size of the |
| <tt>dynamic_bitset</tt> (the number of bits) is specified at |
| run-time during the construction of a <tt>dynamic_bitset</tt> |
| object, whereas the size of a <tt>std::bitset</tt> is specified |
| at compile-time through an integer template parameter.</p> |
| |
| <p>The main problem that <tt>dynamic_bitset</tt> is designed to |
| solve is that of representing a subset of a finite set. Each bit |
| represents whether an element of the finite set is in the subset |
| or not. As such the bitwise operations of |
| <tt>dynamic_bitset</tt>, such as <tt>operator&</tt> and |
| <tt>operator|</tt>, correspond to set operations, such as |
| intersection and union.</p> |
| <h3><a id ="synopsis">Synopsis</a></h3> |
| <pre> |
| namespace boost { |
| |
| template <typename Block, typename Allocator> |
| class dynamic_bitset |
| { |
| public: |
| typedef Block <a href="#block_type">block_type</a>; |
| typedef Allocator <a href="#allocator_type">allocator_type</a>; |
| typedef <i>implementation-defined</i> <a href="#size_type">size_type</a>; |
| |
| static const int <a href= |
| "#bits_per_block">bits_per_block</a> = <i>implementation-defined</i>; |
| static const size_type <a href= |
| "#npos">npos</a> = <i>implementation-defined</i>; |
| |
| class <a href="#reference">reference</a> |
| { |
| void operator&(); // not defined |
| |
| public: |
| // An automatically generated copy constructor. |
| |
| reference& operator=(bool value); |
| reference& operator=(const reference& rhs); |
| |
| reference& operator|=(bool value); |
| reference& operator&=(bool value); |
| reference& operator^=(bool value); |
| reference& operator-=(bool value); |
| |
| bool operator~() const; |
| operator bool() const; |
| reference& flip(); |
| }; |
| |
| typedef bool <a href="#const_reference">const_reference</a>; |
| |
| explicit <a href= |
| "#cons1">dynamic_bitset</a>(const Allocator& alloc = Allocator()); |
| |
| explicit <a href= |
| "#cons2">dynamic_bitset</a>(size_type num_bits, unsigned long value = 0, |
| const Allocator& alloc = Allocator()); |
| |
| template <typename CharT, typename Traits, typename Alloc> |
| explicit <a href= |
| "#cons3">dynamic_bitset</a>(const std::basic_string<CharT, Traits, Alloc>& s, |
| typename std::basic_string<CharT, Traits, Alloc>::size_type pos = 0, |
| typename std::basic_string<CharT, Traits, Alloc>::size_type n = std::basic_string<CharT, Traits, Alloc>::npos, |
| const Allocator& alloc = Allocator()); |
| |
| template <typename BlockInputIterator> |
| <a href= |
| "#cons4">dynamic_bitset</a>(BlockInputIterator first, BlockInputIterator last, |
| const Allocator& alloc = Allocator()); |
| |
| <a href= |
| "#cons5">dynamic_bitset</a>(const dynamic_bitset& b); |
| |
| void <a href="#swap">swap</a>(dynamic_bitset& b); |
| |
| dynamic_bitset& <a href= |
| "#assign">operator=</a>(const dynamic_bitset& b); |
| |
| allocator_type <a href="#get_allocator">get_allocator()</a> const; |
| |
| void <a href= |
| "#resize">resize</a>(size_type num_bits, bool value = false); |
| void <a href="#clear">clear</a>(); |
| void <a href="#push_back">push_back</a>(bool bit); |
| void <a href="#append1">append</a>(Block block); |
| |
| template <typename BlockInputIterator> |
| void <a href="#append2">append</a>(BlockInputIterator first, BlockInputIterator last); |
| |
| dynamic_bitset& <a href="#op-and-assign">operator&=</a>(const dynamic_bitset& b); |
| dynamic_bitset& <a href="#op-or-assign">operator|=</a>(const dynamic_bitset& b); |
| dynamic_bitset& <a href="#op-xor-assign">operator^=</a>(const dynamic_bitset& b); |
| dynamic_bitset& <a href="#op-sub-assign">operator-=</a>(const dynamic_bitset& b); |
| dynamic_bitset& <a href="#op-sl-assign">operator<<=</a>(size_type n); |
| dynamic_bitset& <a href="#op-sr-assign">operator>>=</a>(size_type n); |
| dynamic_bitset <a href="#op-sl">operator<<</a>(size_type n) const; |
| dynamic_bitset <a href="#op-sr">operator>></a>(size_type n) const; |
| |
| dynamic_bitset& <a href="#set2">set</a>(size_type n, bool val = true); |
| dynamic_bitset& <a href="#set1">set</a>(); |
| dynamic_bitset& <a href="#reset2">reset</a>(size_type n); |
| dynamic_bitset& <a href="#reset1">reset</a>(); |
| dynamic_bitset& <a href="#flip2">flip</a>(size_type n); |
| dynamic_bitset& <a href="#flip1">flip</a>(); |
| bool <a href="#test">test</a>(size_type n) const; |
| bool <a href="#any">any</a>() const; |
| bool <a href="#none">none</a>() const; |
| dynamic_bitset <a href="#op-not">operator~</a>() const; |
| size_type <a href="#count">count</a>() const; |
| |
| reference <a href="#bracket">operator[]</a>(size_type pos); |
| bool <a href="#const-bracket">operator[]</a>(size_type pos) const; |
| |
| unsigned long <a href="#to_ulong">to_ulong</a>() const; |
| |
| size_type <a href="#size">size</a>() const; |
| size_type <a href="#num_blocks">num_blocks</a>() const; |
| size_type <a href="#max_size">max_size</a>() const; |
| bool <a href="#empty">empty</a>() const; |
| |
| bool <a href="#is_subset_of">is_subset_of</a>(const dynamic_bitset& a) const; |
| bool <a href="#is_proper_subset_of">is_proper_subset_of</a>(const dynamic_bitset& a) const; |
| |
| size_type <a href="#find_first">find_first</a>() const; |
| size_type <a href="#find_next">find_next</a>(size_type pos) const; |
| |
| }; |
| |
| |
| template <typename B, typename A> |
| bool <a href= |
| "#op-equal">operator==</a>(const dynamic_bitset<B, A>& a, const dynamic_bitset<B, A>& b); |
| |
| template <typename Block, typename Allocator> |
| bool <a href= |
| "#op-not-equal">operator!=</a>(const dynamic_bitset<Block, Allocator>& a, const dynamic_bitset<Block, Allocator>& b); |
| |
| template <typename B, typename A> |
| bool <a href= |
| "#op-less">operator<</a>(const dynamic_bitset<B, A>& a, const dynamic_bitset<B, A>& b); |
| |
| template <typename Block, typename Allocator> |
| bool <a href= |
| "#op-less-equal">operator<=</a>(const dynamic_bitset<Block, Allocator>& a, const dynamic_bitset<Block, Allocator>& b); |
| |
| template <typename Block, typename Allocator> |
| bool <a href= |
| "#op-greater">operator></a>(const dynamic_bitset<Block, Allocator>& a, const dynamic_bitset<Block, Allocator>& b); |
| |
| template <typename Block, typename Allocator> |
| bool <a href= |
| "#op-greater-equal">operator>=</a>(const dynamic_bitset<Block, Allocator>& a, const dynamic_bitset<Block, Allocator>& b); |
| |
| template <typename Block, typename Allocator> |
| dynamic_bitset<Block, Allocator> |
| <a href= |
| "#op-and">operator&</a>(const dynamic_bitset<Block, Allocator>& b1, const dynamic_bitset<Block, Allocator>& b2); |
| |
| template <typename Block, typename Allocator> |
| dynamic_bitset<Block, Allocator> |
| <a href= |
