static switch

[Shammah Chancellor]

On 2014-03-05 14:09:31 +0000, bearophile said:

> Orvid King wrote:
> 
>> couldn't the first be improved more by allowing something like:
>> 
>> T opOpAssign(string op : in("+", "-", "*", "/", "%", "^^", "&", "|", 
>> "^", "<<", ">>", ">>>"), T)(T x)
>> 
>> The `in` there is my attempt to disambiguate between this type of 
>> constraint and what I view as the most likely syntax for built-in 
>> tuples.
> 
> While a static switch could be a little handy (I have desired it few 
> times, despite a static foreach is much more needed), there's no strong 
> need for that "in", You can use something like (untested):
> 
> T opOpAssign(string op, T)(T x)
> if ("+ - * / % ^^ & | ^ << >> >>>".split.canFind(op))
> 
> Bye,
> bearophile

Actually, there is static foreach if you are iterating over a tuple.  
It's not always very obvious under what conditions the compiler 
evaluates foreach though.

-S