Re: [Boost-users] boost-users [shared_array] comparing the value.

From: Michael Linck (mgl_at_[hidden])
Date: 2007-10-25 19:21:03

It should be intelligent enough to deal with that.

mike

On Thu, 2007-10-25 at 15:01 -0700, chun ping wang wrote:
> hmm the thing is it compares all the array. And len might not be the
> actual size of the array. 
> 
> Example you cna have array X.
> x[0] = 25
> x[1] = 12
> x[2] = null
> x[3] = null
>  
> 
>  
> On 10/25/07, Michael Linck <mgl_at_[hidden]> wrote: 
>         The boost documentation states that the == operator "Compares
>         the stored
>         pointers of the two smart pointers." The phrase "smart
>         pointers" refers 
>         to the shared arrays themselves, because that's really all a
>         shared
>         array *is.*  So the operation described above is actually
>         equivalent to
>         what you outlined in item 2. of answering your own question.
>         
>         mike
>         
>         On Thu, 2007-10-25 at 11:22 -0700, chun ping wang wrote:
>         > Hi I notice boost shared_array compares the pointer address
>         not the
>         > pointer themselves. What would be the best way to compare
>         the actual 
>         > value of boost shared_array.
>         >
>         > 1.)
>         > shared_array<T> a;
>         > shared_array<T> b;
>         >
>         >
>         > 1.) return (a.len == b.len && (memcmp(a, b, len) == 0));
>         >
>         > or
>         >
>         > 2.)
>         > if (a.len != b.len)
>         >      return false;
>         > for (ptrdiff_t i  = 0; i != a.len; ++i)
>         >    if(a[i] != b[i])
>         >       return false;
>         >
>         > One that works ALL the times. 
>         >
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