ICU 67.1  67.1
stringpiece.h
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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 // Copyright (C) 2009-2013, International Business Machines
4 // Corporation and others. All Rights Reserved.
5 //
6 // Copyright 2001 and onwards Google Inc.
7 // Author: Sanjay Ghemawat
8 
9 // This code is a contribution of Google code, and the style used here is
10 // a compromise between the original Google code and the ICU coding guidelines.
11 // For example, data types are ICU-ified (size_t,int->int32_t),
12 // and API comments doxygen-ified, but function names and behavior are
13 // as in the original, if possible.
14 // Assertion-style error handling, not available in ICU, was changed to
15 // parameter "pinning" similar to UnicodeString.
16 //
17 // In addition, this is only a partial port of the original Google code,
18 // limited to what was needed so far. The (nearly) complete original code
19 // is in the ICU svn repository at icuhtml/trunk/design/strings/contrib
20 // (see ICU ticket 6765, r25517).
21 
22 #ifndef __STRINGPIECE_H__
23 #define __STRINGPIECE_H__
24 
30 #include "unicode/utypes.h"
31 
32 #if U_SHOW_CPLUSPLUS_API
33 
34 #include <cstddef>
35 #include <type_traits>
36 
37 #include "unicode/uobject.h"
38 #include "unicode/std_string.h"
39 
40 // Arghh! I wish C++ literals were "string".
41 
42 U_NAMESPACE_BEGIN
43 
61  private:
62  const char* ptr_;
63  int32_t length_;
64 
65  public:
70  StringPiece() : ptr_(nullptr), length_(0) { }
71 
77  StringPiece(const char* str);
78 #ifndef U_HIDE_DRAFT_API
79 #if defined(__cpp_char8_t) || defined(U_IN_DOXYGEN)
80 
85  StringPiece(const char8_t* str) : StringPiece(reinterpret_cast<const char*>(str)) {}
86 #endif
87 
93  StringPiece(std::nullptr_t p) : ptr_(p), length_(0) {}
94 #endif // U_HIDE_DRAFT_API
95 
100  StringPiece(const std::string& str)
101  : ptr_(str.data()), length_(static_cast<int32_t>(str.size())) { }
102 #ifndef U_HIDE_DRAFT_API
103 #if defined(__cpp_lib_char8_t) || defined(U_IN_DOXYGEN)
104 
108  StringPiece(const std::u8string& str)
109  : ptr_(reinterpret_cast<const char*>(str.data())),
110  length_(static_cast<int32_t>(str.size())) { }
111 #endif
112 #endif // U_HIDE_DRAFT_API
113 
114 #ifndef U_HIDE_DRAFT_API
115 
137  template <typename T,
138  typename = typename std::enable_if<
139  (std::is_same<decltype(T().data()), const char*>::value
140 #if defined(__cpp_char8_t)
141  || std::is_same<decltype(T().data()), const char8_t*>::value
142 #endif
143  ) &&
144  std::is_same<decltype(T().size()), size_t>::value>::type>
145  StringPiece(T str)
146  : ptr_(reinterpret_cast<const char*>(str.data())),
147  length_(static_cast<int32_t>(str.size())) {}
148 #endif // U_HIDE_DRAFT_API
149 
156  StringPiece(const char* offset, int32_t len) : ptr_(offset), length_(len) { }
157 #ifndef U_HIDE_DRAFT_API
158 #if defined(__cpp_char8_t) || defined(U_IN_DOXYGEN)
159 
165  StringPiece(const char8_t* str, int32_t len) :
166  StringPiece(reinterpret_cast<const char*>(str), len) {}
167 #endif
168 #endif // U_HIDE_DRAFT_API
169 
176  StringPiece(const StringPiece& x, int32_t pos);
185  StringPiece(const StringPiece& x, int32_t pos, int32_t len);
186 
197  const char* data() const { return ptr_; }
203  int32_t size() const { return length_; }
209  int32_t length() const { return length_; }
215  UBool empty() const { return length_ == 0; }
216 
221  void clear() { ptr_ = nullptr; length_ = 0; }
222 
229  void set(const char* xdata, int32_t len) { ptr_ = xdata; length_ = len; }
230 
236  void set(const char* str);
237 
238 #ifndef U_HIDE_DRAFT_API
239 #if defined(__cpp_char8_t) || defined(U_IN_DOXYGEN)
240 
246  inline void set(const char8_t* xdata, int32_t len) {
