https://issues.dlang.org/show_bug.cgi?id=13639

          Issue ID: 13639
           Summary: std.internal.math.biguintcore.fromDecimalString from
                    @trusted to @safe fails unittests
           Product: D
           Version: D2
          Hardware: All
                OS: Linux
            Status: NEW
          Severity: minor
          Priority: P1
         Component: Phobos
          Assignee: nobody@puremagic.com
          Reporter: rburners@gmail.com

I created this PR https://github.com/D-Programming-Language/phobos/pull/2612 that makes some of std.bigint safe.

but wenn I mark std.internal.math.biguintcore.fromDecimalString as @safe instead of @trusted some unittests fail.

--