string_char_traits

A traits class providing types and operations to the basic_string container.

Contents

• Summary
• Synopsis
• Description
• Interface
• Type
• Operations
• See Also

#include <string>

template <class charT> struct string_char_traits
struct string_char_traits<char>; .
struct string_char_traits<wchar_t>;

The string_char_traits struct provides elementary operations to instantiations of basic_string. As with all traits classes, string_char_traits is used to specialize the behavior of a template. In this case, the traits class provides functions based on character type to the basic_string template.

Specializations of string_char_traits are provided for char and wchar_t. These are used to define, respectively, string and wstring.

template <class charT> struct string_char_traits .
{  
typedef charT                    char_type;
static void assign (char_type&, const char_type&); .
static char_type* assign (char_type*, size_t, const char_type&);
static bool eq (const char_type&, const char_type&); .
static bool ne (const char_type&, const char_type&); .
static bool lt (const char_type&, const char_type&); .
static char_type eos ();  .
static int compare (const char_type*, const char_type*, size_t);
.
static size_t length (const char_type * s); .
static char_type* copy (char_type*,  const char_type*, size_t);
.
static char_type* move (char_type*,  const char_type*, size_t);
.
static const char_type*  .
find (const char_type*, int, const char_type&);
};

char_type

The basic character type. Same as the template parameter.

static 
void assign (char_type& c1, const char_type& c2) 

Assign one character value to another. The value of c2 is assigned to c1.

static 
char_type* assign (char_type* s, size_t n, const char_type& a)

Assign one character value to n elements of a character array. The value of a is assigned to n elements of s.

static 
bool eq (const char_type& c1, const char_type& c2)

Return true if c1 equals c2.

static 
bool ne (const char_type& c1, const char_type& c2)

Return true if c1 does not equal c2.

static 
bool lt (const char_type& c1, const char_type& c2)

Return true if c1 is less than c2.

static 
char_type eos ()

Return the end of string value for the the character type. Typically char_type().

static 
int compare (const char_type* s1, const char_type* s2, 
             size_t n)

Compare n values from s1 with n values from s2. Return 1 if s1 is greater than s2, -1 if s1 is less than s2, or 0 if they are equal.

static 
size_t length (const char_type * s)

Return the length of the null terminated character array s. The eos terminator is not counted.

static 
char_type* copy (char_type* s1, const char_type* s2, size_t n)

Copy n values from s1 to s2. The ranges of (s1,s1+n) and (s2,s2+n) may not overlap.

static
char_type* move (char_type* s1, const char_type* s2, size_t n)

Move n values from s1 to s2. The ranges of (s1,s1+n) and (s2,s2+n) may overlap.

static 
const char_type* find (const char_type* s, int n, 
       const char_type& a)

Look for the value of a in s. Only n elements of s are examined. Returns a pointer to the matched element if one is found. Otherwise returns s + n.

basic_string