SourcePro® API Reference Guide

 
List of all members | Public Types | Public Member Functions | Related Functions
RWUConstStringIterator Class Reference

Provides read-only access to the code points encoded by the code units within an RWBasicUString. More...

#include <rw/i18n/RWUConstStringIterator.h>

Public Types

typedef int difference_type
 
typedef std::bidirectional_iterator_tag iterator_category
 
typedef value_typepointer
 
typedef value_typereference
 
typedef size_t size_type
 
typedef RWUChar32 value_type
 

Public Member Functions

 RWUConstStringIterator ()
 
 RWUConstStringIterator (const RWBasicUString &ustr)
 
 RWUConstStringIterator (const RWUConstStringIterator &iter)
 
 RWUConstStringIterator (const RWUStringIterator &iter)
 
void advanceCodePoints (int offset)
 
const RWUChar16data () const
 
 operator size_t () const
 
RWUChar32 operator* () const
 
RWUConstStringIteratoroperator++ ()
 
RWUConstStringIterator operator++ (int)
 
RWUConstStringIteratoroperator-- ()
 
RWUConstStringIterator operator-- (int)
 
RWUConstStringIteratoroperator= (const RWUConstStringIterator &iter)
 

Related Functions

(Note that these are not member functions.)

bool operator!= (const RWUConstStringIterator &lhs, const RWUConstStringIterator &rhs)
 
bool operator!= (const RWUConstStringIterator &lhs, const RWUStringIterator &rhs)
 
bool operator== (const RWUConstStringIterator &lhs, const RWUConstStringIterator &rhs)
 
bool operator== (const RWUConstStringIterator &lhs, const RWUStringIterator &rhs)
 

Detailed Description

RWUConstStringIterator provides read-only access to the code points encoded by the code units within an RWBasicUString. Code points within a given string are accessed in forward or reverse order, starting from the beginning or end of the string, respectively.

Attempting to dereference or advance an iterator that is positioned past the end of the string, such as the iterator returned by RWUString::endCodePointIterator(), throws RWBoundsErr.

Instances of RWUConstStringIterator are returned from const RWUString objects, and from instances of classes such as RWUBreakSearch. These classes return RWUConstStringIterator instances because the instances cannot be used to modify the source string.

Bounds Checking

Bounds checking always occurs when repositioning or dereferencing an iterator. Any attempt to dereference an iterator that is in the past-the-end condition produces an RWBoundsErr exception.

Conversion Errors

An RWUConstStringIterator converts code units into code points. Code points greater than 0xFFFF are encoded as a pair of surrogate code units within the string. An RWUStringIterator cannot advance over or dereference an incomplete surrogate pair. An iterator throws an RWConversionErr exception if an incomplete surrogate pair is encountered.

Example
#include <rw/i18n/RWUConstStringIterator.h>
#include <rw/i18n/RWUString.h>
#include <iostream>
int main()
{
// "Hello,\n world.\n";
RWUChar16 buf[16] = { 0x0048, 0x0065, 0x006c, 0x006c, 0x006f,
0x002c, 0x000d, 0x0020, 0x0077, 0x006f,
0x0072, 0x006c, 0x0064, 0x002e, 0x000d,
0x0000 };
// Create the RWUString from the buffer
RWUString str(buf);
const RWUString& strRef = str;
// Iterate backward over all code points in the string
while (it != strRef.beginCodePointIterator()) {
--it;
std::cout << std::hex << int(*it) << std::endl;
} // while
return 0;
} // main

Program Output:

d
2e
64
6c
72
6f
77
20
d
2c
6f
6c
6c
65
48
See also
RWBasicUString, RWUString, RWUStringIterator, RWUBreakSearch

Member Typedef Documentation

Declares an alias for the type used to represent iterator offsets and differences.

typedef std::bidirectional_iterator_tag RWUConstStringIterator::iterator_category

Declares this class to be a C++ Standard Library-compatible bidirectional iterator.

Declares an alias for the value_type pointer.

Declares an alias for the value_type reference.

Declares an alias for the type used to represent sizes and indices.

Declares an alias for the value type returned by this iterator class.

Constructor & Destructor Documentation

RWUConstStringIterator::RWUConstStringIterator ( )
inline

Constructs a null, non-dereferencable iterator. The instance cannot be used until a dereferencable iterator is assigned to it. Any attempt to reposition or dereference a null iterator will cause an RWBoundsErr exception to be thrown.

RWUConstStringIterator::RWUConstStringIterator ( const RWBasicUString ustr)

Constructs an RWUConstStringIterator that is positioned at the first element of ustr, or past-the-end of ustr if ustr is empty.

RWUConstStringIterator::RWUConstStringIterator ( const RWUConstStringIterator iter)
inline

Constructs an RWUConstStringIterator that references the same string and offset as iter.

RWUConstStringIterator::RWUConstStringIterator ( const RWUStringIterator iter)

Constructs an RWUConstStringIterator from the given RWUStringIterator iter.