| "#op-or">operator|</a>(const dynamic_bitset<Block, Allocator>& b1, const dynamic_bitset<Block, Allocator>& b2); |
| |
| template <typename Block, typename Allocator> |
| dynamic_bitset<Block, Allocator> |
| <a href= |
| "#op-xor">operator^</a>(const dynamic_bitset<Block, Allocator>& b1, const dynamic_bitset<Block, Allocator>& b2); |
| |
| template <typename Block, typename Allocator> |
| dynamic_bitset<Block, Allocator> |
| <a href= |
| "#op-sub">operator-</a>(const dynamic_bitset<Block, Allocator>& b1, const dynamic_bitset<Block, Allocator>& b2); |
| |
| template <typename Block, typename Allocator, typename CharT, typename Alloc> |
| void <a href= |
| "#to_string">to_string</a>(const dynamic_bitset<Block, Allocator>& b, |
| std::basic_string<CharT, Alloc>& s); |
| |
| template <typename Block, typename Allocator, typename BlockOutputIterator> |
| void <a href= |
| "#to_block_range">to_block_range</a>(const dynamic_bitset<Block, Allocator>& b, |
| BlockOutputIterator result); |
| |
| template <typename CharT, typename Traits, typename Block, typename Allocator> |
| std::basic_ostream<CharT, Traits>& |
| <a href= |
| "#op-out">operator<<</a>(std::basic_ostream<CharT, Traits>& os, const dynamic_bitset<Block, Allocator>& b); |
| |
| template <typename CharT, typename Traits, typename Block, typename Allocator> |
| std::basic_istream<CharT, Traits>& |
| <a href= |
| "#op-in">operator>></a>(std::basic_istream<CharT, Traits>& is, dynamic_bitset<Block, Allocator>& b); |
| |
| } // namespace boost |
| </pre> |
| |
| <h3><a id="definitions">Definitions</a></h3> |
| |
| <p>Each bit represents either the Boolean value true or false (1 |
| or 0). To <i>set</i> a bit is to assign it 1. To <i>clear</i> or |
| <i>reset</i> a bit is to assign it 0. To <i>flip</i> a bit is to |
| change the value to 1 if it was 0 and to 0 if it was 1. Each bit |
| has a non-negative <i>position</i>. A bitset <tt>x</tt> contains |
| <tt>x.size()</tt> bits, with each bit assigned a unique position |
| in the range <tt>[0,x.size())</tt>. The bit at position 0 is |
| called the <i>least significant bit</i> and the bit at position |
| <tt>size() - 1</tt> is the <i>most significant bit</i>. When |
| converting an instance of <tt>dynamic_bitset</tt> to or from an |
| unsigned long <tt>n</tt>, the bit at position <tt>i</tt> of the |
| bitset has the same value as <tt>(n >> i) & 1</tt>.</p> |
| |
| <h3><a id="examples">Examples</a></h3> |
| |
| <p> |
| <a href="./example/example1.cpp">Example 1</a> (setting |
| and reading some bits) |
| </p> |
| <p> |
| <a href="./example/example2.cpp">Example 2</a> (creating |
| some bitsets from integers) |
| </p> |
| |
| <p> |
| <a href="./example/example3.cpp">Example 3</a> (performing |
| input/output and some bitwise operations). |
| </p> |
| |
| |
| <h3><a id="rationale">Rationale</a></h3> |
| <p> |
| <tt>dynamic_bitset</tt> is not a <a href= |
| "http://www.sgi.com/tech/stl/Container.html">Container</a> and |
| does not provide iterators for the following reason: |
| </p> |
| |
| <ul> |
| <li>A container with a proxy <tt>reference</tt> type can not |
| fulfill the container requirements as specified in the C++ |
| standard (unless one resorts to strange iterator semantics). |
| <tt>std::vector<bool></tt> has a proxy <tt>reference</tt> |
| type and does not fulfill the container requirements and as a |
| result has caused many problems. One common problem is when |
| people try to use iterators from <tt>std::vector<bool></tt> |
| with a Standard algorithm such as <tt>std::search</tt>. The |
| <tt>std::search</tt> requirements say that the iterator must be a |
| <a href= |
| "http://www.sgi.com/tech/stl/ForwardIterator.html">Forward |
| Iterator</a>, but the <tt>std::vector<bool>::iterator</tt> |
| does not meet this requirement because of the proxy reference. |
| Depending on the implementation, they may or not be a compile |
| error or even a run-time error due to this misuse. For further |
| discussion of the problem see <i>Effective STL</i> by Scott |
| Meyers). So <tt>dynamic_bitset</tt> tries to avoid these problems |
| by not pretending to be a container.</li> |
| </ul> |
| |
| <p>Some people prefer the name "toggle" to "flip". The name |
| "flip" was chosen because that is the name used in <a href= |
| "http://www.sgi.com/tech/stl/bitset.html"><tt>std::bitset</tt></a>. |
| In fact, most of the function names for <tt>dynamic_bitset</tt> |
| were chosen for this reason.</p> |
| |
| <p><tt>dynamic_bitset</tt> does not throw exceptions when a |
| precondition is violated (as is done in <tt>std::bitset</tt>). |
| Instead <tt>assert</tt> is used. See the guidelines for <a href= |
| "http://www.boost.org/more/error_handling.html">Error and Exception Handling</a> |
| for the explanation.</p> |
| |
| <h3><a id="header-files">Header Files</a></h3> |
| |
| <p>The class <tt>dynamic_bitset</tt> is defined in the header <a |
| href= |
| "../../boost/dynamic_bitset.hpp">boost/dynamic_bitset.hpp</a>. |
| Also, there is a forward declaration for <tt>dynamic_bitset</tt> |
| in the header <a href= |
| "../../boost/dynamic_bitset_fwd.hpp">boost/dynamic_bitset_fwd.hpp</a>.</p> |
| |
| <h3><a id="template-parameters">Template parameters</a></h3> |
| |
| <table summary= |
| "Describes the meaning of the template parameters and lists their corresponding default arguments"> |
| <tr> |
| <th>Parameter</th> |
| <th>Description</th> |
| <th>Default</th> |
| </tr> |
| <tr> |
| <td><tt>Block</tt></td> |
| <td>The integer type in which the bits are stored.</td> |
| <td><tt>unsigned long</tt></td> |
| </tr> |
| <tr> |
| |
| <td><tt>Allocator</tt></td> |
| <td>The allocator type used for all internal memory management.</td> |
| <td><tt>std::allocator<Block></tt></td> |
| </tr> |
| </table> |
| <h3><a id="concepts-modeled">Concepts Modeled</a></h3> |
| <a href= |
| "http://www.sgi.com/tech/stl/Assignable.html">Assignable</a>, <a |
| href= |
| "http://www.sgi.com/tech/stl/DefaultConstructible.html">Default |
| Constructible</a>, <a href= |
| "http://www.sgi.com/tech/stl/EqualityComparable.html">Equality |
| Comparable</a>, <a href= |
| "http://www.sgi.com/tech/stl/LessThanComparable.html">LessThan |
| Comparable</a>. |
| |
| <h3><a id="type-requirements">Type requirements</a></h3> |
| |
| <tt>Block</tt> is an unsigned integer type. <tt>Allocator</tt> |
| satisfies the Standard requirements for an allocator. |
| |
| <h3><a id="public-base-classes">Public base classes</a></h3> |
| |
| None. |
| <h3><a id="nested-type-names">Nested type names</a></h3> |
| <hr /> |
| |
| <pre> |
| <a id="reference">dynamic_bitset::reference</a> |
| </pre> |
| |
| <p>A proxy class that acts as a reference to a single bit. It |
| contains an assignment operator, a conversion to <tt>bool</tt>, |
| an <tt>operator~</tt>, and a member function <tt>flip</tt>. It |
