Appending to boost::filesystem::path

Question

I have a certain boost::filesystem::path in hand and I'd like to append a string (or path) to it.

boost::filesystem::path p("c:\\dir");
p.append(".foo"); // should result in p pointing to c:\dir.foo

The only overload boost::filesystem::path has of append wants two InputIterators.

My solution so far is to do the following:

boost::filesystem::path p2(std::string(p.string()).append(".foo"));

Am I missing something?

Answer 1

If it's really just the file name extension you want to change then you are probably better off writing:

p.replace_extension(".foo");

for most other file path operations you can use the operators /= and / allowing to concatenate parts of a name. For instance

boost::filesystem::path p("c:\\dir");
p /= "subdir";

will refer to c:\dir\subdir.

Answer 2

#include <iostream>
#include <string>
#include <boost/filesystem.hpp>


int main() {
  boost::filesystem::path p (__FILE__);

  std::string new_filename = p.leaf() + ".foo";
  p.remove_leaf() /= new_filename;
  std::cout << p << '\n';

  return 0;
}

Tested with 1.37, but leaf and remove_leaf are also documented in 1.35. You'll need to test whether the last component of p is a filename first, if it might not be.