With -preview=nosharedaccess, I get:

int y = 2;
shared int x = y; // OK

assert(x == 2); // no error
y = x; // error

So for the assignment to y, reading x is an error and atomicLoad should be used instead. But is it an oversight that reading x in the assert is not an error?

I have also found this in a unittest in core.atomic:

    shared(size_t) i;

    atomicOp!"+="(i, cast(size_t) 1);
    assert(i == 1);

Is the assert somehow thread-safe?

On Thursday, 16 March 2023 at 12:32:34 UTC, Nick Treleaven wrote:

int y = 2;
shared int x = y; // OK

assert(x == 2); // no error
y = x; // error

This also does not error:

bool b = x == 3;

Filed:
https://issues.dlang.org/show_bug.cgi?id=23783

On Thursday, 16 March 2023 at 12:32:34 UTC, Nick Treleaven wrote:

int y = 2;
shared int x = y; // OK

assert(x == 2); // no error
y = x; // error

    shared(size_t) i;

    atomicOp!"+="(i, cast(size_t) 1);
    assert(i == 1);

I think it should be fine since i cannot be in a state where it gets modified and read at the same time.