[Issue 18003] New: assert performs implicit conversion of mutable local static char array to string

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=18003

          Issue ID: 18003
           Summary: assert performs implicit conversion of mutable local
                    static char array to string
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: hsteoh at quickfur.ath.cx

Code:
------
void f() {
        char[6] err = "Argh!";
        assert(0, err[0 .. $]);
}
void main() {
        f();
}
------

In the assert output, the message is garbled because it's a slice of the local
variable `err`, which has gone out of scope by the time the error message is
displayed.

Expected behaviour: assert() should not allow mutable char[] as second
argument, or the compiler should not allow implicit conversion of a mutable
char[] slice to immutable(char)[].

--