boost :: shared_array <char> 到std :: string

Question

What is the best way to convert a boost::shared_array<char> to a std::string ? The following snippet works but it does not look very elegant.

boost::shared_array<char> boostString = DatabaseFileName.GetCString(CZString::eAscii);
std::string stdString;
for(size_t i = 0; boostString[i] != 0; i++)
{
    stdString.append(1, boostString[i]);    
}

Answer 1

Boost shared array uses new[] to allocate its data, which means it's all contiguous in memory. That means you can get a pointer to the first element as a C-style string, from which you can create a std::string instance.

This of course requires the data to either have a terminator, or for you to know the length of the "string".

Answer 2

Checkout following code. This will give you clear idea:

#include <iostream>
#include <string>
#include <boost\shared_array.hpp>

void main()
{   
    char *ptr = "mystring" ;
    boost::shared_array<char> myIntArray(new char[strlen(ptr) + 1]);
    strncpy(myIntArray.get(), ptr, strlen(ptr) + 1);
    std::string str(myIntArray.get());
    std::cout << str << std::endl;

    system("pause");
}

Answer 3

If you don't want to futz around with strncpy and worrying of the boost::shared_array<char> is null-terminated, you can write (assuming boostString and stdString from the original example:

std::copy(boostString.begin(), boostString.end(),
    std::back_inserter<std::string>(stdString));

Answer 4

According to "Some Programmer dude"'s answer I coded the solution. Please notice that the boostString string is zero-terminated.

boost::shared_array<char> boostString = str.GetCString(CZString::eAscii);
std::string stdStr(boostString.get());