|
VMS Help CXXLSTD, string *Conan The Librarian |
Standard C++ Library
Copyright 1996, Rogue Wave Software, Inc.
NAME
basic_string,string - A templated class for handling sequences of
character-like entities. string and wstring are specialized
versions of basic_string for chars and wchar_ts, respectively.
This page describes the ANSI basic_string class. If you would like
information on the pre-ANSI string class, use the command:
help cxxl
typedef basic_string <char> string;
typedef basic_string <wchar_t> wstring;
SYNOPSIS
#include <string>
template <class charT,
class traits = char_traits<charT>,
class Allocator = allocator<charT> >
class basic_string;
DESCRIPTION
basic_string<charT, traits, Allocator> is a homogeneous collection
of character-like entities. It provides general string
functionality such as compare, append, assign, insert, remove, and
replace , along with various searches. basic_string also functions
as an STL sequence container, providing random access
iterators. This allows some of the generic algorithms to apply
to strings.
Any underlying character-like type may be used as long as an
appropriate string_char_traits class is provided or the default
traits class is applicable.
INTERFACE
template <class charT,
class traits = char_traits<charT>,
class Allocator = allocator<charT> >
class basic_string {
public:
// Types
typedef traits traits_type;
typedef typename traits::char_type value_type;
typedef Allocator allocator_type;
typename size_type;
typename difference_type;
typename reference;
typename const_reference;
typename pointer;
typename const_pointer;
typename iterator;
typename const_iterator;
typename const_reverse_iterator;
typename reverse_iterator;
static const size_type npos = -1;
// Constructors/Destructors
explicit basic_string(const Allocator& = Allocator());
basic_string (const basic_string<charT, traits, Allocator>&);
basic_string(const basic_string&, size_type, size_type = npos);
basic_string(const charT*, size_type,
const Allocator& = Allocator());
basic_string(const charT*, Allocator& = Allocator());
basic_string(size_type, charT,
const Allocator& = Allocator());
template <class InputIterator>
basic_string(InputIterator, InputIterator,
const Allocator& = Allocator());
~basic_string();
// Assignment operators
basic_string& operator=(const basic_string&);
basic_string& operator=(const charT*);
basic_string& operator=(charT);
// Iterators
iterator begin();
const_iterator begin() const;
iterator end();
const_iterator end() const;
reverse_iterator rbegin();
const_reverse_iterator rbegin() const;
reverse_iterator rend();
const_reverse_iterator rend() const;
// Capacity
size_type size() const;
size_type length() const;
size_type max_size() const;
void resize(size_type, charT);
void resize(size_type);
size_type capacity() const;
void reserve(size_type);
bool empty() const;
// Element access
const_reference operator[](size_type) const;
reference operator[](size_type);
const_reference at(size_type) const;
reference at(size_type);
// Modifiers
basic_string& operator+=(const basic_string&);
basic_string& operator+=(const charT*);
basic_string& operator+=(charT);
basic_string& append(const basic_string&);
basic_string& append(const basic_string&,
size_type, size_type);
basic_string& append(const charT*, size_type);
basic_string& append(const charT*);
basic_string& append(size_type, charT);
template<class InputIterator>
basic_string& append(InputIterator, InputIterator);
basic_string& assign(const basic_string&);
basic_string& assign(const basic_string&,
size_type, size_type);
basic_string& assign(const charT*, size_type);
basic_string& assign(const charT*);
basic_string& assign(size_type, charT);
template<class InputIterator>
basic_string& assign(InputIterator, InputIterator);
basic_string& insert(size_type, const basic_string&);
basic_string& insert(size_type, const basic_string&,
size_type, size_type);
basic_string& insert(size_type, const charT*, size_type);
basic_string& insert(size_type, const charT*);
basic_string& insert(size_type, size_type, charT);
iterator insert(iterator, charT = charT());
void insert(iterator, size_type, charT);
template<class InputIterator>
void insert(iterator, InputIterator,
InputIterator);
basic_string& erase(size_type = 0, size_type= npos);
iterator erase(iterator);
iterator erase(iterator, iterator);
basic_string& replace(size_type, size_type,
const basic_string&);
basic_string& replace(size_type, size_type,
const basic_string&,
size_type, size_type);
basic_string& replace(size_type, size_type,
const charT*, size_type);
basic_string& replace(size_type, size_type,
const charT*);
basic_string& replace(size_type, size_type,
size_type, charT);
basic_string& replace(iterator, iterator,
const basic_string&);
basic_string& replace(iterator, iterator,
const charT*, size_type);
basic_string& replace(iterator, iterator,
const charT*);
basic_string& replace(iterator, iterator,
size_type, charT);
template<class InputIterator>