| exists only as a helper class for <tt>dynamic_bitset</tt>'s |
| <tt>operator[]</tt>. The following table describes the valid |
| operations on the <tt>reference</tt> type. Assume that <tt>b</tt> |
| is an instance of <tt>dynamic_bitset</tt>, <tt>i, j</tt> are of |
| <tt>size_type</tt> and in the range <tt>[0,b.size())</tt>. Also, |
| note that when we write <tt>b[i]</tt> we mean an object of type |
| <tt>reference</tt> that was initialized from <tt>b[i]</tt>. The |
| variable <tt>x</tt> is a <tt>bool</tt>.</p> |
| |
| <table border="1" summary= |
| "Semantics of several expressions involving usage of dynamic_bitset::reference"> |
| <tr> |
| <th>Expression</th> |
| <th>Semantics</th> |
| </tr> |
| <tr> |
| <td><tt>x = b[i]</tt></td> |
| <td>Assign the ith bit of <tt>b</tt> to <tt>x</tt>.</td> |
| </tr> |
| <tr> |
| <td><tt>(bool)b[i]</tt></td> |
| <td>Return the ith bit of <tt>b</tt>.</td> |
| </tr> |
| <tr> |
| <td><tt>b[i] = x</tt></td> |
| <td>Set the ith bit of <tt>b</tt> to the value of <tt>x</tt> and |
| return <tt>b[i]</tt>.</td> |
| </tr> |
| <tr> |
| <td><tt>b[i] |= x</tt></td> |
| <td>Or the ith bit of <tt>b</tt> with the value of <tt>x</tt> and |
| return <tt>b[i]</tt>.</td> |
| </tr> |
| <tr> |
| <td><tt>b[i] &= x</tt></td> |
| <td>And the ith bit of <tt>b</tt> with the value of <tt>x</tt> |
| and return <tt>b[i]</tt>.</td> |
| </tr> |
| |
| <tr> |
| <td><tt>b[i] ^= x</tt></td> |
| <td>Exclusive-Or the ith bit of <tt>b</tt> with the value of |
| <tt>x</tt> and return <tt>b[i]</tt>.</td> |
| </tr> |
| |
| <tr> |
| <td><tt>b[i] -= x</tt></td> |
| <td>If <tt>x==true</tt>, clear the ith bit of <tt>b</tt>. Returns |
| <tt>b[i]</tt>.</td> |
| </tr> |
| |
| <tr> |
| <td><tt>b[i] = b[j]</tt></td> |
| <td>Set the ith bit of <tt>b</tt> to the value of the jth bit of |
| <tt>b</tt> and return <tt>b[i]</tt>.</td> |
| </tr> |
| |
| <tr> |
| <td><tt>b[i] |= b[j]</tt></td> |
| <td>Or the ith bit of <tt>b</tt> with the jth bit of <tt>b</tt> |
| and return <tt>b[i]</tt>.</td> |
| </tr> |
| |
| <tr> |
| <td><tt>b[i] &= b[j]</tt></td> |
| <td>And the ith bit of <tt>b</tt> with the jth bit of <tt>b</tt> and return <tt>b[i]</tt>.</td> |
| </tr> |
| <tr> |
| <td><tt>b[i] ^= b[j]</tt></td> |
| <td>Exclusive-Or the ith bit of <tt>b</tt> with the jth bit of <tt>b</tt> and return <tt>b[i]</tt>.</td> |
| |
| </tr> |
| <tr> |
| <td><tt>b[i] -= b[j]</tt></td> |
| <td>If the jth bit of <tt>b</tt> is set, clear the ith bit of <tt>b</tt>. Returns <tt>b[i]</tt>.</td> |
| </tr> |
| <tr> |
| <td><tt>x = ~b[i]</tt></td> |
| |
| <td>Assign the opposite of the ith bit of <tt>b</tt> to <tt>x</tt>.</td> |
| </tr> |
| <tr> |
| <td><tt>(bool)~b[i]</tt></td> |
| <td>Return the opposite of the ith bit of <tt>b</tt>.</td> |
| </tr> |
| <tr> |
| |
| <td><tt>b[i].flip()</tt></td> |
| <td>Flip the ith bit of <tt>b</tt> and return <tt>b[i]</tt>.</td> |
| </tr> |
| </table> |
| <hr /> |
| <pre> |
| <a id="const_reference">dynamic_bitset::const_reference</a> |
| </pre> |
| The type <tt>bool</tt>. |
| |
| <pre> |
| <a id="size_type">dynamic_bitset::size_type</a> |
| </pre> |
| The unsigned integer type for representing the size of the bit set. |
| |
| <pre> |
| <a id="block_type">dynamic_bitset::block_type</a> |
| </pre> |
| The same type as <tt>Block</tt>. |
| |
| <pre> |
| <a id="allocator_type">dynamic_bitset::allocator_type;</a> |
| </pre> |
| The same type as <tt>Allocator</tt>. |
| |
| |
| <hr /> |
| <h3><a id="public-data-members">Public data members</a></h3> |
| |
| <pre> |
| <a id="bits_per_block">dynamic_bitset::bits_per_block</a> |
| </pre> |
| The number of bits the type <tt>Block</tt> uses to represent values, |
| excluding any padding bits. Numerically equal |
| to <tt>std::numeric_limits<Block>::digits</tt>. |
| |
| <pre> |
| <a id="npos">dynamic_bitset::npos</a> |
| </pre> |
| The maximum value of <tt>size_type</tt>. |
| |
| <hr /> |
| <h3><a id="constructors">Constructors</a></h3> |
| |
| <hr /> |
| <pre> |
| <a id= |
| "cons1">dynamic_bitset</a>(const Allocator& alloc = Allocator()) |
| </pre> |
| |
| <b>Effects:</b> Constructs a bitset of size zero. A copy of the |
| <tt>alloc</tt> object will be used in subsequent bitset |
| operations such as <tt>resize</tt> to allocate memory.<br /> |
| <b>Postconditions:</b> <tt>this->size() == 0</tt>.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if |
| <tt>Allocator=std::allocator</tt>).<br /> |
| (Required by <a href= |
| "http://www.sgi.com/tech/stl/DefaultConstructible.html">Default |
| Constructible</a>.) |
| |
| <hr /> |
| <pre> |
| <a id="cons2">dynamic_bitset</a>(size_type num_bits, |
| unsigned long value = 0, |
| const Allocator& alloc = Allocator()) |
| </pre> |
| |
| <b>Effects:</b> Constructs a bitset from an integer. The first |
| <tt>M</tt> bits are initialized to the corresponding bits in |
| <tt>value</tt> and all other bits, if any, to zero (where <tt>M = |
| min(num_bits, std::numeric_limits<unsigned long>::digits)</tt>). A copy of |
| the <tt>alloc</tt> object will be used in subsequent bitset |
| operations such as <tt>resize</tt> to allocate memory. Note that, e.g., the |
| following |
| <br /><br /> |
| <tt> |
| dynamic_bitset b<>( 16, 7 ); |
| </tt><br /><br /> |
| will match the <a href="#cons4">constructor from an iterator range</a> (not this |
| one), but the underlying implementation will still "do the right thing" and |
| construct a bitset of 16 bits, from the value 7. |
| <br /> |
| <b>Postconditions:</b> |
| |
| <ul> |
| <li><tt>this->size() == num_bits</tt></li> |
| |
| <li>For all <tt>i</tt> in the range <tt>[0,M)</tt>, |
| <tt>(*this)[i] == (value >> i) & 1</tt>.</li> |
| |
| <li>For all <tt>i</tt> in the range <tt>[M,num_bits)</tt>, |
| <tt>(*this)[i] == false</tt>.</li> |
| </ul> |
| |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if |
| <tt>Allocator=std::allocator</tt>).<br /> |
| |
| |
| <hr /> |
| <pre> |
| <a id="cons5">dynamic_bitset</a>(const dynamic_bitset& x) |
| </pre> |
| |
| <b>Effects:</b> Constructs a bitset that is a copy of the bitset |
| <tt>x</tt>. The allocator for this bitset is a copy of the |
| allocator in <tt>x</tt>. <br /> |
| <b>Postconditions:</b> For all <tt>i</tt> in the range |
| <tt>[0,x.size())</tt>, <tt>(*this)[i] == x[i]</tt>.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if |
| <tt>Allocator=std::allocator</tt>).<br /> |
| (Required by <a href= |
| "http://www.sgi.com/tech/stl/Assignable.html">Assignable</a>.) |
| |
| <hr /> |
| <pre> |
| template <typename BlockInputIterator> |
| explicit |
| <a id= |
| "cons4">dynamic_bitset</a>(BlockInputIterator first, BlockInputIterator last, |
| const Allocator& alloc = Allocator()); |
| </pre> |
| |
| <b>Effects:</b> |
| <ul> |
| <li> |
| If this constructor is called with a type <tt>BlockInputIterator</tt> which |
