#include <chrono>
#include <cstdlib>

#define STR_LEN  10
typedef char fixed_string[STR_LEN+1];

static const char *
gen_str()
{
    static fixed_string s;
    for (size_t i = 0; i < sizeof(fixed_string)-1; ++i) {
        s[i] = rand() % 25 + 65;
    }
    s[sizeof(s)-1] = '\0';
    return s;
}

static std::chrono::time_point<std::chrono::high_resolution_clock>
get_time ()
{
    return std::chrono::high_resolution_clock::now();
}

template<typename T>
std::chrono::microseconds
time_diff (const T& begin, const T& end)
{
    return std::chrono::duration_cast<std::chrono::microseconds>(end - begin);
}