basic_string& replace(iterator, iterator,
InputIterator, InputIterator);
size_type copy(charT*, size_type, size_type = 0);
void swap(basic_string<charT, traits, Allocator>&);
// String operations
const charT* c_str() const;
const charT* data() const;
const allocator_type& get_allocator() const;
size_type find(const basic_string&,
size_type = 0) const;
size_type find(const charT*,
size_type, size_type) const;
size_type find(const charT*, size_type = 0) const;
size_type find(charT, size_type = 0) const;
size_type rfind(const basic_string&,
size_type = npos) const;
size_type rfind(const charT*,
size_type, size_type) const;
size_type rfind(const charT*,
size_type = npos) const;
size_type rfind(charT, size_type = npos) const;
size_type find_first_of(const basic_string&,
size_type = 0) const;
size_type find_first_of(const charT*,
size_type, size_type) const;
size_type find_first_of(const charT*,
size_type = 0) const;
size_type find_first_of(charT, size_type = 0) const;
size_type find_last_of(const basic_string&,
size_type = npos) const;
size_type find_last_of(const charT*,
size_type, size_type) const;
size_type find_last_of(const charT*, size_type = npos) const;
size_type find_last_of(charT, size_type = npos) const;
size_type find_first_not_of(const basic_string&,
size_type = 0) const;
size_type find_first_not_of(const charT*,
size_type, size_type) const;
size_type find_first_not_of(const charT*, size_type = 0) const;
size_type find_first_not_of(charT, size_type = 0) const;
size_type find_last_not_of(const basic_string&,
size_type = npos) const;
size_type find_last_not_of(const charT*,
size_type, size_type) const;
size_type find_last_not_of(const charT*,
size_type = npos) const;
size_type find_last_not_of(charT, size_type = npos) const;
basic_string substr(size_type = 0, size_type = npos) const;
int compare(const basic_string&) const;
int compare(size_type, size_type, const basic_string&) const;
int compare(size_type, size_type, const basic_string&,
size_type, size_type) const;
int compare(size_type, size_type, charT*) const;
int compare(charT*) const;
int compare(size_type, size_type, const charT*, size_type) const;
};
// Non-member Operators
template <class charT, class traits, class Allocator>
basic_string operator+ (const basic_string&,
const basic_string&);
template <class charT, class traits, class Allocator>
basic_string operator+ (const charT*, const basic_string&);
template <class charT, class traits, class Allocator>
basic_string operator+ (charT, const basic_string&);
template <class charT, class traits, class Allocator>
basic_string operator+ (const basic_string&, const charT*);
template <class charT, class traits, class Allocator>
basic_string operator+ (const basic_string&, charT);
template <class charT, class traits, class Allocator>
bool operator== (const basic_string&, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator== (const charT*, const basic_string&);
template <class charT, class traits , class Allocator>
bool operator== (const basic_string&, const charT*);
template <class charT, class traits, class Allocator>
bool operator< (const basic_string&, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator< (const charT*, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator< (const basic_string&, const charT*);
template <class charT, class traits, class Allocator>
bool operator!= (const basic_string&, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator!= (const charT*, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator!= (const basic_string&, const charT*);
template <class charT, class traits, class Allocator>
bool operator> (const basic_&, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator> (const charT*, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator> (const basic_string&, const charT*);
template <class charT, class traits, class Allocator>
bool operator<= (const basic_string&, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator<= (const charT*, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator<= (const basic_string&, const charT*);
template <class charT, class traits, class Allocator>
bool operator>= (const basic_string&, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator>= (const charT*, const basic_string&);
template <class charT, class traits, class Allocator>
bool operator>= (const basic_string&, const charT*);
template <class charT, class traits, class Allocator>
void swap(basic_string<charT,traits,Allocator>& a,
basic_string<charT,traits,Allocator>& b);
template<class charT, class traits, class Allocator>
istream& operator>> (istream&, basic_string&);
template <class charT, class traits, class Allocator>
ostream& operator<< (ostream&, const basic_string&);
template <class Stream, class charT,
class traits, class Allocator>
Stream& getline (Stream&, basic_string&, charT);
CONSTRUCTORS AND DESTRUCTORS
In all cases, the Allocator parameter will be used for storage
management.
