Slides from my ACCU Silicon Valley talk

[biozic]

Le 14/12/10 09:56, Andrei Alexandrescu a écrit :
> On 12/14/10 2:23 AM, Walter Bright wrote:
>> bearophile wrote:
>>> Andrei:
>>>
>>>> D's constrained templates were introduced on 17 June 2008 and they've
>>>> been
>>>> a smashing hit. Virtually all of Phobos uses them, and I'm sure a 
>>>> lot of
>>>> generic client code. They take half a minute to explain and solve a
>>>> difficult problem in a very simple manner.<
>>>
>>> A template with two constrains makes it less handy to add error
>>> messages that
>>> explain why the instantiation has failed:
>>
>> Adding such error messages misses the point of constraints. The idea is
>> that template overloading is based on constraints. Given 3 templates
>> with 3 constraints, overload resolution picks the one with constraints
>> that pass. Giving error messages for the others is wrong.
>>
>> If you want it to produce error messages if the instantiation is wrong,
>> the correct way is to use static asserts within the template body. No
>> additional features serve any purpose.
>
> Yah, I was planning on writing the same response.
>
> Andrei

I have a question about this and some pieces of code in the standard 
library, notably std.algorithm: some of the templated functions use 
template constraints even when no template overloading is taking place. 
Wouldn't some static asserts help print more accurate messages when 
these functions are misused?

Nicolas