247  set(reinterpret_cast<const char*>(xdata), len);
248  }
249 
255  inline void set(const char8_t* str) {
256  set(reinterpret_cast<const char*>(str));
257  }
258 #endif
259 #endif // U_HIDE_DRAFT_API
260 
266  void remove_prefix(int32_t n) {
267  if (n >= 0) {
268  if (n > length_) {
269  n = length_;
270  }
271  ptr_ += n;
272  length_ -= n;
273  }
274  }
275 
281  void remove_suffix(int32_t n) {
282  if (n >= 0) {
283  if (n <= length_) {
284  length_ -= n;
285  } else {
286  length_ = 0;
287  }
288  }
289  }
290 
291 #ifndef U_HIDE_DRAFT_API
292 
299  int32_t find(StringPiece needle, int32_t offset);
300 
308  int32_t compare(StringPiece other);
309 #endif // U_HIDE_DRAFT_API
310 
315  static const int32_t npos; // = 0x7fffffff;
316 
325  StringPiece substr(int32_t pos, int32_t len = npos) const {
326  return StringPiece(*this, pos, len);
327  }
328 };
329 
337 U_EXPORT UBool U_EXPORT2
338 operator==(const StringPiece& x, const StringPiece& y);
339 
347 inline UBool operator!=(const StringPiece& x, const StringPiece& y) {
348  return !(x == y);
349 }
350 
351 U_NAMESPACE_END
352 
353 #endif /* U_SHOW_CPLUSPLUS_API */
354 
355 #endif // __STRINGPIECE_H__
StringPiece(const char *offset, int32_t len)
Constructs from a const char * pointer and a specified length.
Definition: stringpiece.h:156
void remove_prefix(int32_t n)
Removes the first n string units.
Definition: stringpiece.h:266
int32_t size() const
Returns the string length.
Definition: stringpiece.h:203
U_EXPORT UBool operator==(const StringPiece &x, const StringPiece &y)
Global operator == for StringPiece.
UBool empty() const
Returns whether the string is empty.
Definition: stringpiece.h:215
StringPiece(const char8_t *str)
Constructs from a NUL-terminated const char8_t * pointer.
Definition: stringpiece.h:85
StringPiece(std::nullptr_t p)
Constructs an empty StringPiece.
Definition: stringpiece.h:93
StringPiece()
Default constructor, creates an empty StringPiece.
Definition: stringpiece.h:70
StringPiece(const std::string &str)
Constructs from a std::string.
Definition: stringpiece.h:100
StringPiece(T str)
Constructs from some other implementation of a string piece class, from any C++ record type that has ...
Definition: stringpiece.h:145
UBool operator!=(const StringPiece &x, const StringPiece &y)
Global operator != for StringPiece.
Definition: stringpiece.h:347
C++ API: Central ICU header for including the C++ standard <string> header and for related definition...
int32_t length() const
Returns the string length.
Definition: stringpiece.h:209
C++ API: Common ICU base class UObject.
StringPiece substr(int32_t pos, int32_t len=npos) const
Returns a substring of this StringPiece.
Definition: stringpiece.h:325
#define U_EXPORT
Definition: platform.h:828
const char * data() const
Returns the string pointer.
Definition: stringpiece.h:197
void clear()
Sets to an empty string.
Definition: stringpiece.h:221
Basic definitions for ICU, for both C and C++ APIs.
#define U_COMMON_API
Set to export library symbols from inside the common library, and to import them from outside...
Definition: utypes.h:300
StringPiece(const char8_t *str, int32_t len)
Constructs from a const char8_t * pointer and a specified length.
Definition: stringpiece.h:165
A string-like object that points to a sized piece of memory.
Definition: stringpiece.h:60
void remove_suffix(int32_t n)
Removes the last n string units.
Definition: stringpiece.h:281
UMemory is the common ICU base class.
Definition: uobject.h:115
static const int32_t npos
Maximum integer, used as a default value for substring methods.
Definition: stringpiece.h:315
StringPiece(const std::u8string &str)
Constructs from a std::u8string.
Definition: stringpiece.h:108
int8_t UBool
The ICU boolean type.
Definition: umachine.h:261