explicit
basic_string (const Allocator& a = Allocator());
The default constructor. Creates a basic_string with the following
effects:
data() a non-null pointer that is copyable and can have 0 added
to it
size() 0
capacity() an unspecified value
basic_string (const basic_string<T, traits, Allocator>& str);
Copy constructor. Creates a string that is a copy of str.
basic_string (const basic_string &str, size_type pos,
size_type n= npos);
Creates a string if pos<=size() and determines length
rlen of initial string value as the smaller of n and
str.size() - pos. This has the following effects:
data() points at the first element of an allocated
copy of rlen elements of the string controlled
by str beginning at position pos
size() rlen
capacity() a value at least as large as size()
get_allocator() str.get_allocator()
An out_of_range exception will be thrown if
pos>str.size().
basic_string (const charT* s, size_type n,
const Allocator& a = Allocator());
Creates a string that contains the first n characters
of s. s must not be a NULL pointer. The effects of
this constructor are:
data() points at the first element of an allocated
copy of the array whose first element is
pointed at by s
size() n
capacity() a value at least as large as size()
An out_of_range exception will be thrown if n == npos.
basic_string (const charT * s,
const Allocator& a = Allocator());
Constructs a string containing all characters in s up
to, but not including, a traits::eos() character.
s must not be a null pointer. The effects of this
constructor are:
data() points at the first element of an allocated
copy of the array whose first element is
pointed at by s
size() traits::length(s)
capacity() a value at least as large as size()
basic_string (size_type n, charT c,
const Allocator& a = Allocator());
Constructs a string containing n repetitions of c. A
length_error exception is thrown if n == npos. The
effects of this constructor are:
data() points at the first element of an allocated
array of n elements, each storing the
initial value c
size() n
capacity() a value at least as large as size()
template <class InputIterator>
basic_string (InputIterator first, InputIterator last,
const Allocator& a = Allocator());
Creates a basic_string of length last - first,
filled with all values obtained by dereferencing
the InputIterators on the range [first, last).
The effects of this constructor are:
data() points at the first element of an allocated
copy of the elements in the range
[first,last)
size() distance between first and last
capacity() a value at least as large as size()
~basic_string ();
Releases any allocated memory for this basic_string.
OPERATORS
basic_string&
operator= (const basic_string& str);
Assignment operator. Sets the contents of this string to be the
same as str. The effects of operator= are:
data() points at the first element of an allocated copy of
the array whose first element is pointed at
by str.size()
size() str.size()
capacity() a value at least as large as size()
basic_string&
operator= (const charT * s);
Assignment operator. Sets the contents of this string to be the
same as s up to, but not including, the traits::eos() character.
basic_string&
operator= (charT c);
Assignment operator. Sets the contents of this string to be equal
to the single charT c.
const_reference
operator[] (size_type pos) const;
reference
operator[] (size_type pos);
If pos < size(), returns the element at position pos in this
string. If pos == size(), the const version returns traits::eos(),
the behavior of the non-const version is undefined. The
reference returned by either version is invalidated by any
call to c_str(), data(), or any non-const member function
for the object.
basic_string&
operator+= (const basic_string& s);
basic_string&
operator+= (const charT* s);
basic_string&
operator+= (charT c);
Concatenates a string onto the current contents of this string.
The second member operator uses traits::length() to determine the
number of elements from s to add. The third member operator
adds the single character c. All return a reference to this
string after completion.
