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 // File : $RCSfile$
9 //
10 // Version : $Revision$
11 //
12 // Description : simple string class definition
13 // ***************************************************************************
14
15 #ifndef CONST_STRING_HPP
16 #define CONST_STRING_HPP
17
18 // STL
19 #include <iterator>
20 #include <string>
21 #include <cstring>
22 using std::string;
23
24 namespace common_layer {
25
26 // ************************************************************************** //
27 // ************** const_string ************** //
28 // ************************************************************************** //
29
30 class const_string {
31 public:
32 // Subtypes
33 typedef char const* iterator;
34 typedef char const* const_iterator;
35 typedef std::reverse_iterator<iterator> reverse_iterator;
36 typedef reverse_iterator const_reverse_iterator;
37
38 // Constructor
const_string()39 const_string()
40 : m_begin( "" ), m_end( m_begin ) {}
41
42 // Copy constructor is generated by compiler
43
const_string(const std::string & s)44 const_string( const std::string& s )
45 : m_begin( s.c_str() ),
46 m_end( m_begin + s.length() ) {}
47
const_string(char const * s)48 const_string( char const* s )
49 : m_begin( s ? s : "" )
50 , m_end( s ? m_begin + std::strlen( s ) : m_begin )
51 {}
52
const_string(char const * s,size_t length)53 const_string( char const* s, size_t length )
54 : m_begin( s ), m_end( m_begin + length ) { if( length == 0 ) erase(); }
55
const_string(char const * first,char const * last)56 const_string( char const* first, char const* last )
57 : m_begin( first ), m_end( last ) {}
58
59 // data access methods
operator [](size_t index) const60 char operator[]( size_t index ) const { return m_begin[index]; }
at(size_t index) const61 char at( size_t index ) const { return m_begin[index]; }
62
data() const63 char const* data() const { return m_begin; }
64
65 // length operators
length() const66 size_t length() const { return m_end - m_begin; }
is_empty() const67 bool is_empty() const { return m_end == m_begin; }
68
erase()69 void erase() { m_begin = m_end = ""; }
resize(size_t new_len)70 void resize( size_t new_len ) { if( m_begin + new_len < m_end ) m_end = m_begin + new_len; }
rshorten(size_t shift=1)71 void rshorten( size_t shift = 1 ) { m_end -= shift; if( m_end <= m_begin ) erase(); }
lshorten(size_t shift=1)72 void lshorten( size_t shift = 1 ) { m_begin += shift; if( m_end <= m_begin ) erase(); }
73
74 // Assignment operators
75 const_string& operator=( const_string const& s );
operator =(string const & s)76 const_string& operator=( string const& s ) { return *this = const_string( s ); }
operator =(char const * s)77 const_string& operator=( char const* s ) { return *this = const_string( s ); }
78
assign(const_string const & s)79 const_string& assign( const_string const& s ) { return *this = s; }
assign(string const & s,size_t len)80 const_string& assign( string const& s, size_t len ) { return *this = const_string( s.data(), len ); }
assign(string const & s)81 const_string& assign( string const& s ) { return *this = const_string( s ); }
assign(char const * s)82 const_string& assign( char const* s ) { return *this = const_string( s ); }
assign(char const * s,size_t len)83 const_string& assign( char const* s, size_t len ) { return *this = const_string( s, len ); }
assign(char const * f,char const * l)84 const_string& assign( char const* f, char const* l ) { return *this = const_string( f, l ); }
85
swap(const_string & s)86 void swap( const_string& s ) {
87 // do not want to include alogrithm
88 char const* tmp1 = m_begin;
89 char const* tmp2 = m_end;
90
91 m_begin = s.m_begin;
92 m_end = s.m_end;
93
94 s.m_begin = tmp1;
95 s.m_end = tmp2;
96 }
97
98 // Comparison operators
operator ==(const_string const & s1,const_string const & s2)99 friend bool operator==( const_string const& s1, const_string const& s2 )
100 {
101 return s1.length() == s2.length() && std::strncmp( s1.data(), s2.data(), s1.length() ) == 0;
102 }
operator ==(const_string const & s1,char const * s2)103 friend bool operator==( const_string const& s1, char const* s2 ) { return s1 == const_string( s2 ); }
operator ==(const_string const & s1,const string & s2)104 friend bool operator==( const_string const& s1, const string& s2 ) { return s1 == const_string( s2 ); }
105
operator !=(const_string const & s1,const_string const & s2)106 friend bool operator!=( const_string const& s1, const_string const& s2 ) { return !(s1 == s2); }
operator !=(const_string const & s1,char const * s2)107 friend bool operator!=( const_string const& s1, char const* s2 ) { return !(s1 == s2); }
operator !=(const_string const & s1,const string & s2)108 friend bool operator!=( const_string const& s1, const string& s2 ) { return !(s1 == s2); }
109
operator ==(char const * s2,const_string const & s1)110 friend bool operator==( char const* s2, const_string const& s1 ) { return s1 == s2; }
operator ==(const string & s2,const_string const & s1)111 friend bool operator==( const string& s2, const_string const& s1 ) { return s1 == s2; }
112
operator !=(char const * s2,const_string const & s1)113 friend bool operator!=( char const* s2, const_string const& s1 ) { return !(s1 == s2); }
operator !=(const string & s2,const_string const & s1)114 friend bool operator!=( const string& s2, const_string const& s1 ) { return !(s1 == s2); }
115
116 // Iterators
begin() const117 iterator begin() const { return m_begin; }
end() const118 iterator end() const { return m_end; }
rbegin() const119 reverse_iterator rbegin() const { return reverse_iterator( m_end ); }
rend() const120 reverse_iterator rend() const { return reverse_iterator( m_begin ); }
121
122 private:
123
124 // Data members
125 char const* m_begin;
126 char const* m_end;
127 };
128
129 //____________________________________________________________________________//
130
131 // first character
132 class first_char {
133 public:
operator ()(const_string source,char default_char='\\0') const134 char operator()( const_string source, char default_char = '\0' ) const {
135 return source.is_empty() ? default_char : *source.data();
136 }
137 };
138
139 //____________________________________________________________________________//
140
141 // last character
142 class last_char {
143 public:
operator ()(const_string source,char default_char='\\0') const144 char operator()( const_string source, char default_char = '\0' ) const {
145 return source.is_empty() ? default_char : *source.rbegin();
146 }
147 };
148
149 //____________________________________________________________________________//
150
151 inline const_string&
operator =(const_string const & s)152 const_string::operator=( const_string const& s ) {
153 if( &s != this ) {
154 m_begin = s.m_begin;
155 m_end = s.m_end;
156 }
157
158 return *this;
159 }
160
161 //____________________________________________________________________________//
162
163 typedef const_string const literal;
164
165 //____________________________________________________________________________//
166
167 inline std::ostream&
operator <<(std::ostream & os,const_string const & str)168 operator<<( std::ostream& os, const_string const& str )
169 {
170 os << std::string( str.begin(), str.length() );
171
172 return os;
173 }
174
175 //____________________________________________________________________________//
176
177 }; // namespace common_layer
178
179 #endif // CONST_STRING_HPP
180