ceph/src/boost/libs/test/doc/snippet/const_string.hpp

   1 //  (C) Copyright Gennadiy Rozental 2001-2014.
   2 //  Distributed under the Boost Software License, Version 1.0.
   3 //  (See accompanying file LICENSE_1_0.txt or copy at
   4 //  http://www.boost.org/LICENSE_1_0.txt)
   5 //
   6 //  See http://www.boost.org/libs/test for the library home page.
   7 //
   8 //  Description : simple string class definition
   9 // ***************************************************************************
  10
  11 #ifndef  CONST_STRING_HPP
  12 #define  CONST_STRING_HPP
  13
  14 // STL
  15 #include <string>
  16 using std::string;
  17
  18 namespace common_layer
  19 {
  20
  21   // ************************************************************************** //
  22   // **************                 const_string                 ************** //
  23   // ************************************************************************** //
  24
  25   class const_string
  26   {
  27   public:
  28     // Subtypes
  29     typedef char const*                                 iterator;
  30     typedef char const*                                 const_iterator;
  31     typedef std::reverse_iterator<iterator,char, char const&> reverse_iterator;
  32     typedef reverse_iterator                            const_reverse_iterator;
  33
  34     // Constructor
  35     const_string() :
  36       m_begin( "" ),
  37       m_end( m_begin )
  38     {}
  39
  40     // Copy constructor is generated by compiler
  41
  42     const_string( const std::string& s ) :
  43       m_begin( s.c_str() ),
  44       m_end( m_begin + s.length() )
  45     {}
  46
  47     const_string( char const* s );
  48
  49     const_string( char const* s, size_t length ) :
  50       m_begin( s ),
  51       m_end( m_begin + length )
  52     {
  53       if(length == 0)
  54         erase();
  55     }
  56
  57     const_string( char const* first, char const* last ) :
  58       m_begin( first ),
  59       m_end( last )
  60     {}
  61
  62     // data access methods
  63     char operator[]( size_t index ) const { return m_begin[index]; }
  64     char at( size_t index ) const         { return (*this)[index]; }
  65     char const* data() const              { return m_begin;}
  66
  67     // length operators
  68     size_t length() const                 { return m_end - m_begin;}
  69     bool is_empty() const                 { return m_end == m_begin;}
  70
  71     void erase()                          { m_begin = m_end = ""; }
  72     void resize( size_t new_len )         { if( m_begin + new_len < m_end ) m_end = m_begin + new_len; }
  73     void rshorten( size_t shift = 1 )     { m_end  -= shift; if( m_end <= m_begin ) erase(); }
  74     void lshorten( size_t shift = 1 )     { m_begin += shift; if( m_end <= m_begin ) erase(); }
  75
  76     // Assignment operators
  77     const_string& operator=( const_string const& s );
  78     const_string& operator=( string const& s )            { return *this = const_string( s ); }
  79     const_string& operator=( char const* s )              { return *this = const_string( s ); }
  80
  81     const_string& assign( const_string const& s )         { return *this = s; }
  82     const_string& assign( string const& s, size_t len )   { return *this = const_string( s.data(), len ); }
  83     const_string& assign( string const& s )               { return *this = const_string( s ); }
  84     const_string& assign( char const* s )                 { return *this = const_string( s ); }
  85     const_string& assign( char const* s, size_t len )     { return *this = const_string( s, len ); }
  86     const_string& assign( char const* f, char const* l )  { return *this = const_string( f, l ); }
  87
  88     void swap( const_string& s )
  89     {
  90       // do not want to include alogrithm
  91       char const* tmp1 = m_begin;
  92       char const* tmp2 = m_end;
  93
  94       m_begin     = s.m_begin;
  95       m_end       = s.m_end;
  96
  97       s.m_begin   = tmp1;
  98       s.m_end     = tmp2;
  99     }
 100
 101     // Comparison operators
 102     friend bool     operator==( const_string const& s1, const_string const& s2 );
 103     friend bool     operator==( const_string const& s1, char const* s2 )            { return s1 == const_string( s2 ); }
 104     friend bool     operator==( const_string const& s1, const string& s2 )          { return s1 == const_string( s2 ); }
 105
 106     friend bool     operator!=( const_string const& s1, const_string const& s2 )    { return !(s1 == s2); }
 107     friend bool     operator!=( const_string const& s1, char const* s2 )            { return !(s1 == s2); }
 108     friend bool     operator!=( const_string const& s1, const string& s2 )          { return !(s1 == s2); }
 109
 110     friend bool     operator==( char const* s2,         const_string const& s1 )    { return s1 == s2; }
 111     friend bool     operator==( const string& s2,       const_string const& s1 )    { return s1 == s2; }
 112
 113     friend bool     operator!=( char const* s2,         const_string const& s1 )    { return !(s1 == s2); }
 114     friend bool     operator!=( const string& s2,       const_string const& s1 )    { return !(s1 == s2); }
 115
 116     // Iterators
 117     iterator        begin() const                           { return m_begin; }
 118     iterator        end() const                             { return m_end;   }
 119     reverse_iterator rbegin() const                         { return m_end;   }
 120     reverse_iterator rend() const                           { return m_begin; }
 121
 122     // search operation
 123     iterator        find_first_of( char c );
 124     iterator        find_first_of( const_string cs );
 125     iterator        find_last_of( char c );
 126     iterator        find_last_of( const_string cs );
 127
 128   private:
 129
 130     // Data members
 131     char const*     m_begin;
 132     char const*     m_end;
 133   };
 134
 135   //____________________________________________________________________________//
 136
 137   // first character
 138   class first_char {
 139   public:
 140     char operator()( const_string source, char default_char = '\0' ) const {
 141       return source.is_empty() ? default_char : *source.data();
 142     }
 143   };
 144
 145   //____________________________________________________________________________//
 146
 147   // last character
 148   class last_char {
 149   public:
 150     char operator()( const_string source, char default_char = '\0' ) const {
 151       return source.is_empty() ? default_char : *source.rbegin();
 152     }
 153   };
 154
 155   //____________________________________________________________________________//
 156
 157   inline const_string&
 158   const_string::operator=( const_string const& s ) {
 159     if( &s != this ) {
 160       m_begin = s.m_begin;
 161       m_end  = s.m_end;
 162     }
 163
 164     return *this;
 165   }
 166
 167   //____________________________________________________________________________//
 168
 169   typedef const_string const literal;
 170
 171 }; // namespace common_layer
 172
 173 #endif // CONST_STRING_HPP