byte array (vector)

I have a byte array (vector <char> and I want to copy each byte to string):

The code:

Code:

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using namespaces std;
vector <char> v;
v.resize(20);
//..fill the vector..

// now copy
string str;
copy(v.begin(), v.end(), str.begin());

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The program crashes at the copy line.. What am I doing wrong?

something's probably wrong in the "fill the vector" section of your code. It should work

Regardless:

Code:

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using namespaces std;

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Remove that 's'

Code:

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int main( void )
{
        std::vector <char> v;

        for ( int i='a'; i<'n'; i++ )
                v.push_back( i );

        std::string str;
        str.insert( str.begin(), v.begin(), v.end() );

        std::cout<< '\n' << str;

        return 0;

}

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Or... much easier, you can build the string from the vector using one of the constructor overloads.

Code:

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string str(v.begin(), v.end());

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Quote:

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Originally Posted by Mario F.

Or... much easier, you can build the string from the vector using one of the constructor overloads.

Code:

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string str(v.begin(), v.end());

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Nice!! I didn't know that!! Shame it's not (yet) possible to do it the other way around :/

Code:

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string str = "aaaaaaaaaa";
vector<char> v(str.begin(), str.end());

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;)

FWIW, with a slight modification the original copy function could have been used as well.

Code:

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// now copy
string str;
copy(v.begin(), v.end(), inserter(str,str.end()) );

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Yes. I was actually trying to understand why it wasn't working and experienced a situation where the copy does apparently nothing.

I'm not familiar with that function but I guess it returns an insert iterator, correct?
Cppreference makes no mention to the fact the last argument needs to be one, it seems.