[boost] relative/absolute paths in filesystem library

From: Matthias Troyer (troyer_at_[hidden])
Date: 2002-11-24 14:15:24

I have started using the boost filesystem library in our application 
codes and encountered a problem that could be solved by adding either 
of the three functions

bool is_relative() const;
bool is_absolute() const;
void make_absolute();

to the path class.

Let me motivate this by an example: if the user specifies a relative 
path the file system library automatically prepends it with the result 
of a call to initial_directory(). In parallel programs however, even 
when the file system is shared, the result of a call to  
initial_directory() need not be the same on all nodes of a parallel 
machine. Thus I need to convert all relative paths to absolute ones 
before sending the path to another node.

At the moment I check for this by asking whether the first character is 
a '/', but this works only under  Unix variants but not under Windows. 
Although we do not run our codes under Windows, other users of our 
libraries might and I would thus like to have a portable method, which 
could be implemented through either of the three functions mentioned 
above. Neither of the functions should be more than a single-line 
function.

What do you think about that?

Best regards,

Matthias