NAME

std::wcsspn - std::wcsspn

Synopsis

Defined in header <cwchar>
size_t wcsspn( const wchar_t* dest, const wchar_t* src );

Returns the length of the maximum initial segment of the wide string pointed to by
dest, that consists of only the characters found in wide string pointed to by src.

Parameters

dest - pointer to the null-terminated wide string to be analyzed
src - pointer to the null-terminated wide string that contains the characters to
search for

Return value

The length of the maximum initial segment that contains only characters from wide
string pointed to by src

Example

// Run this code

#include <cwchar>
#include <iostream>
#include <locale>

int main()
{
wchar_t dest[] = L"白猫 黑狗 甲虫";
const wchar_t src[] = L" 狗猫 白黑 ";
const std::size_t len = std::wcsspn(dest, src);
dest[len] = L'\0'; // terminates the segment to print it out

std::wcout.imbue(std::locale("en_US.utf8"));
std::wcout << L"The length of maximum initial segment is " << len << L".\n";
std::wcout << L"The segment is \"" << dest << L"\".\n";
}

Possible output:

The length of maximum initial segment is 6.
The segment is "白猫 黑狗 ".

See also

returns the length of the maximum initial segment that consists
wcscspn of only the wide not found in another wide string
(function)
finds the first location of any wide character in one wide string, in
wcspbrk another wide string
(function)