Copying non null-terminated unsigned char array to std::string

Question

If the array was null-terminated this would be pretty straight forward:

unsigned char u_array[4] = { \'a\', \'s\', \'d\', \'\\0\' };
std::string str         


        

Answer 1

There is a still a problem when the string itself contains a null character and you try to subsequently print the string:

char c_array[4] = { 'a', 's', 'd', 0 };

std::string toto(array,4);
cout << toto << endl;  //outputs a 3 chars and a NULL char

However....

cout << toto.c_str() << endl; //will only print 3 chars.

Its times like these when you just want to ditch cuteness and use bare C.

Answer 2

This should do it:

std::string s(u_array, u_array+sizeof(u_array)/sizeof(u_array[0]));

Answer 3

You can create a character pointer pointing to the first character, and another pointing to one-past-the-last, and construct using those two pointers as iterators. Thus:

std::string str(&u_array[0], &u_array[0] + 4);

Answer 4

std::string has a constructor taking an array of char and a length.

unsigned char u_array[4] = { 'a', 's', 'd', 'f' };
std::string str(reinterpret_cast<char*>(u_array), sizeo(u_array));

Answer 5

Ew, why the cast?

 std::string str(u_array, u_array + sizeof(u_array));

Done.

Answer 6

Well, apparently std::string has a constructor that could be used in this case:

std::string str(reinterpret_cast<char*>(u_array), 4);