RWCSubString(3C++) RWCSubString(3C++)
NameRWCSubString - Rogue Wave library class
Synopsis
#include <rw/cstring.h>
RWCString s("test string");
s(6,3); // "tri"
Description
The class RWCSubString allows some subsection of an RWCString to be
addressed by defining a starting position and an extent. For example the
7th through the 11th elements, inclusive, would have a starting position
of 7 and an extent of 5. The specification of a starting position and
extent can also be done in your behalf by such functions as
RWCString::strip() or the overloaded function call operator taking a
regular expression as an argument. There are no public constructors --
RWCSubStrings are constructed by various functions of the RWCString class
and then destroyed immediately. A zero length substring is one with a
defined starting position and an extent of zero. It can be thought of as
starting just before the indicated character, but not including it. It
can be used as an lvalue. A null substring is also legal and is
frequently used to indicate that a requested substring, perhaps through a
search, does not exist. A null substring can be detected with member
function isNull(). However, it cannot be used as an lvalue.
Persistence
None
Example
#include <rw/cstring.h>
#include <rw/rstream.h>
main(){
RWCString s("What I tell you is true.");
// Create a substring and use it as an lvalue:
s(19, 0) = "three times ";
cout << s << endl;
}
Program output:
What I tell you is three times true.
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RWCSubString(3C++) RWCSubString(3C++)
Assignment Operators
RWCSubString&
operator=(const RWCString&);
Assignment from an RWCString. The statements:
RWCString a;
RWCString b;
b(2, 3) = a;
will copy a's data into the substring b(2,3). The number of elements
need not match: if they differ, b will be resized appropriately. Sets
self's extent to be the length of the assigned RWCString. If self is the
null substring, then the statement has no effect. Returns a reference to
self.
RWCSubString&
operator=(const RWCSubString&);
Assignment from an RWCSubString. The statements:
RWCString a;
RWCString b;
b(2, 3) = a(5,5);
will copy 5 characters of a's data into the substring b(2,3). The number
of elements need not match: if they differ, b will be resized
appropriately. Sets self's extent to be the extent of the assigned
RWCSubString. If self is the null substring, then the statement has no
effect. Returns a reference to self.
RWCSubString&
operator=(const char*);
Assignment from a character string. Example:
RWCString str("Mary had a lamb");
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RWCSubString(3C++) RWCSubString(3C++)
char dat[] = "Perrier";
str(11,4) = dat; // "Mary had a Perrier"
Note that the number of characters selected need not match: if they
differ, str will be resized appropriately. Sets self's extent to be the
strlen() of the assigned character string. If self is the null
substring, then the statement has no effect. Returns a reference to
self.
Indexing Operators
char&
operator[](size_t i);
char
operator[](size_t i) const;
Returns the ith character of the substring. The first variant can be
used as an lvalue, the second cannot. The index i must be between zero
and the length of the substring, less one. Bounds checking is performed:
if the index is out of range, then an exception of type RWBoundsErr will
occur.
char&
operator()(size_t i);
char
operator()(size_t i) const;
Returns the ith character of the substring. The first variant can be
used as an lvalue, the second cannot. The index i must be between zero
and the length of the substring, less one. Bounds checking is enabled by
defining the pre-processor macro RWBOUNDS_CHECK before including
<rw/cstring.h>. In this case, if the index is out of range, then an
exception of type RWBoundsErr will occur.
Public Member Functions
RWBoolean
isNull() const;
Returns TRUE if this is a null substring.
size_t
length() const;
Returns the extent (i.e., length) of the RWCSubString.
RWBoolean
operator!() const;
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RWCSubString(3C++) RWCSubString(3C++)
Returns TRUE if this is a null substring.
size_t
start() const;
Returns the starting element of the RWCSubString.
void
toLower();
Changes all upper-case letters in self to lower-case. Uses the standard
C library function tolower().
void
toUpper();
Changes all lower-case letters in self to upper-case. Uses the standard
C library function toupper().
Global Logical Operators
RWBoolean
operator==(const RWCSubString&, const RWCSubString&);
RWBoolean
operator==(const RWCString&, const RWCSubString&);
RWBoolean
operator==(const RWCSubString&, const RWCString& );
RWBoolean
operator==(const char*, const RWCSubString&);
RWBoolean
operator==(const RWCSubString&, const char* );
Returns TRUE if the substring is lexicographically equal to the character
string or RWCString argument. Case sensitivity is exact.
RWBoolean
operator!=(const RWCString&, const RWCString& );
RWBoolean
operator!=(const RWCString&, const RWCSubString&);
RWBoolean
operator!=(const RWCSubString&, const RWCString& );
RWBoolean
operator!=(const char*, const RWCString& );
RWBoolean
operator!=(const RWCString&, const char* );
Returns the negation of the respective operator==().
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