| <i>is actually an integral type</i>, the library behaves as if the constructor |
| from <tt>unsigned long</tt> were called, with arguments |
| <tt>static_cast<size_type>(first), last and alloc</tt>, in that order. |
| <br /><br /> |
| Example: |
| <pre> |
| // b is constructed as if by calling the constructor |
| // |
| // dynamic_bitset(size_type num_bits, |
| // unsigned long value = 0, |
| // const Allocator& alloc = Allocator()) |
| // |
| // with arguments |
| // |
| // static_cast<dynamic_bitset<unsigned short>::size_type>(8), |
| // 7, |
| // Allocator() |
| // |
| dynamic_bitset<unsigned short> b(8, 7); |
| </pre><br /> |
| <i>Note:</i><br/> |
| At the time of writing (October 2008) this is aligned with the |
| proposed resolution for <a href= |
| "http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#438">library |
| issue 438</a>. That is a <em>post <tt>C++03</tt></em> |
| change, and is currently in the working paper for |
| <tt>C++0x</tt>. Informally speaking, the critical changes with |
| respect to <tt>C++03</tt> are the drop of a <tt>static_cast</tt> |
| on the second argument, and more leeway as to <em>when</em> the |
| templated constructor should have the same effect as the (size, |
| value) one: only when <tt>InputIterator</tt> is an integral |
| type, in <tt>C++03</tt>; when it is either an integral type or |
| any other type that the implementation might detect as |
| impossible to be an input iterator, with the proposed |
| resolution. For the purposes of <tt>dynamic_bitset</tt> we limit |
| ourselves to the first of these two changes.<br /><br /> |
| </li> |
| <li> |
| <i>Otherwise</i> (<i>i.e.</i> if the template argument is not an |
| integral type), constructs—under the condition in the |
| <tt>requires</tt> clause—a bitset based on a range of |
| blocks. Let <tt>*first</tt> be block number 0, <tt>*++first</tt> |
| block number 1, etc. Block number <tt>b</tt> is used to |
| initialize the bits of the dynamic_bitset in the position range |
| <tt>[b*bits_per_block, (b+1)*bits_per_block)</tt>. For each |
| block number <tt>b</tt> with value <tt>bval</tt>, the bit |
| <tt>(bval >> i) & 1</tt> corresponds to the bit at |
| position <tt>(b * bits_per_block + i)</tt> in the bitset (where |
| <tt>i</tt> goes through the range <tt>[0, bits_per_block)</tt>). |
| </li> |
| </ul> |
| <br /> |
| <b>Requires:</b> <tt>BlockInputIterator</tt> must be either an |
| integral type or a model of <a href= |
| "http://www.sgi.com/tech/stl/InputIterator.html">Input |
| Iterator</a> whose <tt>value_type</tt> is the same type as |
| <tt>Block</tt>.<br /> <b>Throws:</b> An allocation error if |
| memory is exhausted (<tt>std::bad_alloc</tt> if |
| <tt>Allocator=std::allocator</tt>).<br /> |
| |
| <hr /> |
| <pre> |
| template<typename Char, typename Traits, typename Alloc> |
| explicit |
| <a id="cons3">dynamic_bitset</a>(const <a href= |
| "http://www.sgi.com/tech/stl/basic_string.html">std::basic_string</a><Char,Traits,Alloc>& s, |
| typename std::basic_string<CharT, Traits, Alloc>::size_type pos = 0, |
| typename std::basic_string<CharT, Traits, Alloc>::size_type n = <a |
| href= |
| "http://www.sgi.com/tech/stl/basic_string.html">std::basic_string</a><Char,Traits,Alloc>::npos, |
| const Allocator& alloc = Allocator()) |
| </pre> |
| |
| <b>Precondition:</b> <tt>pos <= s.size()</tt> and the |
| characters used to initialize the bits must be <tt>0</tt> or |
| <tt>1</tt>.<br /> |
| <b>Effects:</b> Constructs a bitset from a string of 0's and |
| 1's. The first <tt>M</tt> bits are initialized to the |
| corresponding characters in <tt>s</tt>, where <tt>M = |
| min(s.size() - pos, n)</tt>. Note that the <i>highest</i> |
| character position in <tt>s</tt>, not the lowest, corresponds to |
| the least significant bit. That is, character position <tt>pos + |
| M - 1 - i</tt> corresponds to bit <tt>i</tt>. So, for example, |
| <tt>dynamic_bitset(string("1101"))</tt> is the same as |
| <tt>dynamic_bitset(13ul)</tt>.<br /> |
| <b>Throws:</b> an allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if <tt>Allocator=std::allocator</tt>). |
| |
| <hr /> |
| <h3><a id="destructor">Destructor</a></h3> |
| |
| <hr /> |
| <pre> |
| ~dynamic_bitset() |
| </pre> |
| |
| <b>Effects:</b> Releases the memory associated with this bitset |
| and destroys the bitset object itself.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <h3><a id="member-functions">Member Functions</a></h3> |
| |
| <hr /> |
| <pre> |
| void <a id="swap">swap</a>(dynamic_bitset& b); |
| </pre> |
| |
| <b>Effects:</b> The contents of this bitset and bitset <tt>b</tt> |
| are exchanged.<br /> |
| <b>Postconditions:</b> This bitset is equal to the original |
| <tt>b</tt>, and <tt>b</tt> is equal to the previous version of |
| this bitset.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id= |
| "assign">operator=</a>(const dynamic_bitset& x) |
| </pre> |
| |
| <b>Effects:</b> This bitset becomes a copy of the bitset |
| <tt>x</tt>.<br /> |
| <b>Postconditions:</b> For all <tt>i</tt> in the range |
| <tt>[0,x.size())</tt>, <tt>(*this)[i] == x[i]</tt>.<br /> |
| <b>Returns:</b> <tt>*this</tt>.<br /> |
| <b>Throws:</b> nothing. <br /> |
| (Required by <a href= |
| "http://www.sgi.com/tech/stl/Assignable.html">Assignable</a>.) |
| |
| <hr /> |
| <pre> |
| allocator_type <a id="get_allocator">get_allocator()</a> const; |
| </pre> |
| <b>Returns:</b> A copy of the allocator object used to construct <tt>*this</tt>. |
| |
| <hr /> |
| <pre> |
| void <a id= |
| "resize">resize</a>(size_type num_bits, bool value = false); |
| </pre> |
| |
| <b>Effects:</b> Changes the number of bits of the bitset to |
| <tt>num_bits</tt>. If <tt>num_bits > size()</tt> then the bits |
| in the range <tt>[0,size())</tt> remain the same, and the bits in |
| <tt>[size(),num_bits)</tt> are all set to <tt>value</tt>. If |
| <tt>num_bits < size()</tt> then the bits in the range |
| <tt>[0,num_bits)</tt> stay the same (and the remaining bits are |
| discarded).<br /> |
| <b>Postconditions:</b> <tt>this->size() == num_bits</tt>.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if |
| <tt>Allocator=std::allocator</tt>).<br /> |
| |
| |
| <hr /> |
| <pre> |
| void <a id="clear">clear</a>() |
| </pre> |
| |
| <b>Effects:</b> The size of the bitset becomes zero.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| void <a id="push_back">push_back</a>(bool value); |
| </pre> |
| |
| <b>Effects:</b> Increases the size of the bitset by one, and sets |
| the value of the new most-significant bit to <tt>value</tt>.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if |
| <tt>Allocator=std::allocator</tt>).<br /> |
| |
| |
| <hr /> |
| <pre> |
| void <a id="append1">append</a>(Block value); |