ITERATORS
iterator begin ();
const_iterator begin () const;
Return an iterator initialized to the first element of the string.
iterator end ();
const_iterator end () const;
Return an iterator initialized to the position after the last
element of the string.
reverse_iterator rbegin ();
const_reverse_iterator rbegin () const;
Returns an iterator equivalent to reverse_iterator(end()).
reverse_iterator rend ();
const_reverse_iterator rend () const;
Returns an iterator equivalent to reverse_iterator(begin()).
ALLOCATOR
const allocator_type get_allocator () const;
Returns a copy of the allocator used by self for storage management.
MEMBER FUNCTIONS
basic_string&
append (const basic_string& s, size_type pos, size_type npos);
basic_string&
append (const basic_string& s);
basic_string&
append (const charT* s, size_type n);
basic_string&
append (const charT* s);
basic_string&
append (size_type n, charT c );
template<class InputIterator>
basic_string&
append (InputIterator first, InputIterator last);
Append another string to the end of this string. The first two
functions append the lesser of n and s.size() - pos characters of s,
beginning at position pos to this string. The second member will
throw an out_of_range exception if pos > str.size(). The third
member appends n characters of the array pointed to by s. The
fourth variation appends elements from the array pointed to
by s up to, but not including, a traits::eos() character.
The fifth variation appends n repetitions of c. The final
append function appends the elements specified in the
range [first, last).
All functions will throw a length_error exception if the
resulting length will exceed max_size(). All return a
reference to this string after completion.
basic_string&
assign (const basic_string& s);
basic_string&
assign (const basic_string& s,
size_type pos, size_type n);
basic_string&
assign (const charT* s, size_type n);
basic_string&
assign (const charT* s);
basic_string&
assign (size_type n, charT c );
template<class InputIterator>
basic_string&
assign (InputIterator first, InputIterator last);
Replace the value of this string with the value of another.
All versions of the function assign values to this string. The
first two variations assign the lesser of n and s.size() - pos
characters of s, beginning at position pos. The second
variation throws an out_of_range exception if pos > str.size().
The third version of the function assigns n characters of
the array pointed to by s. The fourth version assigns elements
from the array pointed to by s up to, but not including, a
traits::eos() character. The fifth assigns one or n
repetitions of c. The last variation assigns the members
specified by the range [first, last).
All functions will throw a length_error exception if the
resulting length will exceed max_size(). All return a
reference to this string after completion.
const_reference
at (size_type pos) const;
reference
at (size_type pos);
If pos < size(), returns the element at position pos in this
string. Otherwise, an out_of_range exception is thrown.
size_type
capacity () const;
Returns the current storage capacity of the string. This is
guaranteed to be at least as large as size().
int
compare (const basic_string& str);
Returns the result of a lexicographical comparison between
elements of this string and elements of str. The return value
is:
<0 if size() < str.size()
0 if size() == str.size()
>0 if size() > str.size()
int
compare (size_type pos1, size_type n1,
const basic_string& str) const;
int
compare (size_type pos1, size_type n1, const basic_string& str,
size_type pos2, size_type n2) const;
int
compare (charT* s) const;
int
compare (size_type pos, size_type n1, charT* s) const;
int
compare (size_type pos, size_type n1, charT* s,
size_type n2) const;
Return the result of a lexicographical comparison between
elements of this string and a given comparison string. The
members return, respectively:
compare (str)
compare (basic_string (str, pos2, n2))
compare (basic_string(s))
compare (basic_string(s, npos))
compare (basic_string (s,n2))
size_type
copy (charT* s, size_type n, size_type pos = 0) const;
Replaces elements in memory with copies of elements from this
string. An out_of_range exception will be thrown if pos > size().
The lesser of n and size() - pos elements of this string,
starting at position pos are copied into the array pointed
to by s. No terminating null is appended to s.
const charT*
c_str () const;
const charT*
data () const;
Return a pointer to the initial element of an array whose first
size() elements are copies of the elements in this string.
A traits::eos() element is appended to the end. The elements of
the array may not be altered, and the returned pointer is only
valid until a non-const member function of this string is called.
