Replace strcpy

Question

I have the following code:

void test_func(const char(*str)[4])
{
    std::cout << *str << std::endl;
}

caller code:

std::string s{"abc"};
char c[4];
strcpy_s(c, s.c_str());
test_func(&c);

It is possible to replace char[4] with modern std::vector<char> ? If it is, how can I do that ?

I have tried a silly code:

std::vector<char> chars(s.cbegin(), s.cend());
test_func(&chars[0]);

Of course, didn't work it.

Answer 1

It's not safe but you could call the library function using a properly sized string s -

test_func(reinterpret_cast<const char(*)[4]>(s.c_str()));