https://issues.dlang.org/show_bug.cgi?id=21043

          Issue ID: 21043
           Summary: Diagnostic for autogenerated opAssign needs to improve
           Product: D
           Version: D2
          Hardware: x86
                OS: All
            Status: NEW
          Severity: minor
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: andrej.mitrovich@gmail.com

-----
struct S
{
    ~this () { }
}

void main () @safe
{
    S[int] map;
    map[1] = S.init;
}
-----

$ dmd test.d
> test.d(9): Error: @safe function D main cannot call @system generated function test.S.opAssign
> test.d(1):        test.S.opAssign is declared here

This doesn't actually say where the problem is. The issue is the @system destructor. Marking that destructor @safe solves the issue. Maybe the diagnostic should say that.

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