| </pre> |
| |
| <b>Effects:</b> Appends the bits in <tt>value</tt> to the bitset |
| (appends to the most-significant end). This increases the size of |
| the bitset by <tt>bits_per_block</tt>. Let <tt>s</tt> be the old |
| size of the bitset, then for <tt>i</tt> in the range |
| <tt>[0,bits_per_block)</tt>, the bit at position <tt>(s + i)</tt> |
| is set to <tt>((value >> i) & 1)</tt>.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if |
| <tt>Allocator=std::allocator</tt>).<br /> |
| |
| |
| <hr /> |
| <pre> |
| template <typename BlockInputIterator> |
| void <a id= |
| "append2">append</a>(BlockInputIterator first, BlockInputIterator last); |
| </pre> |
| |
| <b>Effects:</b> This function provides the same end result as the |
| following code, but is typically more efficient. |
| |
| <pre> |
| for (; first != last; ++first) |
| append(*first); |
| </pre> |
| |
| <b>Requires:</b> The <tt>BlockInputIterator</tt> type must be a |
| model of <a href= |
| "http://www.sgi.com/tech/stl/InputIterator.html">Input |
| Iterator</a> and the <tt>value_type</tt> must be the same type as |
| <tt>Block</tt>.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if |
| <tt>Allocator=std::allocator</tt>).<br /> |
| |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id= |
| "op-and-assign">operator&=</a>(const dynamic_bitset& rhs) |
| </pre> |
| |
| <b>Requires:</b> <tt>this->size() == rhs.size()</tt>.<br /> |
| <b>Effects:</b> Bitwise-AND all the bits in <tt>rhs</tt> with |
| the bits in this bitset. This is equivalent to: |
| |
| <pre> |
| for (size_type i = 0; i != this->size(); ++i) |
| (*this)[i] = (*this)[i] & rhs[i]; |
| </pre> |
| |
| <b>Returns:</b> <tt>*this</tt>.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id= |
| "op-or-assign">operator|=</a>(const dynamic_bitset& rhs) |
| </pre> |
| |
| <b>Requires:</b> <tt>this->size() == rhs.size()</tt>.<br /> |
| <b>Effects:</b> Bitwise-OR's all the bits in <tt>rhs</tt> with |
| the bits in this bitset. This is equivalent to: |
| |
| <pre> |
| for (size_type i = 0; i != this->size(); ++i) |
| (*this)[i] = (*this)[i] | rhs[i]; |
| </pre> |
| |
| <b>Returns:</b> <tt>*this</tt>.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id= |
| "op-xor-assign">operator^=</a>(const dynamic_bitset& rhs) |
| </pre> |
| |
| <b>Requires:</b> <tt>this->size() == rhs.size()</tt>.<br /> |
| <b>Effects:</b> Bitwise-XOR's all the bits in <tt>rhs</tt> with |
| the bits in this bitset. This is equivalent to: |
| |
| <pre> |
| for (size_type i = 0; i != this->size(); ++i) |
| (*this)[i] = (*this)[i] ^ rhs[i]; |
| </pre> |
| |
| <b>Returns:</b> <tt>*this</tt>.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id= |
| "op-sub-assign">operator-=</a>(const dynamic_bitset& rhs) |
| </pre> |
| |
| <b>Requires:</b> <tt>this->size() == rhs.size()</tt>.<br /> |
| <b>Effects:</b> Computes the set difference of this bitset and |
| the <tt>rhs</tt> bitset. This is equivalent to: |
| |
| <pre> |
| for (size_type i = 0; i != this->size(); ++i) |
| (*this)[i] = (*this)[i] && !rhs[i]; |
| </pre> |
| |
| <b>Returns:</b> <tt>*this</tt>.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id= |
| "op-sl-assign">operator<<=</a>(size_type n) |
| </pre> |
| |
| <b>Effects:</b> Shifts the bits in this bitset to the left by |
| <tt>n</tt> bits. For each bit in the bitset, the bit at position |
| pos takes on the previous value of the bit at position <tt>pos - |
| n</tt>, or zero if no such bit exists.<br /> |
| <b>Returns:</b> <tt>*this</tt>.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id= |
| "op-sr-assign">operator>>=</a>(size_type n) |
| </pre> |
| |
| <b>Effects:</b> Shifts the bits in this bitset to the right by |
| <tt>n</tt> bits. For each bit in the bitset, the bit at position |
| <tt>pos</tt> takes on the previous value of bit <tt>pos + n</tt>, |
| or zero if no such bit exists.<br /> |
| <b>Returns:</b> <tt>*this</tt>.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| dynamic_bitset <a id= |
| "op-sl">operator<<</a>(size_type n) const |
| </pre> |
| |
| <b>Returns:</b> a copy of <tt>*this</tt> shifted to the left by |
| <tt>n</tt> bits. For each bit in the returned bitset, the bit at |
| position pos takes on the value of the bit at position <tt>pos - |
| n</tt> of this bitset, or zero if no such bit exists.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if <tt>Allocator=std::allocator</tt>). |
| |
| <hr /> |
| <pre> |
| dynamic_bitset <a id= |
| "op-sr">operator>></a>(size_type n) const |
| </pre> |
| |
| <b>Returns:</b> a copy of <tt>*this</tt> shifted to the right by |
| <tt>n</tt> bits. For each bit in the returned bitset, the bit at |
| position pos takes on the value of the bit at position <tt>pos + |
| n</tt> of this bitset, or zero if no such bit exists.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if <tt>Allocator=std::allocator</tt>). |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id="set1">set</a>() |
| </pre> |
| |
| <b>Effects:</b> Sets every bit in this bitset to 1.<br /> |
| <b>Returns:</b> <tt>*this</tt><br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id="flip1">flip</a>() |
| </pre> |
| |
| <b>Effects:</b> Flips the value of every bit in this bitset.<br /> |
| <b>Returns:</b> <tt>*this</tt><br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| dynamic_bitset <a id="op-not">operator~</a>() const |
| </pre> |
| |
| <b>Returns:</b> a copy of <tt>*this</tt> with all of its bits |
| flipped.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if <tt>Allocator=std::allocator</tt>). |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id="reset1">reset</a>() |
| </pre> |
| |
| <b>Effects:</b> Clears every bit in this bitset.<br /> |
| <b>Returns:</b> <tt>*this</tt><br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id= |
| "set2">set</a>(size_type n, bool val = true) |
| </pre> |
| |
| <b>Precondition:</b> <tt>n < this->size()</tt>.<br /> |
| <b>Effects:</b> Sets bit <tt>n</tt> if <tt>val</tt> is |
| <tt>true</tt>, and clears bit <tt>n</tt> if <tt>val</tt> is |
| <tt>false</tt>. <br /> |
| <b>Returns:</b> <tt>*this</tt> |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id="reset2">reset</a>(size_type n) |
| </pre> |
| |
| <b>Precondition:</b> <tt>n < this->size()</tt>.<br /> |
| <b>Effects:</b> Clears bit <tt>n</tt>.<br /> |
| <b>Returns:</b> <tt>*this</tt> |
| |
| <hr /> |
| <pre> |
| dynamic_bitset& <a id="flip2">flip</a>(size_type n) |
| </pre> |
| |
| <b>Precondition:</b> <tt>n < this->size()</tt>.<br /> |
| <b>Effects:</b> Flips bit <tt>n</tt>.<br /> |
| <b>Returns:</b> <tt>*this</tt> |
| |
| <hr /> |
| <pre> |
| size_type <a id="size">size</a>() const |
| </pre> |
| |
| <b>Returns:</b> the number of bits in this bitset.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| size_type <a id="num_blocks">num_blocks</a>() const |
