Re: 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)