Char.length

[John Colvin via Digitalmars-d]

On Thursday, 10 July 2014 at 17:01:45 UTC, Jane Doe wrote:
> One thing that bothers me quite a bit is that char's do not 
> have length. This makes it difficult in templates that can take 
> either strings or chars.
>
> While one can write a template that returns the length of a 
> string or char, I would imagine that this could be implemented 
> in the compiler more efficiently?
>
>     char.length always returns 1.
>
> Similarly, it would be nice to be able to use [] on chars.
>
>     char[x] returns char.
>
> Example:
>
>     auto last(T)(T s) { return s[s.length-1]; }
>
>     void main()
>     {
> 	writeln(last("asdf"));
> 	writeln(last('c'));       // fails!! But surely this should 
> work!
>     }
>
>
>
> http://dpaste.dzfl.pl/cba5a635d08e
>
>     Error: s must be an array or pointer type, not char
>     Error: no property 'length' for type 'char'
>
> Basically, I see no reason why char's can't be more confluent 
> with strings, at least on the surface. I would reduce code 
> bloat/specialization for no real reason.
>
> If the compile knows a type is a char then char.length = 1 and 
> char[x] = char. Shouldn't be hard or cause any problems?

It looks nice on the surface but it quite quickly unravels.

string and char are very different types: one is a single-byte 
value type, the other is a 16 byte (on x64) structure 
representing an arbitrary length window on to arbitrary memory.

The situations where they are interchangeable in code are the 
exceptions, not the rule.