1 /* Copyright (c) 2015-2018. 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>
23 #include <xbt/sysdep.h>
32 /** POD structure representation of a string
39 /** A std::string-like with well-known representation
41 * HACK, this is a (incomplete) replacement for `std::string`.
42 * It has a fixed POD representation (`simgrid::xbt::string_data`)
43 * which can be used to easily read the string content from another
46 * The internal representation of a `std::string` is private.
47 * We could add some code to read this for a given implementation.
48 * However, even if we focus on GNU libstdc++ with Itanium ABI
49 * GNU libstdc++ currently has two different ABIs
51 * * the pre-C++11 is a pointer to a ref-counted
52 * string-representation (with support for COW);
54 * * the [C++11-conforming implementation](https://gcc.gnu.org/gcc-5/changes.html)
55 * does not use refcouting/COW but has a small string optimization.
57 class XBT_PUBLIC string : private string_data {
62 typedef std::size_t size_type;
63 typedef std::ptrdiff_t difference_type;
64 typedef char& reference;
65 typedef const char& const_reference;
66 typedef char* pointer;
67 typedef const char* const_pointer;
68 typedef char* iterator;
69 typedef const char* const_iterator;
74 if (string_data::data != &NUL)
75 delete[] string_data::data;
79 string(const char* s, size_t size)
83 string_data::data = &NUL;
85 string_data::len = size;
86 string_data::data = new char[string_data::len + 1];
87 std::copy_n(s, string_data::len, string_data::data);
88 string_data::data[string_data::len] = '\0';
91 string() : string(&NUL, 0) {}
92 explicit string(const char* s) : string(s, strlen(s)) {}
93 string(string const& s) : string(s.c_str(), s.size()) {}
96 string_data::len = s.string_data::len;
97 string_data::data = s.string_data::data;
98 s.string_data::len = 0;
99 s.string_data::data = &NUL;
101 explicit string(std::string const& s) : string(s.c_str(), s.size()) {}
104 void assign(const char* s, size_t size)
106 if (string_data::data != &NUL) {
107 delete[] string_data::data;
108 string_data::data = nullptr;
109 string_data::len = 0;
112 string_data::len = size;
113 string_data::data = new char[string_data::len + 1];
114 std::copy_n(s, string_data::len, string_data::data);
115 string_data::data[string_data::len] = '\0';
120 string& operator=(const char* s)
122 assign(s, std::strlen(s));
125 string& operator=(string const& s)
127 assign(s.c_str(), s.size());
130 string& operator=(std::string const& s)
132 assign(s.c_str(), s.size());
137 size_t size() const { return len; }
138 size_t length() const { return len; }
139 bool empty() const { return len != 0; }
140 void shrink_to_fit() { /* Being there, but doing nothing */}
143 char* data() { return string_data::data; }
144 const char* data() const { return string_data::data; }
145 char* c_str() { return string_data::data; }
146 const char* c_str() const { return string_data::data; };
147 reference at(size_type i)
150 throw std::out_of_range("Out of range");
153 const_reference at(size_type i) const
156 throw std::out_of_range("Out of range");
159 reference operator[](size_type i)
163 const_reference operator[](size_type i) const
168 static string_data& to_string_data(string& s) { return s; }
169 operator std::string() const { return std::string(this->c_str(), this->size()); }
172 iterator begin() { return data(); }
173 iterator end() { return data() + size(); }
174 const_iterator begin() const { return data(); }
175 const_iterator end() const { return data() + size(); }
176 const_iterator cbegin() const { return data(); }
177 const_iterator cend() const { return data() + size(); }
178 // (Missing, reverse iterators)
183 string_data::len = 0;
184 string_data::data = &NUL;
187 bool equals(const char* data, std::size_t len) const
189 return this->size() == len
190 && std::memcmp(this->c_str(), data, len) == 0;
193 bool operator==(string const& that) const
195 return this->equals(that.c_str(), that.size());
197 bool operator==(std::string const& that) const
199 return this->equals(that.c_str(), that.size());
201 bool operator==(const char* that) const
203 return this->equals(that, std::strlen(that));
207 bool operator!=(X const& that) const
209 return not (*this == that);
213 int compare(const char* data, std::size_t len) const
215 size_t n = std::min(this->size(), len);
216 int res = memcmp(this->c_str(), data, n);
219 else if (this->size() == len)
221 else if (this->size() < len)
226 int compare(string const& that) const
228 return this->compare(that.c_str(), that.size());
230 int compare(std::string const& that) const
232 return this->compare(that.c_str(), that.size());
234 int compare(const char* that) const
236 return this->compare(that, std::strlen(that));
239 // Define < <= >= > in term of compare():
241 bool operator<(X const& that) const
243 return this->compare(that) < 0;
246 bool operator<=(X const& that) const
248 return this->compare(that) <= 0;
251 bool operator>(X const& that) const
253 return this->compare(that) > 0;
256 bool operator>=(X const& that) const
258 return this->compare(that) >= 0;
263 bool operator==(std::string const& a, string const& b)
268 bool operator!=(std::string const& a, string const& b)
273 bool operator<(std::string const& a, string const& b)
278 bool operator<=(std::string const& a, string const& b)
283 bool operator>(std::string const& a, string const& b)
288 bool operator>=(std::string const& a, string const& b)
295 typedef std::string string;
299 /** Create a C++ string from a C-style format
303 XBT_PUBLIC std::string string_printf(const char* fmt, ...);
305 /** Create a C++ string from a C-style format
309 XBT_PUBLIC std::string string_vprintf(const char* fmt, va_list ap);