Bad array indexing is considered deadly

[ketmar via Digitalmars-d]

Steven Schveighoffer wrote:

> On 5/31/17 10:07 AM, Steven Schveighoffer wrote:
>
>> Here is complete implementation (should be @safe too):
>>
>> struct ExArr(T, size_t dim)
>> {
>>     T[dim] _value;
>>     alias _value this;
>>     ref inout(T) opIndex(size_t idx, string fname = __FILE__, size_t
>> linenum = __LINE__) inout
>>     {
>>         if(idx >= dim)
>>             throw new Exception("Index out of bounds", fname, linenum);
>>         static ref x(ref inout(T[dim]) val, size_t i) @trusted { return
>> val.ptr[i]; }
>>         return x(_value, idx);
>>     }
>> }
>
> Just realized, that @trusted escape is just so unnecessarily verbose.
>
> struct ExArr(T, size_t dim)
> {
>      T[dim] _value;
>      alias _value this;
>      ref inout(T) opIndex(size_t idx, string fname = __FILE__, size_t 
> linenum = __LINE__) inout @trusted
>      {
>          if(idx >= dim)
>              throw new Exception("Index out of bounds", fname, linenum);
>          return _value.ptr[idx];
>      }
> }
>
> -Steve

bonus point: you can include index and length in error message! (something 
i really miss in dmd range error)