#include <iomanip>
#include <iostream>

#include <boost/filesystem.hpp>
#include <boost/process.hpp>

void print_bytes(const std::string& s)
{
    for (auto ch : s)
    {
        std::cout << ch << "  ";
    }
    std::cout << "size() == " << s.size() << "\n";
    std::cout << std::hex;
    for (auto ch : s)
    {
        std::cout << std::setw(2) << (int)ch << " ";
    }
    std::cout << "\n\n";
    std::cout << std::dec;
}

int main()
{
    boost::process::native_environment ne;

    std::string with_getenv = std::getenv("WINDIR");
    std::cout << "With getenv:\n";
    print_bytes(with_getenv);

    std::cout << "With boost::process::native_environment:\n";
    std::string with_native_environment = ne.get("WINDIR");
    print_bytes(with_native_environment);

    // Real-life example
    boost::filesystem::path windir = with_native_environment;
    auto invalidPath = windir / "SomeNotExistingSubdir";

    std::cout << std::boolalpha;

    std::cout << "boost::process::native_environment-based path:\n";
    print_bytes(windir.string());
    // This path still works correct due to c-style internals
    std::cout << windir << " exists: " << boost::filesystem::exists(windir) << "\n\n";

    std::cout << "After joining:\n";
    print_bytes(invalidPath.string());
    // This path is treated as windir only due to \0
    std::cout << invalidPath << " exists: " << boost::filesystem::exists(invalidPath) << "\n";
    return 0;
}

With getenv:
C  :  \  W  i  n  d  o  w  s  size() == 10
43 3a 5c 57 69 6e 64 6f 77 73

With boost::process::native_environment:
C  :  \  W  i  n  d  o  w  s     size() == 11
43 3a 5c 57 69 6e 64 6f 77 73  0

boost::process::native_environment-based path:
C  :  \  W  i  n  d  o  w  s     size() == 11
43 3a 5c 57 69 6e 64 6f 77 73  0

"C:\Windows " exists: true

After joining:
C  :  \  W  i  n  d  o  w  s     \  S  o  m  e  N  o  t  E  x  i  s  t  i  n  g  S  u  b  d  i  r  size() == 33
43 3a 5c 57 69 6e 64 6f 77 73  0 5c 53 6f 6d 65 4e 6f 74 45 78 69 73 74 69 6e 67 53 75 62 64 69 72

"C:\Windows \SomeNotExistingSubdir" exists: true