Bug 10864 – [REG 2.064][PERFORMANCE] new Safe appender is slower than "~="

The new Appender is now @safe and pure. This was done mostly by https://github.com/D-Programming-Language/phobos/pull/1337 , which is done with heavy usage of the trusted lambda idiom, eg: () @trusted {unsafe code here;} (); The problem is that doing this has a very high runtime cost. Currently, my benches get improved performance by *not* using appender. This can be fixed either by using the same "named" idiom: void do_it() @trusted {unsafe code here;} do_it(); (for reasons I do not understand, *that* has no extra runtime cost, even in non-optimized/non-inline mode). Or by fixing: http://d.puremagic.com/issues/show_bug.cgi?id=10848 Appender being one of the "foundation" blocks of most of phobos, this is arguably a permance-blocker.

We can create a single @trusted `impl*` function and then call it from main one. Then e.g. make a fake call to stuff wich defines @safe-ness to get right attributes.

Can't remember which pull exactly fixes it, but it is fixed now.