Subject: Re: [boost] [non Boost] Template troubles.
From: Noah Roberts (roberts.noah_at_[hidden])
Date: 2008-12-10 13:55:00
Robert Jones wrote:
> On Wed, Dec 10, 2008 at 10:20 AM, Neil Groves <neil_at_[hidden]>wrote:
>
>> Neither of these are exact matches... is this deliberate? Or did you mean:
>>
>> template<typename T, std::size_t sz>
>> void assign(T (&assignee)[sz][sz], const T(&value)[sz][sz])
>> {
>> }
>>
>> I wondered this, because this modification makes it compile on Visual C++
>> because it is an exact match.
>>
>>
> Hi Neil
>
> Ultimately the signature you suggest is what I want to call, however I was
> hoping to achieve this via recursive instantiation, largely because looping
> over one index in the implementation is easily achieved with a for_each
> loop and a bind() call, whereas looping over two indices is rather
> cumbersome.
Didn't realize you'd also asked here (should pay more attention to
destinations). I think I gave you an idea why this is happening in my
response. As to doing it recursively:
template < typename T, size_t s >
void assign(T (&dest)[s][s], const T (&orig)[s][s])
{
for (size_t i = 0; i < s; ++i) assign(dest[i], orig[i]);
}
should work...
untested.
As to extending this to arbitrary depth of arrays...you'll probably need
to use the boost preproc lib. I don't think even variadic templates
would help you here (and certainly wouldn't make it compile better in VS).
Note: adjusted the destinations so that everyone that's heard the
question has now heard the answers.