Converting CLI array to std::string without for-cycle

Question

I want to convert array<unsigned char>^ to std::string. Is it possible to do the conversion without iterating over the array and assigning each character in string?

This is my "best" solution (and I don't like the assigning in for-cycle):

std::string CliArray2String(array<unsigned char>^ aSource)
{
    std::string strResult("");
    if (aSource != nullptr)
    {
        int iLength = aSource->GetLength(0);
        strResult.reserve(iLength + 1);
        for (int i = 0; i < iLength; i++)
            strResult[i] = aSource[i];
    }
    return strResult;
}

Thanks for your opinions.

Unrelated to your question, but you declare strResult as a narrow-character string, but the return type is a wide-character string. — Some programmer dude
– Some programmer dude, Commented Aug 18, 2014 at 8:45
This is a non-trivial and lossy conversion, you cannot cram a Unicode codepoint into a byte. That for-loop is going to be somewhere, doesn't much matter where. You can pretend it doesn't exist with Marshal::StringToHGlobalAnsi() for example. — Hans Passant
– Hans Passant, Commented Aug 20, 2014 at 13:02

Yochai Timmer · Accepted Answer · 2014-08-20 12:59:24Z

1

You can use the string range constructor, and pin the managed array.

pin_ptr<unsigned char> p = &aSource[0];
unsigned char *unmanagedP = p;
std::string str(unmanagedP , unmanagedP + aSource->GetLength(0));

or the sequence constructor:

std::string str(unmanagedP , aSource->GetLength(0));

answered Aug 20, 2014 at 12:59

Yochai Timmer

49.6k25 gold badges154 silver badges191 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Bob C Over a year ago

That still iterates, but at least it doesn't look like it is. The answer to the original question is, of course, "no."

Collectives™ on Stack Overflow

Converting CLI array to std::string without for-cycle

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related