If size() is zero, the data() function returns a NULL pointer.
bool empty () const;
Returns size() == 0.
basic_string&
erase (size_type pos = 0, size_type n = npos);
iterator
erase (iterator p);
iterator
erase (iterator first, iterator last);
This function removes elements from the string, collapsing
the remaining elements, as necessary, to remove any space
left empty. The first version of the function removes the
smaller of n and size() - pos starting at position pos.
An out_of_range exception will be thrown if pos >
size(). The second version requires that p is a valid
iterator on this string, and removes the character referred to
by p. The last version of erase requires that both first and
last are valid iterators on this string, and removes the
characters defined by the range [first,last). The destructors
for all removed characters are called. All versions of erase
return a reference to this string after completion.
size_type
find (const basic_string& str, size_type pos = 0) const;
Searches for the first occurrence of the substring specified by
str in this string, starting at position pos. If found, it
returns the index of the first character of the matching
substring. If not found, returns npos. Equality is defined by
traits::eq().
size_type
find (const charT* s, size_type pos, size_type n) const;
size_type
find (const charT* s, size_type pos = 0) const;
size_type
find (charT c, size_type pos = 0) const;
Search for the first sequence of characters in this string that
match a specified string. The variations of this function
return, respectively:
find(basic_string(s,n), pos)
find(basic_string(s), pos)
find(basic_string(1, c), pos)
size_type
find_first_not_of (const basic_string& str,
size_type pos = 0) const
Searches for the first element of this string at or
after position pos that is not equal to any element of str. If
found, find_first_not_of returns the index of the non-matching
character. If all of the characters match, the function returns
npos. Equality is defined by traits::eq().
size_type
find_first_not_of (const charT* s,
size_type pos, size_type n) const;
size_type
find_first_not_of (const charT* s,
size_type pos = 0) const;
size_type
find_first_not_of (charT c, size_type pos = 0) const;
Search for the first element in this string at or after position
pos that is not equal to any element of a given set of
characters. The members return, respectively:
find_first_not_of(basic_string(s,n), pos)
find_first_not_of(basic_string(s), pos)
find_first_not_of(basic_string(1, c), pos)
size_type
find_first_of(const basic_string& str,
size_type pos = 0) const;
Searches for the first occurrence at or after position pos
of any element of str in this string. If found, the index
of this matching character is returned. If not found, npos is
returned. Equality is defined by traits::eq().
size_type
find_first_of(const charT* s, size_type pos,
size_type n) const;
size_type
find_first_of(const charT* s, size_type pos = 0) const;
size_type
find_first_of (charT c, size_type pos = 0) const;
Search for the first occurrence in this string of any element in
a specified string. The find_first_of variations return,
respectively:
find_first_of(basic_string(s,n), pos)
find_first_of(basic_string(s), pos)
find_first_of(basic_string(1, c), pos)
size_type
find_last_not_of(const basic_string& str,
size_type pos = npos) const;
Searches for the last element of this string at or before
position pos that is not equal to any element of str. If
find_last_not_of finds a non-matching element, it returns the
index of the character. If all the elements match, the
function returns npos. Equality is defined by traits::eq().
size_type
find_last_not_of(const charT* s,
size_type pos, size_type n) const;
size_type
find_last_not_of(const charT* s, size_type pos = npos) const;
size_type
find_last_not_of(charT c, size_type pos = npos) const;
Search for the last element in this string at or before position
pos that is not equal to any element of a given set of
characters. The members return, respectively:
find_last_not_of(basic_string(s,n), pos)
find_last_not_of(basic_string(s), pos)
find_last_not_of(basic_string(1, c), pos)
size_type
find_last_of(const basic_string& str,
size_type pos = npos) const;
Searches for the last occurrence of any element of str at or
before position pos in this string. If found,
find_last_of returns the index of the matching character. If
not found find_last_of returns npos. Equality is defined by
traits::eq().
size_type
find_last_of(const charT* s, size_type pos,
size_type n) const;
size_type
find_last_of(const charT* s, size_type pos = npos) const;
size_type
find_last_of(charT c, size_type pos = npos) const;
Search for the last occurrence in this string of any element
in a specified string. The members return, respectively:
find_last_of(basic_string(s,n), pos)
find_last_of(basic_string(s), pos)
find_last_of(basic_string(1, c), pos)
basic_string&
insert(size_type pos1, const basic_string& s);
basic_string&
insert(size_type pos, const basic_string& s,
size_type pos2 = 0, size_type n = npos);
basic_string&
insert(size_type pos, const charT* s, size_type n);
basic_string&
insert(size_type pos, const charT* s);
basic_string&
insert(size_type pos, size_type n, charT c);
Insert additional elements at position pos in this string. All
of the variants of this function will throw an out_of_range
exception if pos > size(). All variants will also throw a
length_error if the resulting string will exceed max_size().
