[Boost-users] more on lexical_cast bool

From: Paul Moore (paul.moore_at_[hidden])
Date: 2007-04-19 18:07:05

I hit the same problem that was addressed earlier in these lists
 
The proposed solution was to juggle around with the internal streams.
 
The problem with this (it seems to me) is that is leaking the
implementation into the consumers face.
We all know that lexical_cast is implemented using streaming in and out
and thats what makes it pretty lightweight (in terms of the amount of
code used) but thats no reason to leak the details out.
 
The other problem is that lexical_cast is really slow; again becuase it
uses such a general purpose mechanism.
 
Its seems to me that the class needs specializing
 
* to bool should accept true and false in any case, or 0 or any non-zero
int and perhaps yes and no (this is the programmers expectation)
* ints should use atoi and fixed size snprintfs
* Etc...
 
the general >> << mechanism is used if there is no specialization
 
This makes it fast(er) and makes it opaque