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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 = "...";
const char * 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


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