Re: [boost] Boost review of the Convert library is ongoing

Subject: Re: [boost] Boost review of the Convert library is ongoing
From: Arpit (arpitmittal108_at_[hidden])
Date: 2014-05-23 08:05:05

alex <alexhighviz_at_[hidden]> wrote:

>>>>
>>> The benefit is that it defers initialization and thus passes that
>>> responsibility from the generic function to the specific converters.
>>>
>> Let's try staying with mainstream usage examples meaningful for the
>majority of users. I'll
>>unlikely be persuaded by an esoteric academic (even a real but
>>corner-case) example that will have negative impact on the real users.
>>Thoughts?..
>
>The convert contract you are proposing is quite abstract, so I think
>academic arguments are relevant. But your question can be translated to: are
>there real examples of classes that are expensive to construct but cheap to
>move? Moreover, these classes need to be potential candidates for being
>converted to.
>
>The example you have been using is encryption. Consider the following class
>for an encrypted password:
>
>struct encrypted_password
>{
>  encrypted_password(const std::string& password) 
>  {
>    // connect to random number device
>    // do all kinds of arithmetic to encrypt
>    // send email to NSA
>    // m_encrypted will have a minimum size of 128.
>  }
>  encrypted_password (password_encryption&& rhs) : m_encrypted
>(std::move(rhs.m_encrypted))
>  {  }
>
>  bool check_password(const std::string& password){}
>
>private:
>  std::string m_encrypted;
>};
>
>Now I can write a converter:
>
>struct password_converter
>{
>  void operator()(const std::string& in,
>boost::optional<password_encryption>& out)
>  {
>    try { 
>       out  = password_encryption(in);
>    } catch(...) {
>       out = boost::none; 
>    }
>  }
>};
>
>
>
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