Against enforce()

[Don]

Kagamin wrote:
> Steven Schveighoffer Wrote:
> 
>> As long as the delegate does not access shared/global data, it should be  
>> able to be pure.  Even delegates which modify TLS data should be able to  
>> be pure (weak-pure, but still pure).

TLS variables are global and must not be accessed from any function 
marked as pure. With regard to purity, there isn't any difference 
between shared and TLS variables.

> Pure functions calling weakly pure functions are also weakly pure and so on.  This effectively leaves you without purity.

I presume you mean "Pure functions calling weakly pure functions *would 
also be* weakly pure and so on." ?