| </pre> |
| |
| <b>Returns:</b> the number of blocks in this bitset.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| size_type <a id="max_size">max_size</a>() const; |
| </pre> |
| |
| <b>Returns:</b> the maximum size of a <tt>dynamic_bitset</tt> |
| object having the same type as <tt>*this</tt>. Note that if |
| any <tt>dynamic_bitset</tt> operation causes <tt>size()</tt> to |
| exceed <tt>max_size()</tt> then the <i>behavior is undefined</i>. |
| <br /><br />[The semantics of this function could change slightly |
| when lib issue 197 will be closed]<br /> |
| |
| <hr /> |
| <pre> |
| bool <a id="empty">empty</a>() const; |
| </pre> |
| |
| <b>Returns:</b> <tt>true</tt> if <tt>this->size() == 0</tt>, <tt>false</tt> |
| otherwise. <i>Note</i>: not to be confused with <tt>none()</tt>, that has |
| different semantics. |
| |
| <hr /> |
| <pre> |
| size_type <a id="count">count</a>() const |
| </pre> |
| |
| <b>Returns:</b> the number of bits in this bitset that are |
| set.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| bool <a id="any">any</a>() const |
| </pre> |
| |
| <b>Returns:</b> <tt>true</tt> if any bits in this bitset are set, |
| and otherwise returns <tt>false</tt>.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| bool <a id="none">none</a>() const |
| </pre> |
| |
| <b>Returns:</b> <tt>true</tt> if no bits are set, and otherwise |
| returns <tt>false</tt>.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| bool <a id="test">test</a>(size_type n) const |
| </pre> |
| |
| <b>Precondition:</b> <tt>n < this->size()</tt>.<br /> |
| <b>Returns:</b> <tt>true</tt> if bit <tt>n</tt> is set and |
| <tt>false</tt> is bit <tt>n</tt> is 0. |
| |
| <hr /> |
| <pre> |
| reference <a id="bracket">operator[]</a>(size_type n) |
| </pre> |
| |
| <b>Precondition:</b> <tt>n < this->size()</tt>.<br /> |
| <b>Returns:</b> a <tt>reference</tt> to bit <tt>n</tt>. Note |
| that <tt>reference</tt> is a proxy class with an assignment |
| operator and a conversion to <tt>bool</tt>, which allows you to |
| use <tt>operator[]</tt> for assignment. That is, you can write |
| both <tt>x = b[n]</tt> and <tt>b[n] = x</tt>. However, in many |
| other respects the proxy is not the same as the true reference |
| type <tt>bool&</tt>. |
| |
| <hr /> |
| <pre> |
| bool <a id="const-bracket">operator[]</a>(size_type n) const |
| </pre> |
| |
| <b>Precondition:</b> <tt>n < this->size()</tt>.<br /> |
| <b>Returns:</b> The same as <tt>test(n)</tt>. |
| |
| <hr /> |
| <pre> |
| unsigned long <a id="to_ulong">to_ulong</a>() const |
| </pre> |
| |
| <b>Returns:</b> The numeric value corresponding to the bits in <tt>*this</tt>. |
| <br /> |
| <b>Throws:</b> <tt>std::overflow_error</tt> if that value is too large to |
| be represented in an <tt>unsigned long</tt>, i.e. if <tt>*this</tt> has |
| any non-zero bit at a position <tt>>= |
| std::numeric_limits<unsigned long>::digits</tt>. |
| |
| <hr /> |
| <pre> |
| bool <a id= |
| "is_subset_of">is_subset_of</a>(const dynamic_bitset& a) const |
| </pre> |
| |
| <b>Requires:</b> <tt>this->size() == a.size()</tt><br /> |
| <b>Returns:</b> true if this bitset is a subset of bitset |
| <tt>a</tt>. That is, it returns true if, for every bit that is |
| set in this bitset, the corresponding bit in bitset <tt>a</tt> is |
| also set. Otherwise this function returns false.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| bool <a id= |
| "is_proper_subset_of">is_proper_subset_of</a>(const dynamic_bitset& a) const |
| </pre> |
| |
| <b>Requires:</b> <tt>this->size() == a.size()</tt><br /> |
| <b>Returns:</b> true if this bitset is a proper subset of bitset |
| <tt>a</tt>. That is, it returns true if, for every bit that is |
| set in this bitset, the corresponding bit in bitset <tt>a</tt> is |
| also set and if <tt>this->count() < a.count()</tt>. |
| Otherwise this function returns false.<br /> |
| <b>Throws:</b> nothing. |
| |
| <hr /> |
| <pre> |
| size_type <a id = "find_first">find_first</a>() const; |
| </pre> |
| |
| <b>Returns:</b> the lowest index <tt>i</tt> such as bit <tt>i</tt> |
| is set, or <tt>npos</tt> if <tt>*this</tt> has no on bits. |
| |
| <hr /> |
| <pre> |
| size_type <a id="find_next">find_next</a>(size_type pos) const; |
| </pre> |
| |
| <b>Returns:</b> the lowest index <tt>i</tt> greater than |
| <tt>pos</tt> such as bit <tt>i</tt> is set, or <tt>npos</tt> if |
| no such index exists. |
| |
| <hr /> |
| <pre> |
| bool <a id= |
| "op-equal">operator==</a>(const dynamic_bitset& rhs) const |
| </pre> |
| |
| <b>Returns:</b> <tt>true</tt> if <tt>this->size() == |
| rhs.size()</tt> and if for all <tt>i</tt> in the range |
| <tt>[0,rhs.size())</tt>, <tt>(*this)[i] == rhs[i]</tt>. Otherwise |
| returns <tt>false</tt>.<br /> |
| <b>Throws:</b> nothing.<br /> |
| (Required by <a href= |
| "http://www.sgi.com/tech/stl/EqualityComparable.html">Equality |
| Comparable</a>.) |
| |
| <hr /> |
| <pre> |
| bool <a id= |
| "op-not-equal">operator!=</a>(const dynamic_bitset& rhs) const |
| </pre> |
| |
| <b>Returns:</b> <tt>!((*this) == rhs)</tt><br /> |
| <b>Throws:</b> nothing.<br /> |
| (Required by <a href= |
| "http://www.sgi.com/tech/stl/EqualityComparable.html">Equality |
| Comparable</a>.) |
| |
| <hr /> |
| <pre> |
| bool <a id= |
| "op-less">operator<</a>(const dynamic_bitset& rhs) const |
| </pre> |
| |
| <b>Returns:</b> <tt>true</tt> if this bitset is lexicographically |
| less than <tt>rhs</tt>, and returns <tt>false</tt> otherwise. |
| (See the description of <a href= |
| "http://www.sgi.com/tech/stl/lexicographical_compare.html">lexicographical_compare</a> |
| for a definition of lexicographic ordering). <br /> |
| <b>Throws:</b> nothing.<br /> |
| (Required by <a href= |
| "http://www.sgi.com/tech/stl/LessThanComparable.html">Less Than |
| Comparable</a>.) |
| |
| <hr /> |
| <pre> |
| bool <a id= |
| "op-greater">operator></a>(const dynamic_bitset& rhs) const |
| </pre> |
| |
| <b>Returns:</b> <tt>!((*this) < rhs || (*this) == |
| rhs)</tt><br /> |
| <b>Throws:</b> nothing.<br /> |
| (Required by <a href= |
| "http://www.sgi.com/tech/stl/LessThanComparable.html">Less Than |
| Comparable</a>.) |
| |
| <hr /> |
| <pre> |
| bool <a id= |
| "op-less-equal">operator<=</a>(const dynamic_bitset& rhs) const |
| </pre> |
| |
| <b>Returns:</b> <tt>(*this) < rhs || (*this) == rhs</tt><br /> |
| <b>Throws:</b> nothing.<br /> |
| (Required by <a href= |
| "http://www.sgi.com/tech/stl/LessThanComparable.html">Less Than |
| Comparable</a>.) |
| |
| <hr /> |
| <pre> |
| bool <a id= |
| "op-greater-equal">operator>=</a>(const dynamic_bitset& rhs) const |
| </pre> |
| |
| <b>Returns:</b> <tt>(*this) > rhs || (*this) == rhs</tt><br /> |
| <b>Throws:</b> nothing.<br /> |
