Temporary @trusted scope

[Steven Schveighoffer]

On 12/18/18 6:29 AM, Simen Kjærås wrote:
> On Tuesday, 18 December 2018 at 10:14:50 UTC, Per Nordlöw wrote:
>> What's the preferred way of creating a temporary @trusted scope 
>> without writing a separate  function?
> 
> Jonathan's idea might also be encapsulated in a function, just like 
> assumeUnique in Phobos:
> 
> import std.stdio;
> 
> template unsafe(alias fn) {
>      @trusted auto unsafe(T...)(T args) {
>          return fn(args);
>      }
> }
> 
> @system void fun(int n) {
>      writeln("foo!");
> }
> 
> @safe unittest {
>      unsafe!({
>          fun(2);
>      });
> 
>      unsafe!fun(2);
> }

Wow, I really like this. The only real problem is that one generally 
searches for @trusted when looking for unsafe code, but unsafe is pretty 
obvious too. Also, args should be auto ref.

Only thing better I can think of (for the second example) is to define a 
prototype with the correct information, only with @trusted (and specify 
the mangle). But any decent compiler should get rid of any overhead there.

-Steve