How do I output an unsigned char* to file without reinterpret_cast

Question

I have an unsigned char* filled with characters not just ASCII for example: `

¤ÝkGòd–ùë$}ôKÿUãšj@Äö5ÕnE„_–Ċ畧-ö—RS^HÌVÄ¥U`  . 

If I reinterpret_cast, I'll lose characters if I'm not mistaken because they're not all ASCII. I've searched everywhere but all the solutions require some sort of casting or conversion that will alter the data. Here's what I have, which doesn't work.

unsigned char* cipherText = cipher->encrypt(stringTest);
string cipherString(reinterpret_cast<char*>(cipherText));  //<-- At this point data changes in debugger
outputfile.open(outfile);       
outputfile.close();             

Answer 1

You're not calling the string constructor you should be calling. Instead of the one that takes a single char * argument, you should call the one that takes two arguments - a char * and length.

basic_string( const CharT* s,
              size_type count,
              const Allocator& alloc = Allocator() );

To use it in your example

unsigned char* cipherText = cipher->encrypt(stringTest);
size_t cipherTextLength = // retrieve this however the API allows you to
string cipherString(reinterpret_cast<char*>(cipherText), cipherTextLength);

outputfile.open(outfile);       
// assuming outputfile is an ofstream
outputfile << cipherString;
outputfile.close();  

Note that the debugger might still indicate a truncated string depending on how it's interpreting the string's contents. If you open the output file in an editor and inspect the bytes you should see the expected result.

As RemyLebeau mentions in the comments, if you don't need the std::string for any other purpose, you don't even need to create it, just write to the ofstream directly.

outputfile.open(outfile);       
outputfile.write(reinterpret_cast<char*>(cipherText), cipherTextLength);
outputfile.close();