Note
There is no corresponding conversion from RWUConstStringIterator to RWUStringIterator. This preserves const correctness for the iterator classes.

Member Function Documentation

void RWUConstStringIterator::advanceCodePoints ( int  offset)

Advances self by offset code points.

Exceptions
RWBoundsErrThrown if self is advanced before the first element or after one past the last element in the string. If offset is negative, the iterator is left pointing at the first element in the string. If offset is positive, the iterator is left pointing one past the last element in the string. RWBoundsErr is also thrown if self is null and not dereferencable.
RWConversionErrThrown if an incomplete surrogate pair is encountered where either the high surrogate or the low surrogate code unit is missing. If offset is negative, the iterator is positioned at the code unit immediately preceding the unpaired surrogate code unit, or at the first code unit of the string if the unpaired surrogate is the first code unit in the string. If offset is positive, the iterator is positioned at the code unit immediately following the unpaired surrogate code unit, or one past the last code unit of the string if the unpaired surrogate is the last code unit in the string.
const RWUChar16* RWUConstStringIterator::data ( ) const

Returns a pointer to the string contents at the location referenced by self.

The storage referenced by this pointer is owned by the RWBasicUString associated with this iterator. This storage may not be deleted or modified. The pointer becomes invalid if the RWBasicUString is modified or destroyed.

RWUConstStringIterator::operator size_t ( ) const
inline

Returns the current code unit offset of self.

RWUChar32 RWUConstStringIterator::operator* ( ) const

Returns the value of the code point currently referenced by self.

Exceptions
RWBoundsErrThrown if self is null or otherwise references a position outside the bounds of the string.
RWConversionErrThrown if the code unit sequence found at the current iterator position contains an incomplete surrogate pair where either the high surrogate or the low surrogate code unit is missing.
RWUConstStringIterator& RWUConstStringIterator::operator++ ( )

Advances self to the next code point in the string and returns a reference to self.

Exceptions
RWBoundsErrThrown if self is already positioned one past the last code point in the string, or if self is null. The iterator position is left unchanged.
RWConversionErrThrown if the code unit sequence found at the current iterator position contains an incomplete surrogate pair where either the high surrogate or the low surrogate code unit is missing. Self is left pointing at the code unit immediately following the unpaired surrogate code unit, or one past the last code unit of the string if the unpaired surrogate is the last code unit in the string.
RWUConstStringIterator RWUConstStringIterator::operator++ ( int  )
inline

Advances self to the next code point in the string, and returns a copy of the previous value of self.

Exceptions
RWBoundsErrThrown if self is already positioned one past the last code point in the string, or if self is null. The iterator position is left unchanged.
RWConversionErrThrown if the code unit sequence found at the current iterator position contains an incomplete surrogate pair where either the high surrogate or the low surrogate code unit is missing. Self is left pointing at the code unit immediately following the unpaired surrogate code unit, or one past the last code unit of the string if the unpaired surrogate is the last code unit in the string.
RWUConstStringIterator& RWUConstStringIterator::operator-- ( )

Advances self to the preceding code point in the string and returns a reference to self.

Exceptions
RWBoundsErrThrown if self is already positioned at the beginning of the string, or if self is null. The iterator position is left unchanged.
RWConversionErrThrown if the code unit sequence found at the current iterator position contains an incomplete surrogate pair where either the high surrogate or the low surrogate code unit is missing. Self is left pointing at the unpaired code unit.
RWUConstStringIterator RWUConstStringIterator::operator-- ( int  )
inline

Advances self to the preceding code point in the string and returns a copy of the previous value of self.

Exceptions
RWBoundsErrThrown if self is already positioned at the beginning of the string, or if self is null. The iterator position is left unchanged.
RWConversionErrThrown if the code unit sequence found at the current iterator position contains an incomplete surrogate pair where either the high surrogate or the low surrogate code unit is missing. Self is left pointing at the unpaired code unit.
RWUConstStringIterator & RWUConstStringIterator::operator= ( const RWUConstStringIterator iter)
inline

Changes self so it references the same string and offset as iter, and returns a reference to self.

Friends And Related Function Documentation

bool operator!= ( const RWUConstStringIterator lhs,
const RWUConstStringIterator rhs 
)
related

Returns true if the two iterators reference different RWUString objects, or if the code point offsets referenced by the iterators are different; otherwise, false.

bool operator!= ( const RWUConstStringIterator lhs,
const RWUStringIterator rhs 
)
related

Returns true if the two iterators reference different RWUString objects, or if the code point offsets referenced by the iterators are different; otherwise, false.

bool operator== ( const RWUConstStringIterator lhs,
const RWUConstStringIterator rhs 
)
related

Returns true if both iterators reference the same RWUString, and are positioned at the same code point offset within the RWUString; otherwise, false.

bool operator== ( const RWUConstStringIterator lhs,
const RWUStringIterator rhs 
)
related

Returns true if both iterators reference the same RWUString, and are positioned at the same code point offset within RWUString; otherwise, false.

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