/*
REQUIRED_ARGS: -preview=systemVariables
TEST_OUTPUT:
---
fail_compilation/systemvariables_struct.d(31): Error: accessing `@system` field `S.syst` is not allowed in a `@safe` function
fail_compilation/systemvariables_struct.d(32): Error: accessing `@system` field `S.syst` is not allowed in a `@safe` function
fail_compilation/systemvariables_struct.d(33): Error: accessing `@system` field `S.syst` is not allowed in a `@safe` function
fail_compilation/systemvariables_struct.d(36): Error: accessing `@system` field `S.syst` is not allowed in a `@safe` function
fail_compilation/systemvariables_struct.d(37): Error: accessing `@system` field `S.syst` is not allowed in a `@safe` function
fail_compilation/systemvariables_struct.d(38): Error: accessing `@system` field `S.syst` is not allowed in a `@safe` function
fail_compilation/systemvariables_struct.d(54): Error: accessing `@system` field `S2.syst` is not allowed in a `@safe` function
fail_compilation/systemvariables_struct.d(55): Error: accessing `@system` field `S2.syst` is not allowed in a `@safe` function
fail_compilation/systemvariables_struct.d(56): Error: accessing `@system` field `S.syst` is not allowed in a `@safe` function
fail_compilation/systemvariables_struct.d(57): Error: accessing `@system` field `S.syst` is not allowed in a `@safe` function
---
*/

// http://dlang.org/dips/1035

struct S
{
    @system S* syst;
    @safe S* safe;
}

void aggregate() @safe
{
    S s0;

    // write access
    s0.syst = null;
    __traits(getMember, s0, "syst") = null;
    s0.tupleof[0] = null;

    // read access
    auto a0 = s0.syst;
    auto a1 = __traits(getMember, s0, "syst");
    auto a2 = s0.tupleof[0];

    S s1;
    s1 = s0; // allowed
}

struct S2
{
    @system S syst;
    @safe   S safe;
}

@safe S2 gs2;

void aggregate2() @safe
{
    gs2.syst.syst = null;
    gs2.syst.safe = null;
    gs2.safe.syst = null;
    gs2.safe.syst.safe = null;

    gs2.safe.safe = null; // allowed
}