std::wcschr

#include <iostream>
#include <cwchar>
#include <locale>
 
int main()
{
    wchar_t arr[] = L"招き猫 кошка";
    const wchar_t* cat = std::wcschr(arr, L'猫');
    const wchar_t* dog = std::wcschr(arr, L'犬');
 
    std::cout.imbue(std::locale("en_US.utf8"));
 
    if(cat)
        std::cout << "The character 猫 found at position " << cat - arr << '\n';
    else
        std::cout << "The character 猫 not found\n";
 
    if(dog)
        std::cout << "The character 犬 found at position " << dog - arr << '\n';
    else
        std::cout << "The character 犬 not found\n";
}