| (Required by <a href= |
| "http://www.sgi.com/tech/stl/LessThanComparable.html">Less Than |
| Comparable</a>.) |
| |
| <hr /> |
| <h3><a id="non-member-functions">Non-Member Functions</a></h3> |
| |
| <hr /> |
| <pre> |
| dynamic_bitset <a id= |
| "op-and">operator&</a>(const dynamic_bitset& a, const dynamic_bitset& b) |
| </pre> |
| |
| <b>Requires:</b> <tt>a.size() == b.size()</tt><br /> |
| <b>Returns:</b> A new bitset that is the bitwise-AND of the |
| bitsets <tt>a</tt> and <tt>b</tt>.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if <tt>Allocator=std::allocator</tt>). |
| |
| <hr /> |
| <pre> |
| dynamic_bitset <a id= |
| "op-or">operator|</a>(const dynamic_bitset& a, const dynamic_bitset& b) |
| </pre> |
| |
| <b>Requires:</b> <tt>a.size() == b.size()</tt><br /> |
| <b>Returns:</b> A new bitset that is the bitwise-OR of the |
| bitsets <tt>a</tt> and <tt>b</tt>.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if <tt>Allocator=std::allocator</tt>). |
| |
| <hr /> |
| <pre> |
| dynamic_bitset <a id= |
| "op-xor">operator^</a>(const dynamic_bitset& a, const dynamic_bitset& b) |
| </pre> |
| |
| <b>Requires:</b> <tt>a.size() == b.size()</tt><br /> |
| <b>Returns:</b> A new bitset that is the bitwise-XOR of the |
| bitsets <tt>a</tt> and <tt>b</tt>.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if <tt>Allocator=std::allocator</tt>). |
| |
| <hr /> |
| <pre> |
| dynamic_bitset <a id= |
| "op-sub">operator-</a>(const dynamic_bitset& a, const dynamic_bitset& b) |
| </pre> |
| |
| <b>Requires:</b> <tt>a.size() == b.size()</tt><br /> |
| <b>Returns:</b> A new bitset that is the set difference of the |
| bitsets <tt>a</tt> and <tt>b</tt>.<br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if <tt>Allocator=std::allocator</tt>). |
| |
| <hr /> |
| <pre> |
| template <typename CharT, typename Alloc> |
| void <a id= |
| "to_string">to_string</a>(const dynamic_bitset<Block, Allocator>& b, |
| <a href= |
| "http://www.sgi.com/tech/stl/basic_string.html">std::basic_string</a><Char,Traits,Alloc>& s) |
| </pre> |
| |
| <b>Effects:</b> Copies a representation of <tt>b</tt> into the |
| string <tt>s</tt>. A character in the string is <tt>'1'</tt> if |
| the corresponding bit is set, and <tt>'0'</tt> if it is not. |
| Character position <tt>i</tt> in the string corresponds to bit |
| position <tt>b.size() - 1 - i</tt>. <br /> |
| <b>Throws:</b> If memory is exhausted, the string will throw an |
| allocation error.<br /> |
| <b>Rationale:</b> This function is not a member function taking |
| zero arguments and returning a string for a couple reasons. |
| First, this version can be slighly more efficient because the |
| string is not copied (due to being passed by value). Second, as a |
| member function, to allow for flexibility with regards to the |
| template parameters of <tt>basic_string</tt>, the member function |
| would require explicit template parameters. Few C++ programmers |
| are familiar with explicit template parameters, and some C++ |
| compilers do not handle them properly. |
| |
| <hr /> |
| <pre> |
| template <typename Block, typename Alloc, typename BlockOutputIterator> |
| void <a id= |
| "to_block_range">to_block_range</a>(const dynamic_bitset<Block, Alloc>& b, BlockOutputIterator result) |
| </pre> |
| |
| <b>Effects:</b> Writes the bits of the bitset into the iterator |
| <tt>result</tt> a block at a time. The first block written |
| represents the bits in the position range |
| <tt>[0,bits_per_block)</tt> in the bitset, the second block |
| written the bits in the range |
| <tt>[bits_pre_block,2*bits_per_block)</tt>, and so on. For each |
| block <tt>bval</tt> written, the bit <tt>(bval >> i) & |
| 1</tt> corresponds to the bit at position <tt>(b * bits_per_block |
| + i)</tt> in the bitset.<br /> |
| <b>Requires:</b> The type <tt>BlockOutputIterator</tt> must be a |
| model of <a href= |
| "http://www.sgi.com/tech/stl/OutputIterator.html">Output |
| Iterator</a> and its <tt>value_type</tt> must be the same type as |
| <tt>Block</tt>. Further, the size of the output range must be |
| greater or equal <tt>b.num_blocks()</tt>. |
| |
| <hr /> |
| <pre> |
| template <typename BlockIterator, typename Block, typename Alloc> |
| void <a id= |
| "from_block_range">from_block_range</a>(BlockIterator first, |
| BlockIterator last, const dynamic_bitset<Block, Alloc>& b) |
| </pre> |
| |
| <b>Effects:</b> Reads blocks from the iterator range into the |
| bitset. <br /> |
| <b>Requires:</b> The type <tt>BlockIterator</tt> must be a model |
| of <a href="http://www.sgi.com/tech/stl/InputIterator.html">Input |
| Iterator</a> and its <tt>value_type</tt> must be the same type as |
| <tt>Block</tt>. The size of the iterator range must be less or |
| equal to <tt>b.num_blocks()</tt>. |
| |
| <hr /> |
| <pre> |
| template <typename Char, typename Traits, typename Block, typename Alloc> |
| basic_ostream<Char, Traits>& |
| <a id= |
| "op-out">operator<<</a>(basic_ostream<Char, Traits>& os, const dynamic_bitset<Block, Alloc>& b) |
| </pre> |
| |
| <b>Effects:</b> Inserts a textual representation of b into the stream |
| <tt>os</tt> (highest bit first). Informally, the output is the same as doing |
| |
| <pre> |
| std::basic_string<Char, Traits> s; |
| boost::to_string(x, s): |
| os << s; |
| </pre> |
| |
| except that the stream inserter takes into accout the locale imbued into |
| <tt>os</tt>, which <tt>boost::to_string()</tt> can't do. Here is a more |
| precise specification, given in terms of "as if" rule: first, for each |
| valid position i into the bitset <tt>b</tt> let's put: |
| |
| <tt>character_of(b[i)]) = b[i]? os.widen('1') : os.widen('0');</tt> |
| |
| Let also <tt>s</tt> be a <tt>std::basic_string<Char, Traits></tt> |
| object, having length <tt>b.size()</tt> and such as, for each <tt>i</tt> |
| in <tt>[0, b.size())</tt>, |
| |
| <tt>s[i] is character_of(b[i])</tt> |
| |
| Then, the output, the effects on <tt>os</tt> and the exception behavior |
| is the same as outputting the object <tt>s</tt> to <tt>os</tt> (same |
| width, same exception mask, same padding, same setstate() logic) |
| <br /> |
| <b>Returns:</b> os <br /> |
| <b>Throws:</b> <tt>std::ios_base::failure</tt> if there is a |
| problem writing to the stream. |
| |
| <hr /> |
| <pre> |
| template <typename Char, typename Traits, typename Block, typename Alloc> |
| std::basic_istream<Char,Traits>& |
| <a id= |
| "op-in">operator>></a>(std::basic_istream<Char,Traits>& is, dynamic_bitset<Block, Alloc>& b) |
| </pre> |
| |
| <b>Effects:</b> Extracts a <tt>dynamic_bitset</tt> from an input stream. |
| <br /><br /> |
| <i>Definitions:</i><br /><br /> |
| Let <i>Tr</i> be the traits_type of <i>is</i>. Then: |
| <ol> |
| <li> |
| A (non-eof) character <tt>c</tt> extracted from <tt>is</tt> |
