4 ms·

This is not strict aliasing as far as I understand. Strict aliasing is about inference of distinctness of pointers. The case here is that an invalidly typed poi

• gpderetta 4y ago
  The type aliasing rule is also known as the strict aliasing rule, see for example: https://en.cppreference.com/w/c/language/object https://en.cppreference.com/w/c/language/object
  • jstimpfle 4y ago
    After skimming this, I still think the strict aliasing rule is used by compiler to avoid re-reads. What you were talking about is probably something else, maybe an "invalid lvalue access" as per your link.
    • gpderetta 4y ago
      From cpp reference: "Strict Aliasing: Given an object with effective type T1, using an lvalue expression (typically, dereferencing a pointer) of a different type T2 is undefined behavior, unless [non relevant exceptions omitted]". In this case the expression has type bool and the underlying object has type int, so it is a straightforward strict aliasing violation. With GCC you can compile with -fno-strict-aliasing to ignore this rule. But now you fall afoul of the rule that prevents accessing an invalid representation (i.e. a trap-representation) of an object. This rule is also described in the link I posted before, under the object representation paragraph.
      • jstimpfle 4y ago
        ok, so in the case above, it's both (if strict aliasing is active). Makes sense now.