Re: [boost] Re: more flexible lexical_cast

From: Matthias Troyer (troyer_at_[hidden])
Date: 2002-08-22 16:36:28

On Thursday, August 22, 2002, at 12:40  PM, Alberto Barbati wrote:

> Terje Slettebø wrote:
>
>> Would it really be an advantage to use "t=interpreter.str()" instead 
>> of "t
>> << interpreter"? Performance, perhaps. Have you done any measurements, 
>> or
>> something like that, to show that this specialisation is worthwile?
>
> It's not just a matter of performances here. "t=interpreter.str()" and
> "interpreter >> t" do two completely different things. In particular, 
> the latter stops at the first whitespace while the former does not. In 
> fact, one thing that striked me at first when studying lexical_cast is 
> that with the current implementation, the expression:
>
> boost::lexical_cast<std::string>(std::string("hello, world"))
>
> not only does not return the string "hello, world" but throws an 
> exception because of the space. It's very counter-intuitive, IMHO.

I agree with Alberto and also do not like these feature. I have patched 
myself
a separate version which returns "hello, world" in this case, since I 
need
this behavior in my applications. Is there any reason for not 
specializing
lexical_cast for a target of std::string?

Matthias