How do you construct a std::string with an embedded null?
c++, null, stdstring
Solution
Since C++14
we have been able to create literal `std::string`
#include <iostream>
#include <string>
int main()
{
using namespace std::string_literals;
std::string s = "pl-\0-op"s; // <- Notice the "s" at the end
// This is a std::string literal not
// a C-String literal.
std::cout << s << "\n";
}
Before C++14
The problem is the `std::string` constructor that takes a `const char*` assumes the input is a C-string. C-strings are `\0` terminated and thus parsing stops when it reaches the `\0` character.
To compensate for this, you need to use the constructor that builds the string from a char array (not a C-String). This takes two parameters - a pointer to the array and a length:
std::string x("pq\0rs"); // Two characters because input assumed to be C-String
std::string x("pq\0rs",5); // 5 Characters as the input is now a char array with 5 characters.
Note: C++ `std::string` is NOT `\0`-terminated (as suggested in other posts). However, you can extract a pointer to an internal buffer that contains a C-String with the method `c_str()`.
Also check out Doug T's answer below about using a `vector<char>`.
Also check out RiaD for a C++14 solution.
Problem
If I want to construct a std::string with a line like: ``` std::string my_string("a\0b"); ``` Where i want to have three characters in the resulting string (a, null, b), I only get one. What is the proper syntax?