Re: [boost] Heads up - string_ref landing

Subject: Re: [boost] Heads up - string_ref landing
From: Beman Dawes (bdawes_at_[hidden])
Date: 2012-11-15 22:13:28

On Thu, Nov 15, 2012 at 3:41 PM, Phil Endecott
<spam_from_boost_dev_at_[hidden]> wrote:
> Marshall Clow wrote:
>>
>> I'm about to check in some new functionality into the string_algo library;
>> an implementation of string_ref.
>>
>> A string_ref is a non-owning reference to a string. It is implemented as a
>> {pointer, length} pair, and is exceedingly useful
>> when parsing, and manipulating strings in "read-only" ways.
>
>
> I did something like this once.  I called mine const_string_facade - I also
> had a mutable version - and it was a template that took an iterator pair.
> This lets you adapt something like a vector<char> into a string.

basic_string_ref doesn't template its member functions with container
or iterator parameter types, so it can't do something like adapting a
vector<char> or list<char> into a string.  A range-like type
(basic_string_range?) would be better for that, handles iterator types
generically, and also would be able to handle NTCTS more efficiently.
OTOH, operations that require random access iterators can use
basic_string_ref directly, but can't use a basic_string_range type,
which typically only requires input iterators.

> BUT, I think my feeling is that this is actually taking us in the wrong
> direction: my current coding style tries to avoid the "special" features of
> std::string and prefers the things that are common to other containers, and
> std::algorithms.

Yeah, I have some similar misgivings. I'd be happier if
basic_string_ref and basic_string_range were part of the same proposal
so users got in the habit of choosing the approach that is best for
their need.

--Beman