Re: [Boost-users] Boost utility to get const value_type for const std containers?

Subject: Re: [Boost-users] Boost utility to get const value_type for const std containers?
From: Marshall Clow (mclow.lists_at_[hidden])
Date: 2010-07-05 18:02:53

On Jul 5, 2010, at 2:50 PM, Mostafa wrote:

> On Mon, 05 Jul 2010 14:35:58 -0700, Marshall Clow <mclow.lists_at_[hidden]> wrote:
> 
>> On Jul 5, 2010, at 2:10 PM, Mostafa wrote:
>> 
>>> Hi all,
>>> 
>>> Is there a boost utility that will return the "correct" value_type for std containers? i.e., for:
>>> 
>>> typedef std::vector<char> const CharVector;
>>> 
>>> is there SomeBoostUtility<CharVector>::Type == char const ?
>> 
>> I don't know of one, but this should work:
>> 
>> template <class Container>
>> bool equal_to_string ( const Container &c, const typename Container::value_type *pFirst ) {
>> 	return std::equal ( c.begin (), c.end (), pFirst );
>> }
> 
> Thanks, I was actually looking for something that will return either a const or non-const qualified value_type for the complimentary qualified container type. Something like this:
> 
> template <typename T>
> struct StdContainerValue
> {
>    typedef typename T::value_type Type;
> };
> 
> template <typename T>
> struct StdContainerValue<T const>
> {
>    typedef typename T::value_type const Type;
> };

Sorry --  I completely misread your posting.

-- Marshall