Simplification of @trusted

[Walter Bright]

On 6/17/2021 8:59 AM, H. S. Teoh wrote:
> What are the actual advantages of code being marked pure?  I'm all for
> generalizing pure, but does it bring enough actual benefits to be worth
> the effort?
> 
> I'm not talking about theoretical benefits, but actual benefits that the
> compiler can actually make use of to emit better code.  I used to be a
> big fan of pure, but in practice I've found that it doesn't make *that*
> much of a difference in terms of codegen.  Maybe I'm missing something,
> in which case I'd love to be enlightened.

You're right it doesn't make that much difference in code quality. What it 
*does* provide is:

1. makes it easy to reason about

2. makes unit testing easy

Just think about trying to unit test a function that side-loads various globals.