Elements of this string will be moved apart as necessary to
accommodate the inserted elements. All return a reference to this
string after completion.
The second variation of this function inserts the lesser of n and
s.size() - pos2 characters of s, beginning at position pos2 in
this string. This version will throw an out_of_range
exception if pos2 > s.size(). The third version inserts n
characters of the array pointed to by s. The fourth
inserts elements from the array pointed to by s up
to, but not including, a traits::eos() character.
Finally, the fifth variation inserts n repetitions of c.
iterator
insert(iterator p, charT c = charT());
void
insert(iterator p, size_type n, charT c);
template<class InputIterator>
void
insert(iterator p, InputIterator first, InputIterator last);
Insert additional elements in this string immediately before
the character referred to by p. All of these versions of
insert require that p is a valid iterator on this string. The
first version inserts a copy of c. The second version inserts n
repetitions of c. The third version
inserts characters in the range [first, last). The first version
returns p.
size_type
length() const;
Return the number of elements contained in this string.
size_type
max_size() const;
Returns the maximum possible size of the string.
size_type
rfind (const basic_string& str, size_type pos = npos) const;
Searches for the last occurrence of the substring specified by
str in this string, starting at position pos. Note that only the
first character of the substring must be <= pos; the
remaining characters may extend beyond pos. If found, the index
of the first character of that matches substring is returned.
If not found, npos is returned. Equality is defined by
traits::eq().
size_type
rfind(const charT* s, size_type pos, size_type n) const;
size_type
rfind(const charT* s, size_type pos = npos) const;
size_type
rfind(charT c, size_type pos = npos) const;
Searches for the last sequence of characters in this string
matching a specified string. The rfind variations return,
respectively:
rfind(basic_string(s,n), pos)
rfind(basic_string(s), pos)
rfind(basic_string(1, c), pos)
basic_string&
replace(size_type pos, size_type n1, const basic_string& s);
basic_string&
replace(size_type pos1, size_type n1, const basic_string& str,
size_type pos2, size_type n2);
basic_string&
replace(size_type pos, size_type n1, const charT* s,
size_type n2);
basic_string&
replace(size_type pos, size_type n1, const charT* s);
basic_string&
replace(size_type pos, size_type n1, size_type n2, charT c);
The replace function replaces selected elements of this string
with an alternate set of elements. All of these versions insert
the new elements in place of n1 elements in this string, starting
at position pos. They each throw an out_of_range
exception if pos1 > size()and a length_error exception if the
resulting string size exceeds max_size().
The second version replaces elements of the original string with
n2 characters from string s starting at position pos2. It will
throw the out_of_range exception if pos2 > s.size(). The third
variation of the function replaces elements in the original string
with n2 elements from the array pointed to by s. The fourth
version replaces elements in the string with elements from the
array pointed to by s, up to, but not including, a
traits::eos() character. The fifth replaces n elements with n2
repetitions of character c.
basic_string&
replace(iterator i1, iterator i2,
const basic_string& str);
basic_string&
replace(iterator i1, iterator i2, const charT* s,
size_type n);
basic_string&
replace(iterator i1, iterator i2, const charT* s);
basic_string&
replace(iterator i1, iterator i2, size_type n,
charT c);
template<class InputIterator>
basic_string&
replace(iterator i1, iterator i2,
InputIterator j1, InputIterator j2);
Replace selected elements of this string with an alternative set
of elements. All of these versions of replace require
iterators i1 and i2 to be valid iterators on this string. The
elements specified by the range [i1,i2) are replaced by
the new elements.
