vector comparisons in C++

[Jason Merrill]

On 09/14/2012 09:59 AM, Marc Glisse wrote:
> * build_vector_type: don't use an opaque vector for the return type of
>    operator< (not sure what the point was of making it opaque?)

I think the point was to allow conversion of the result to a different 
vector type.  Why do you want it not to be opaque?

> * Disable (type)(a<b) -> (a<b)?type(true):type(false) for vectors.
>    It would be doable with vec_cond_expr, but I am not sure it helps.

Right.  It certainly doesn't help for integer vectors.

> +	      error_at (location, "comparing vectors with different "
> +				  "element types");

Let's print the vector types in these errors.

Jason