ICU 65.1 65.1

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
60 class U_COMMON_API StringPiece : public UMemory {
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
84
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>
107 StringPiece(T str)
108 : ptr_(str.data()), length_(static_cast<int32_t>(str.size())) {}
109 #endif // U_HIDE_DRAFT_API
110
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
241 U_EXPORT UBool U_EXPORT2
242 operator==(const StringPiece& x, const StringPiece& y);
243
251 inline UBool operator!=(const StringPiece& x, const StringPiece& y) {
252 return !(x == y);
253 }
254
255 U_NAMESPACE_END
256
257 #endif /* U_SHOW_CPLUSPLUS_API */
258
259 #endif // __STRINGPIECE_H__
icu::StringPiece::StringPiece
StringPiece(const char *offset, int32_t len)
Constructs from a const char * pointer and a specified length.
Definition: stringpiece.h:116
icu::StringPiece::remove_prefix
void remove_prefix(int32_t n)
Removes the first n string units.
Definition: stringpiece.h:190
icu::StringPiece::size
int32_t size() const
Returns the string length.
Definition: stringpiece.h:150
icu::operator==
U_EXPORT UBool operator==(const StringPiece &x, const StringPiece &y)
Global operator == for StringPiece.
icu::StringPiece::empty
UBool empty() const
Returns whether the string is empty.
Definition: stringpiece.h:162
icu::StringPiece::StringPiece
StringPiece()
Default constructor, creates an empty StringPiece.
Definition: stringpiece.h:70
icu::StringPiece::StringPiece
StringPiece(const std::string &str)
Constructs from a std::string.
Definition: stringpiece.h:81
icu::StringPiece::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
icu::operator!=
UBool operator!=(const StringPiece &x, const StringPiece &y)
Global operator != for StringPiece.
Definition: stringpiece.h:251
NULL
#define NULL
Define NULL if necessary, to nullptr for C++ and to ((void *)0) for C.
Definition: utypes.h:188
std_string.h
C++ API: Central ICU header for including the C++ standard <string> header and for related definition...
icu::StringPiece::length
int32_t length() const
Returns the string length.
Definition: stringpiece.h:156
uobject.h
C++ API: Common ICU base class UObject.
icu::StringPiece::substr
StringPiece substr(int32_t pos, int32_t len=npos) const
Returns a substring of this StringPiece.
Definition: stringpiece.h:229
U_EXPORT
#define U_EXPORT
Definition: platform.h:828
icu::StringPiece::data
const char * data() const
Returns the string pointer.
Definition: stringpiece.h:144
icu::StringPiece::clear
void clear()
Sets to an empty string.
Definition: stringpiece.h:168
utypes.h
Basic definitions for ICU, for both C and C++ APIs.
U_COMMON_API
#define U_COMMON_API
Set to export library symbols from inside the common library, and to import them from outside...
Definition: utypes.h:300
icu::StringPiece
A string-like object that points to a sized piece of memory.
Definition: stringpiece.h:60
icu::StringPiece::remove_suffix
void remove_suffix(int32_t n)
Removes the last n string units.
Definition: stringpiece.h:205
icu::UMemory
UMemory is the common ICU base class.
Definition: uobject.h:115
icu::StringPiece::npos
static const int32_t npos
Maximum integer, used as a default value for substring methods.
Definition: stringpiece.h:219
UBool
int8_t UBool
The ICU boolean type.
Definition: umachine.h:261