ICU 66.1 66.1
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
42U_NAMESPACE_BEGIN
43
61 private:
62 const char* ptr_;
63 int32_t length_;
64
65 public:
70 StringPiece() : ptr_(NULL), length_(0) { }
76 StringPiece(const char* str);
81 StringPiece(const std::string& str)
82 : ptr_(str.data()), length_(static_cast<int32_t>(str.size())) { }
83#ifndef U_HIDE_DRAFT_API
103 template <typename T,
104 typename = typename std::enable_if<
105 std::is_same<decltype(T().data()), const char*>::value &&
106 std::is_same<decltype(T().size()), size_t>::value>::type>
108 : ptr_(str.data()), length_(static_cast<int32_t>(str.size())) {}
109#endif // U_HIDE_DRAFT_API
116 StringPiece(const char* offset, int32_t len) : ptr_(offset), length_(len) { }
123 StringPiece(const StringPiece& x, int32_t pos);
132 StringPiece(const StringPiece& x, int32_t pos, int32_t len);
133
144 const char* data() const { return ptr_; }
150 int32_t size() const { return length_; }
156 int32_t length() const { return length_; }
162 UBool empty() const { return length_ == 0; }
163
168 void clear() { ptr_ = NULL; length_ = 0; }
169
176 void set(const char* xdata, int32_t len) { ptr_ = xdata; length_ = len; }
177
183 void set(const char* str);
184
190 void remove_prefix(int32_t n) {
191 if (n >= 0) {
192 if (n > length_) {
193 n = length_;
194 }
195 ptr_ += n;
196 length_ -= n;
197 }
198 }
199
205 void remove_suffix(int32_t n) {
206 if (n >= 0) {
207 if (n <= length_) {
208 length_ -= n;
209 } else {
210 length_ = 0;
211 }
212 }
213 }
214
219 static const int32_t npos; // = 0x7fffffff;
220
229 StringPiece substr(int32_t pos, int32_t len = npos) const {
230 return StringPiece(*this, pos, len);
231 }
232};
233
241U_EXPORT UBool U_EXPORT2
243
251inline UBool operator!=(const StringPiece& x, const StringPiece& y) {
252 return !(x == y);
253}
254
255U_NAMESPACE_END
256
257#endif /* U_SHOW_CPLUSPLUS_API */
258
259#endif // __STRINGPIECE_H__
A string-like object that points to a sized piece of memory.
Definition: stringpiece.h:60
StringPiece substr(int32_t pos, int32_t len=npos) const
Returns a substring of this StringPiece.
Definition: stringpiece.h:229
UBool empty() const
Returns whether the string is empty.
Definition: stringpiece.h:162
StringPiece(const char *str)
Constructs from a NUL-terminated const char * pointer.
void set(const char *str)
Reset the stringpiece to refer to new data.
StringPiece(const StringPiece &x, int32_t pos, int32_t len)
Substring of another StringPiece.
StringPiece(T str)
Constructs from some other implementation of a string piece class, from any C++ record type that has ...
Definition: stringpiece.h:107
static const int32_t npos
Maximum integer, used as a default value for substring methods.
Definition: stringpiece.h:219
void clear()
Sets to an empty string.
Definition: stringpiece.h:168
const char * data() const
Returns the string pointer.
Definition: stringpiece.h:144
StringPiece()
Default constructor, creates an empty StringPiece.
Definition: stringpiece.h:70
void set(const char *xdata, int32_t len)
Reset the stringpiece to refer to new data.
Definition: stringpiece.h:176
int32_t size() const
Returns the string length.
Definition: stringpiece.h:150
void remove_prefix(int32_t n)
Removes the first n string units.
Definition: stringpiece.h:190
void remove_suffix(int32_t n)
Removes the last n string units.
Definition: stringpiece.h:205
int32_t length() const
Returns the string length.
Definition: stringpiece.h:156
StringPiece(const StringPiece &x, int32_t pos)
Substring of another StringPiece.
StringPiece(const std::string &str)
Constructs from a std::string.
Definition: stringpiece.h:81
UMemory is the common ICU base class.
Definition: uobject.h:115
U_EXPORT UBool operator==(const StringPiece &x, const StringPiece &y)
Global operator == for StringPiece.
UBool operator!=(const StringPiece &x, const StringPiece &y)
Global operator != for StringPiece.
Definition: stringpiece.h:251
#define U_EXPORT
Definition: platform.h:828
C++ API: Central ICU header for including the C++ standard <string> header and for related definition...
int8_t UBool
The ICU boolean type.
Definition: umachine.h:261
C++ API: Common ICU base class UObject.
Basic definitions for ICU, for both C and C++ APIs.
#define NULL
Define NULL if necessary, to nullptr for C++ and to ((void *)0) for C.
Definition: utypes.h:188
#define U_COMMON_API
Set to export library symbols from inside the common library, and to import them from outside.
Definition: utypes.h:300