Optional File Creation for boost::interprocess::file_lock

[Peter LaDow <petela@…>]

An optional overload (default second argument?) for the constructor to create and open the file to use for the file_lock would be very useful.

Currently, when creating a file lock, I typically do something like:

std::ofstream tmpf(/path/to/lock/file);  tmpf.close();
boost::interprocess:file_lock f_lock(/path/to/lock/file);

Say I have a class, such as:

class Foo
{
  public:
    Foo();

  private:
    boost::interprocess::file_lock f_lock;
};

I have to do the following in the constructor:

Foo::Foo()
{
  std::ofstream tmpf(/path/to/lock/file);  tmpf.close();
  boost::interprocess:file_lock tmp_lock(/path/to/lock/file);  

  f_lock.swap(tmp_lock);
}

This is cumbersome and limits usefulness in initializer lists. Tweaking the constructor to something like:

file_lock::file_lock(const char *path, bool create = false);

Would allow a constructor to do the following:

Foo::Foo()
  : f_lock(/path/to/file/lock, true)
{
}