Re: [boost] Convert library -- Andrzej's review

20 May 2014

      On 05/18/2014 11:45 PM, Vladimir Batov wrote:
...
Vladimir Batov  writes:
...
Andrzej Krzemienski  writes:
...
I personally do not like this trick to force me to type this "from" in
"convert<int>::from".
I just had another look and there seems no value anymore in potential
specializations on TypeIn, TypeOut. It's because all the "smartness" and
type-handling has been moved to converters. So, *there seems*, the "from"
can be dropped. That is,
int v = boost::convert<int>(str, cnv).value();
instead
int v = boost::convert<int>::from(str, cnv).value();
and
std::transform(
    strings.begin(),
    strings.end(),
    std::back_inserter(integers),
    convert(ccnv(std::hex)).value_or(-1));
instead
std::transform(
    strings.begin(),
    strings.end(),
    std::back_inserter(integers),
    convert<int>::from<string>(ccnv(std::hex)).value_or(-1));
I am on the fence (the "from" has been with me for some time). Any
strong/weak :-) preferences, any for/against arguments?
Given a few people were not happy with boost::convert::from() interface 
I've added boost::cnv() for now (so that the names do not clash while 
both exist).

     int v = boost::cnv<int>(str, cnv).value();

does look cleaner and somewhat similar to lexical_cast deployment (for 
better or worse). However, I feel similarly confused about

     boost::cnv(cnv).value_or(-1);

as I always felt about lexical_cast when I had to specify both types

     boost::lexical_cast("char string");

compared to more explicit

     convert<int>::from<string>(cnv).value_or(-1);

I am easy about both ways and will go with whatever the majority settles 
on. Any feelings/preferences/arguments for one or the other?