Convert `const unsigned char []' to `std::string'

[Russell]

What is the best way to convert an `const unsigned char []' to `std::string'?

example:

const unsigned char cbuffer[]={0x61,0x62,0x63,0x0};
std::string sbuffer=cbuffer; // error

[cboard_member]

Hmm I tried it myself in the hope I could help you. I tried using const_cast, static_cast and reinterpret_cast (in that order) with no avail.

I'd like to know how to do this too

Here's how I tried:

#include <string> 
 
int main()
{
	const unsigned char[] cbuffer = { 0x61, 0x62, 0x63, 0x0 };
	std::string sbuffer;
 
	sbuffer = const_cast<std::string> (cbuffer);
	return 0;
}

[Antigloss]

the only way i can think out is to assign cbuffer to a char array, and then use the char array to initialize the string

[cboard_member]

std::string sbuffer (cbuffer);

??

[Russell]

Error:

:!make  2>&1| tee /tmp/v748926/2
g++ -O3 -Wall -pedantic -ansi -c main.cpp
main.cpp: In function `int main()':
main.cpp:9: error: conversion from `const unsigned char[4]'
to non-scalar type `std::basic_string<char, std::char_traits<char>,
std::allocator<char> >' requested
*** Error code 1

// Edited formatting

[dra]

stringstream?

[cboard_member]

Here's a sample function using a stringstream:

#include <sstream>
 
int itos (int i)
{
 stringstream s; 
 s << i;
 return s.str ();
}

It (should) convert an integer to a string, I just typed it off the top of my head, so it probably has a buggy or two.

[hk_mp5kpdw]

const unsigned char cbuffer[]={0x61,0x62,0x63,0x0};
std::string sbuffer=reinterpret_cast<const char*>(cbuffer);

[dra]

#include <iostream>
#include <string>
#include <sstream>

using namespace std;

int main(){
           
         stringstream s;
         char array[] = { 'a', 'b', 'c' };

         s << array;

         string d = s.str();

         cout << d;

    }

Hope this helps.

@ahluka, that looks like it came from Bjarne Stroustrup's FAQ http://www.research.att.com/~bs/bs_f...#int-to-string

lol just kidding.

[cboard_member]

Yeah I know I was just saving him the trouble of looking... Actually I lied about the typing off the top of my head bit, I copied and pasted

[Russell]

const unsigned char cbuffer[]={0x61,0x62,0x63,0x0};
std::string sbuffer=reinterpret_cast<const char*>(cbuffer);

It's important to note that the cast must remain unsigned, otherwise it'll overflow the characters. However, having the cast, as above, unsigned results in an error.

[Russell]

stringstream?

Since cbuffer is a byte array (i.e. it'll containt null characters), stringstream cannot be used, as a null character terminates the stream.

[Russell]

Thanks for your input, all. It is a tricky one (at least for me).

[Codeplug]

Why do you want to use a std::string?
What's wrong with a vector<unsigned char> or basic_string<unsigned char>?

gg

[Russell]

I'll look into those. Thanks.