Where should I put a `condp` like function?

[Idan Arye]

On Thursday, 18 April 2013 at 14:26:08 UTC, deadalnix wrote:
> On Thursday, 18 April 2013 at 13:58:46 UTC, Idan Arye wrote:
>> Naturally - even as statements, a `switch` statement without a 
>> switch expression is no better than a chain of `if`-`else`s.
>>
>
> As mentioned before in other thread, LLVM is crazy good at 
> transforming if/else chains into switch statement, and GCC does 
> a good job at it as well.

A `switch` statement is faster than a `if`-`else` chain only when 
it can use a lookup table, and for the lookup table a switch 
expression is a must. Another precondition for a lookup table is 
that the test expressions are known at compile-time.

The given example has none - there is no switch expression(though 
one may argue that you can use `true` as the switch expression) 
and the test expressions are function calls calculated at runtime.

If the compiler can translate a `if`-`else` chain to a `switch` 
statement - then it should have probably been a `switch` 
statement in the first place. That way it would have also been 
more readable.