Bug 23773 – array length assignment in assert condition should error

int[] a; if (a.length = i) {} // error assert(a.length = i); // not caught A variable assignment is caught: int i, j; if (i = j) {} // error assert(i = j); // error

Looks like this code needs modifying: https://github.com/dlang/dmd/pull/12165

But I do get an error: test.d(5): Error: cannot modify constant `a.length` And that happens because `a.length = i` gets analyzed before the compiler gets the chance to error about the assert. It makes sense that the assignment needs to be semantically correct before it's checked if it's in an assert. I don't think this bug report is valid.

But I do get an error: test.d(5): Error: cannot modify constant `a.length` And that happens because `a.length = i` gets analyzed before the compiler gets the chance to error about the assert. It makes sense that the assignment needs to be semantically correct before it's checked if it's in an assert. I don't think this bug report is valid.

Scratch that, when I tested locally I had a static array, instead of a dynamic one. The bug report is valid.

Well, the compiler rewrites `a.length = i` to `_d_arraysetlengthT(a, i)` so that's why the assert error is not caught.

@RazvanN7 created dlang/dmd pull request #14985 "Add a lowering field for AssignExp to store potential lowerings" mentioning this issue: - Add a lowering field for AssignExp to store potential lowerings and use it for array length expressions + Fix Issue 23773 https://github.com/dlang/dmd/pull/14985

dlang/dmd pull request #14985 "Add a `lowering` field for AssignExp to store potential lowerings" was merged into master: - e6df5b96bcf1c38f44d3a151fdaf6a2381e17564 by RazvanN7: Fix Issue 23773 - Add a lowering field for AssignExp to store potential lowerings and use it for array length expressions https://github.com/dlang/dmd/pull/14985