1 /* Copyright (c) 2015-2017. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #ifndef SIMGRID_XBT_STRING_HPP
7 #define SIMGRID_XBT_STRING_HPP
9 #include <simgrid_config.h>
22 #include <xbt/sysdep.h>
31 /** POD structure representation of a string
38 /** A std::string-like with well-known representation
40 * HACK, this is a (incomplete) replacement for `std::string`.
41 * It has a fixed POD representation (`simgrid::xbt::string_data`)
42 * which can be used to easily read the string content from another
45 * The internal representation of a `std::string` is private.
46 * We could add some code to read this for a given implementation.
47 * However, even if we focus on GNU libstdc++ with Itanium ABI
48 * GNU libstdc++ currently has two different ABIs
50 * * the pre-C++11 is a pointer to a ref-counted
51 * string-representation (with support for COW);
53 * * the [C++11-conforming implementation](https://gcc.gnu.org/gcc-5/changes.html)
54 * does not use refcouting/COW but has a small string optimization.
56 XBT_PUBLIC_CLASS string : private string_data {
57 static const char NUL;
61 typedef std::size_t size_type;
62 typedef std::ptrdiff_t difference_type;
63 typedef char& reference;
64 typedef const char& const_reference;
65 typedef char* pointer;
66 typedef const char* const_pointer;
67 typedef char* iterator;
68 typedef const char* const_iterator;
73 if (string_data::data != &NUL)
74 std::free(string_data::data);
78 string(const char* s, size_t size)
82 string_data::data = const_cast<char*>(&NUL);
84 string_data::len = size;
85 string_data::data = static_cast<char*>(std::malloc(string_data::len + 1));
86 memcpy(string_data::data, s, string_data::len);
87 string_data::data[string_data::len] = '\0';
90 string() : string (const_cast<char*>(&NUL), 0) {}
91 string(const char* s) : string(s, strlen(s)) {}
92 string(string const& s) : string(s.c_str(), s.size()) {}
95 string_data::len = s.string_data::len;
96 string_data::data = s.string_data::data;
97 s.string_data::len = 0;
98 s.string_data::data = const_cast<char*>(&NUL);
100 string(std::string const& s) : string(s.c_str(), s.size()) {}
103 void assign(const char* s, size_t size)
105 if (string_data::data != &NUL) {
106 std::free(string_data::data);
107 string_data::data = nullptr;
108 string_data::len = 0;
111 string_data::len = size;
112 string_data::data = (char*) std::malloc(string_data::len + 1);
113 std::memcpy(string_data::data, s, string_data::len);
114 string_data::data[string_data::len] = '\0';
119 string& operator=(const char* s)
121 assign(s, std::strlen(s));
124 string& operator=(string const& s)
126 assign(s.c_str(), s.size());
129 string& operator=(std::string const& s)
131 assign(s.c_str(), s.size());
136 size_t size() const { return len; }
137 size_t length() const { return len; }
138 bool empty() const { return len != 0; }
139 void shrink_to_fit() {}
142 char* data() { return string_data::data; }
143 const char* data() const { return string_data::data; }
144 char* c_str() { return string_data::data; }
145 const char* c_str() const { return string_data::data; };
146 reference at(size_type i)
149 throw std::out_of_range("Out of range");
152 const_reference at(size_type i) const
155 throw std::out_of_range("Out of range");
158 reference operator[](size_type i)
162 const_reference operator[](size_type i) const
167 operator std::string() const { return std::string(this->c_str(), this->size()); }
170 iterator begin() { return data(); }
171 iterator end() { return data() + size(); }
172 const_iterator begin() const { return data(); }
173 const_iterator end() const { return data() + size(); }
174 const_iterator cbegin() const { return data(); }
175 const_iterator cend() const { return data() + size(); }
176 // (Missing, reverse iterators)
181 string_data::len = 0;
182 string_data::data = const_cast<char*>(&NUL);
185 bool equals(const char* data, std::size_t len) const
187 return this->size() == len
188 && std::memcmp(this->c_str(), data, len) == 0;
191 bool operator==(string const& that) const
193 return this->equals(that.c_str(), that.size());
195 bool operator==(std::string const& that) const
197 return this->equals(that.c_str(), that.size());
199 bool operator==(const char* that) const
201 return this->equals(that, std::strlen(that));
205 bool operator!=(X const& that) const
207 return not (*this == that);
211 int compare(const char* data, std::size_t len) const
213 size_t n = std::min(this->size(), len);
214 int res = memcmp(this->c_str(), data, n);
217 else if (this->size() == len)
219 else if (this->size() < len)
224 int compare(string const& that) const
226 return this->compare(that.c_str(), that.size());
228 int compare(std::string const& that) const
230 return this->compare(that.c_str(), that.size());
232 int compare(const char* that) const
234 return this->compare(that, std::strlen(that));
237 // Define < <= >= > in term of compare():
239 bool operator<(X const& that) const
241 return this->compare(that) < 0;
244 bool operator<=(X const& that) const
246 return this->compare(that) <= 0;
249 bool operator>(X const& that) const
251 return this->compare(that) > 0;
254 bool operator>=(X const& that) const
256 return this->compare(that) >= 0;
261 bool operator==(std::string const& a, string const& b)
266 bool operator!=(std::string const& a, string const& b)
271 bool operator<(std::string const& a, string const& b)
276 bool operator<=(std::string const& a, string const& b)
281 bool operator>(std::string const& a, string const& b)
286 bool operator>=(std::string const& a, string const& b)
293 typedef std::string string;
297 /** Create a C++ string from a C-style format
301 std::string string_printf(const char *fmt, ...);
303 /** Create a C++ string from a C-style format
307 std::string string_vprintf(const char *fmt, va_list ap);