The first version shown here replaces with all members in
str. The second version starts at position i1, and replaces
the next n characters with n characters of the array
pointed to by s. The third variation replaces string
elements with elements from the array pointed to by s up
to, but not including, a traits::eos() character. The fourth
version replaces string elements with n repetitions of c.
The last variation shown here replaces string elements with
the members specified in the range [j1, j2).
void
reserve(size_type res_arg);
Assures that the storage capacity is at least res_arg.
void
resize(size_type n, charT c);
void
resize(size_type n);
Changes the capacity of this string to n. If the new capacity is
smaller than the current size of the string, then it is
truncated. If the capacity is larger, then the string is padded
with c characters. The latter resize member pads the string
with default characters specified by traits::eos().
size type
size() const;
Return the number of elements contained in this string.
basic_string
substr(size_type pos = 0, size_type n = npos) const;
Returns a string composed of copies of the lesser of n and size()
characters in this string starting at index pos. Throws an
out_of_range exception if pos <= size().
void
swap(basic_string& s);
Swaps the contents of this string with the contents of s.
NON-MEMBER OPERATORS
template<class charT, class traits, class Allocator>
basic_string
operator+(const basic_string& lhs, const basic_string& rhs);
Returns a string of length lhs.size() + rhs.size(), where
the first lhs.size() elements are copies of the elements
of lhs, and the next rhs.size() elements are copies of
the elements of rhs.
template<class charT, class traits, class Allocator>
basic_string
operator+(const charT* lhs, const basic_string& rhs);
template<class charT, class traits, class Allocator>
basic_string
operator+(charT lhs, const basic_string& rhs);
template<class charT, class traits, class Allocator>
basic_string
operator+(const basic_string& lhs, const charT* rhs);
template<class charT, class traits, class Allocator>
basic_string
operator+(const basic_string& lhs, charT rhs);
Returns a string that represents the concatenation of two
string-like
entities. These functions return, respectively:
basic_string(lhs) + rhs
basic_string(1, lhs) + rhs
lhs + basic_string(rhs)
lhs + basic_string(1, rhs)
template<class charT, class traits, class Allocator>
bool
operator==(const basic_string& lhs, const basic_string& rhs);
Returns a boolean value of true if lhs and rhs are equal,
and false if they are not. Equality is defined by the
compare() member function.
template<class charT, class traits, class Allocator>
bool
operator==(const charT* lhs, const basic_string& rhs);
template<class charT, class traits, class Allocator>
bool
operator==(const basic_string& lhs, const charT* rhs);
Returns a boolean value indicating whether lhs and rhs are equal.
Equality is defined by the compare() member function. These
functions return, respectively:
basic_string(lhs) == rhs
lhs == basic_string(rhs)
template<class charT, class traits, class Allocator>
bool
operator!=(const basic_string& lhs,
const basic_string& rhs);
Returns a boolean value representing the inequality of lhs
and rhs. Inequality is defined by the compare()
member function.
template<class charT, class traits, class Allocator>
bool
operator!=(const charT* lhs, const basic_string& rhs);
template<class charT, class traits, class Allocator>
bool
operator!=(const basic_string& lhs, const charT* rhs);
Returns a boolean value representing the inequality of lhs
and rhs. Inequality is defined by the compare()
member function. The functions return, respectively:
basic_string(lhs) != rhs
lhs != basic_string(rhs)
template<class charT, class traits, class Allocator>
bool
operator<(const basic_string& lhs, const basic_string& rhs);
Returns a boolean value representing the lexicographical
less-than relationship of lhs and rhs. Less-than is defined
by the compare() member.
template<class charT, class traits, class Allocator>
bool
operator<(const charT* lhs, const basic_string& rhs);
template<class charT, class traits, class Allocator>
bool
operator<(const basic_string& lhs, const charT* rhs);
Returns a boolean value representing the lexicographical
less-than relationship of lhs and rhs. Less-than is defined
by the compare() member
function. These functions return, respectively:
basic_string(lhs) < rhs
lhs < basic_string(rhs)
template<class charT, class traits, class Allocator>
bool
operator>(const basic_string& lhs, const basic_string& rhs);
Returns a boolean value representing the lexicographical
greater-than relationship of lhs and rhs. Greater-than
is defined by the compare() member function.
