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wcsxfrm

From cppreference.com
< c‎ | string‎ | wide

Defined in header <wchar.h>
size_t wcsxfrm( const wchar_t* dest, const wchar_t* src, size_t count );
(until C99)
(since C95)
size_t wcsxfrm( const wchar_t* restrict dest, const wchar_t* restrict src, size_t count );
(since C99)

Transforms the null-terminated wide string pointed to by src into the implementation-defined form such that comparing two transformed strings with wcscmp gives the same result as comparing the original strings with wcscoll, in the current C locale.

The first count characters of the transformed string are written to destination, including the terminating null character, and the length of the full transformed string is returned, excluding the terminating null character.

If count is 0, then dest is allowed to be a null pointer.

Contents

[edit] Notes

The correct length of the buffer that can receive the entire transformed string is 1+wcsxfrm(NULL, src, 0)

[edit] Parameters

dest - pointer to the first element of a wide null-terminated string to write the transformed string to
src - pointer to the null-terminated wide character string to transform
count - maximum number of characters to output

[edit] Return value

The length of the transformed wide string, not including the terminating null-character.

[edit] Example

#include <stdio.h>
#include <wchar.h>
#include <locale.h>
 
int main(void)
{
    setlocale(LC_ALL, "sv_SE.utf8");
 
    const wchar_t *in1 = L"\u00e5r";
    wchar_t out1[1+wcsxfrm(NULL, in1, 0)];
    wcsxfrm(out1, in1, sizeof out1/sizeof *out1);
 
    const wchar_t *in2 = L"\u00e4ngel";
    wchar_t out2[1+wcsxfrm(NULL, in2, 0)];
    wcsxfrm(out2, in2, sizeof out2/sizeof *out2);
 
    printf("In the Swedish locale: ");
    if(wcscmp(out1, out2) < 0)
         printf("%ls before %ls\n", in1, in2);
    else
         printf("%ls before %ls\n", in2, in1);
 
    printf("In lexicographical comparison: ");
    if(wcscmp(in1, in2) < 0)
         printf("%ls before %ls\n", in1, in2);
    else
         printf("%ls before %ls\n", in2, in1);
}

Output:

In the Swedish locale: år before ängel
In lexicographical comparison: ängel before år

[edit] See also

compares two strings in accordance to the current locale
(function) [edit]
compares two wide strings in accordance to the current locale
(function) [edit]
(C95)
compares two wide strings
(function) [edit]
transform a string so that strcmp would produce the same result as strcoll
(function) [edit]
C++ documentation for wcsxfrm