Why CTFE is context-sensitive?

[Pierre Talbot]

On Sunday, 26 January 2014 at 13:48:47 UTC, Timon Gehr wrote:
> On 01/26/2014 10:59 AM, Pierre Talbot wrote:
>> Hi,
>>
>> I was wondering why CTFE is context sensitive, why don't we 
>> check
>> every expressions and run the CTFE if it applies?
>
> When does it apply?

According to http://dlang.org/function.html#interpretation

* initialization of a static variable
* dimension of a static array
* argument for a template value parameter

As shown in the examples:

int square(int i) {
   return i * i;
}

void foo() {
   writeln(square(4)); // run time
}