template<class charT, class traits, class Allocator>
bool
operator>(const charT* lhs, const basic_string& rhs);
template<class charT, class traits, class Allocator>
bool
operator>(const basic_string& lhs, const charT* rhs);
Returns a boolean value representing the lexicographical
greater-than relationship of lhs and rhs. Greater-than
is defined by the compare() member. The functions return,
respectively:
basic_string(lhs) > rhs
lhs > basic_string(rhs)
template<class charT, class traits, class Allocator>
bool
operator<=(const basic_string& lhs,
const basic_string& rhs);
Returns a boolean value representing the
lexicographical
less-than-or-equal relationship of lhs and rhs.
Less-than-or-equal is defined by the compare()
member function.
template<class charT, class traits, class Allocator>
bool
operator<=(const charT* lhs, const basic_string& rhs);
template<class charT, class traits, class Allocator>
bool
operator<=(const basic_string& lhs, const charT* rhs);
Returns a boolean value representing the lexicographical
less-than-or-equal relationship of lhs and rhs.
Less-than-or-equal is defined by the compare() member function.
These functions return, respectively:
basic_string(lhs) <= rhs
lhs <= basic_string(rhs)
template<class charT, class traits, class Allocator>
bool
operator>=(const basic_string& lhs, const basic_string& rhs);
Returns a boolean value representing the lexicographical
greater-than-or-equal relationship of lhs and rhs.
Greater-than-or-equal is defined by the compare() member
function.
template<class charT, class traits, class Allocator>
bool
operator>=(const charT* lhs, const basic_string& rhs);
template<class charT, class traits, class Allocator>
bool
operator>=(const basic_string& lhs, const charT* rhs);
Returns a boolean value representing the lexicographical
greater-than-or-equal relationship of lhs and rhs.
Greater-than-or-equal is defined
by the compare() member. The functions return, respectively:
basic_string(lhs) >= rhs
lhs >= basic_string(rhs)
template <class charT, class traits, class Allocator>
void swap(basic_string<charT,traits,Allocator>& a,
basic_string<charT,traits,Allocator>& b);
Swaps the contents of a and b by calling a's swap function on
b.
template<class charT, class traits, class Allocator>
istream&
operator>>(istream& is, basic_string& str);
Reads str from is using traits::char_in until a
traits::is_del() element is read. All elements read,
except the delimiter, are placed in
str. After the read, the function returns is.
template<class charT, class traits, class Allocator>
ostream&
operator<<(ostream& os, const basic_string& str);
Writes all elements of str to os in order from first to last, using
traits::char_out(). After the write, the function returns os.
NON-MEMBER FUNCTION
template <class Stream, class charT, class traits,
class Allocator>
Stream&
getline(Stream& is, basic_string& str, charT delim);
An unformatted input function that extracts characters from is
into str until npos - 1 characters are read, the end of
the input sequence is reached, or the character read is
delim. The characters are read using traits::char_in().
EXAMPLE
//
// string.cpp
//
#include<string>
#include <iostream.h>
int main()
{
string test;
//Type in a string over five characters long
while(test.empty() || test.size() <= 5)
{
cout << "Type a string between 5 and 100 characters long. "
<< endl;
cin >> test;
}
//Test operator[] access
cout << "Changing the third character from " << test[2] <<
" to * " << endl;
test[2] = '*';
cout << "now its: " << test << endl << endl;
//Try the insertion member function
cout << "Identifying the middle: ";
test.insert(test.size() / 2, "(the middle is here!)");
cout << test << endl << endl;
//Try replacement
cout << "I didn't like the word 'middle',so instead,I'll say:"
<< endl;
test.replace(test.find("middle",0), 6, "center");
cout << test << endl;
return 0;
}
Output :
Type a string between 5 and 100 characters long.
roguewave
Changing the third character from g to *
now its: ro*uewave
Identifying the middle: ro*u(the middle is here!)ewave
I didn't like the word 'middle', so instead, I'll say:
ro*u(the center is here!)ewave
SEE ALSO
Allocators, string, wstring
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
Additional Information (explode) :
|
|