[boost] RFC: parm_string

From: Kevin Atkinson (kevin_at_[hidden])
Date: 2004-02-06 16:39:53

Here is a very simple, but extremely useful, class I would like to submit 
for inclusion for boost: parm_string.

parm_string is a special string class that is designed to be used as
a parameter for a function that is expecting a string.  It will allow
either a "const char *" or "string" class to be passed in.  It will
automatically convert to a "const char *".  The string can also be
accesses via the "str" method.  Usage example:

void foo(parm_string s1, parm_string s2) {
  const char *  str0 = s1;
  size_t sz = s2.size()
  if (s1 == s2 || s2 == "bar") {
    ...
  }
}
..
string s1 = "...";
foo(s1);
const char * s2 = "...";
foo(s2);

By using parm_string instead on "const char *" one avoids the need
to have to use the c_str() member every time a string is passed
into a function.  It is also more effect than just using "const
char *" as the length information is passed in if it is known.
It is also more efferent than just using "const string &" as that
will involve creating an unnecessary temporary when a non string
object is used.

In my experience most functions that require a string as a parameter
really only need the value of the string and possibly its length.
They don't need the functionally of the full "string" class.

Attached is parm_string.hpp and a simpile program parm_string.cpp

I use a variant of this class heavily in my programs I find it extremely 
useful.

-- 
http://kevin.atkinson.dhs.org