Two other kinds of static

[Mehrdad]

On 6/4/2011 6:36 AM, bearophile wrote:
> Time ago I have half-seriously suggested a "static static", to solve a small problem I've has in my code. foo is a function template, so even if bar is static, every instantiation of foo gets a different bar:
>
>
> auto foo(T)(int x) {
>      static bar = ...;
>      ...
> }
>
>
> A "static static" means there is only one bar shared for all instances of foo, this is something I have desired a bit to do:
>
> auto foo(T)(int x) {
>      static static bar = ...;
>      ...
> }
>
>
> Now I have found a bit of need for another kind of static :-) In C/C++ there isn't this need because they don't have nest functions as D (GCC supports nest functions, but they are not used much). An example:
>
>
> int foo() {
>      int bar() {
>          static(foo) int[10] spam;
>          //...
>      }
>      // ...
> }
>
>
> That means something like:
>
> int foo() {
>      int[10] spam;
>      // spam not visible here
>      int bar() {
>          // use spam here only
>      }
>      // spam not visible here
> }
>
> "spam" is static regarding the bar() function, but it's not static (so it's automatic) for foo() function. This is sometimes useful because I know how bar will be called (inside foo), but I don't know how foo() itself will be called and used, and generally foo() may be a recursive function. So this is wrong code, I can't set spam as a truly static variable:
>
>
> int foo() { // recursive
>      int bar() { // not recursive
>          static int[10] spam; // wrong
>          // ...
>      }
>
>      return bar() + foo();
> }
>
> Bye,
> bearophile
Why not just put your "static static" variable /outside/?