| is a <i>bitset digit</i> if and only if either Tr::eq(c, is.widen('0')) or |
| Tr::eq(c, is.widen('1')) return true. |
| </li> |
| <li>If c is a bitset digit, it's <i>corresponding bit value</i> is 0 if |
| Tr::eq(c, is.widen('0')) is true, 1 otherwise. |
| </li> |
| </ol> |
| |
| The function begins by constructing a <tt>sentry</tt> object <tt>k</tt> as if <tt>k</tt> |
| were constructed by |
| |
| <tt>typename std::basic_istream<Char, Traits>::sentry k(is)</tt>. |
| |
| If <tt>bool(k)</tt> is true, it calls <tt>b.clear()</tt> |
| then attempts to extract characters from <tt>is</tt>. For each character c |
| that is a <i>bitset digit</i> the <i>corresponding bit value</i> is |
| appended to the less significant end of <tt>b</tt> (appending may throw). |
| If <tt>is.width()</tt> is greater than zero and smaller than <tt>b.max_size()</tt> |
| then the maximum number <tt>n</tt> of bits appended is <tt>is.width()</tt>; |
| otherwise <tt>n</tt> = <tt>b.max_size()</tt>. |
| |
| Unless the extractor is exited via an exception, characters are extracted (and |
| corresponding bits appended) until any of the following occurs:<br /> |
| |
| <ul> |
| <li> <tt>n</tt> bits are stored into the bitset;</li> |
| <li> end-of-file, or an error, occurs on the input sequence;</li> |
| <li> the next available input character isn't a bitset digit</li> |
| </ul> |
| <br /> If no exception caused the function to exit then <tt>is.width(0)</tt> is |
| called, regardless of how many characters were actually extracted. The |
| sentry object k is destroyed. |
| <br /> |
| <br />If the function extracts no characters[???], it calls is.setstate(std::ios::failbit), |
| which may throw <tt>std::ios_base::failure</tt>. |
| |
| |
| <br />------ |
| |
| |
| <br /> |
| <b>Throws:</b> An allocation error if memory is exhausted |
| (<tt>std::bad_alloc</tt> if <tt>Allocator=std::allocator</tt>). |
| A <tt>std::ios_base::failure</tt> if there is a problem reading |
| from the stream. |
| |
| <hr /> |
| <h3><a id="exception-guarantees">Exception guarantees</a></h3> |
| |
| All of <tt>dynamic_bitset</tt> functions offer at least the basic |
| exception guarantee. |
| |
| <hr /> |
| <h3><a id="changes-from-previous-ver">Changes from previous version(s)</a></h3> |
| |
| <h4><i>Changes in Boost 1.37.0</i></h4> |
| <ul> |
| <li>The constructor from a block range implements a "do the right thing" |
| behavior, a la standard sequences.</li> |
| </ul> |
| |
| <!-- Changes from Boost 1.31.0 --> |
| <h4><i>Changes from Boost 1.31.0</i></h4> |
| <ul> |
| <li> |
| The stream extractor has completely different semantics: as natural |
| for a dynamic structure, it now expands the bitset as needed during |
| extraction. The new behaviour mimics that of the <tt>basic_string</tt> |
| extractor but there are some differences the user should be aware of; |
| so, please, check the <a href="#op-in">documentation</a>. (One |
| difference concerns the case where <code>stream.width() > |
| bitset.max_size() > 0</code>. In that circumstance the |
| extractor of <tt>dynamic_bitset</tt> never attempts to extract more |
| than <tt>max_size()</tt> characters, whereas the extractor of |
| <tt>basic_string</tt> goes on and, on conforming implementations, |
| eventually throws a <tt>length_error</tt> exception. Note: That's what |
| the standard mandates -see especially <a |
| href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#83">library |
| issue 83</a>- but not all implementations conform) |
| <br /><br /> |
| The stream extractor is now also "exception-aware" in the sense that |
| it works correctly when setting exception masks on the stream. |
| <br /><br /> |
| </li> |
| <li> |
| Several member functions (<tt>empty()</tt>, <tt>find_first()</tt> |
| , <tt>find_next()</tt>, <tt>get_allocator()</tt>, <tt>intersects()</tt> |
| , <tt>max_size()</tt> <!--, <tt>reserve()</tt>, <tt>capacity()</tt> -->) |
| have been added. |
| </li> |
| <li> |
| The constructor from <tt>basic_string</tt> has a new parameter that was totally |
| forgotten before. |
| </li> |
| |
| </ul> |
| <i>Technicalities and minor changes</i> |
| <ul> |
| <li> |
| The class <tt>reference</tt> has been reimplemented so that |
| dynamic_bitset's references behave more like references to standard |
| container elements. In particular it is now guaranteed that they |
| cannot be invalidated from a standard library swap() function |
| applied to their corresponding <tt>dynamic_bitset</tt>s. |
| </li> |
| </ul> |
| <i>General improvements</i> |
| <br /><br /> |
| Several optimizations to member and non-member functions and to the |
| nested class <tt>reference</tt>. |
| |
| <hr /> |
| <h3><a id="see-also">See also</a></h3> |
| |
| <tt><a href= |
| "http://www.sgi.com/tech/stl/bitset.html">std::bitset</a></tt>, |
| <tt><a href= |
| "http://www.sgi.com/tech/stl/Vector.html">std::vector</a></tt>, |
| |
| <h3><a id="acknowledgements">Acknowledgements</a></h3> |
| |
| <p>We would like to thank the Boost community for putting in the |
| time to review and accept this library. This library is much |
| better than it ever would have been due to all the suggestions |
| from Boost members. We especially thank Matt Marcus for taking on |
| the task of review manager. Also, a special thanks goes to |
| James Kanze for his invaluable help with the internationalization |
| issues.</p> |
| |
| <table summary="Copyright"> <tr> <td>Copyright © 2001</td> |
| <td><a href="http://www.boost.org/people/jeremy_siek.htm">Jeremy |
| Siek</a>, Indiana University (<a |
| href="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</a>)<br /> <a |
| href="http://freshsources.com">Chuck Allison</a>, Senior Editor, |
| C/C++ Users Journal (<a |
| href="mailto:cda@freshsources.com">cda@freshsources.com</a>)<br |
| /></td> </tr> <tr> |
| <td>Copyright © 2003-2004, 2008</td> <td><a |
| href="http://gennaro-prota.50webs.com/">Gennaro Prota</a> |
| (name.surname yahoo.com)</td> |
| </tr> |
| </table> |
| <br /> |
| <div class="legalnotice"> |
| Distributed under the Boost Software License, Version 1.0. |
| (See accompanying file <a href="../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> |
| or copy at <a class="ulink" href="http://www.boost.org/LICENSE_1_0.txt"> |
| http://www.boost.org/LICENSE_1_0.txt</a>) |
| </div> |
| |
| |
| </div> |
| </div> |
| </div> |
| </div> |
| </div> |
| </div> |
| </body> |
| <!-- LocalWords: dynamic bitset alt gif iostream hpp int bitsets const ul ulong --> |
| <!-- LocalWords: STL LessThan alloc num typename BlockInputIterator html pos --> |
| <!-- LocalWords: npos bool rhs OR's XOR's val CharT istream ostream os siek --> |
| <!-- LocalWords: htm namespace enum sizeof BlockOutputIterator fwd ith jth --> |
| </html> |