Question

I’ve seen several assertions that C89 and C++03 define strict aliasing rules. I, however, cannot find that particular bit in the standard. My understanding was that strict aliasing rules were added in C99.

Answer 1

The C++03 standard has the following under §3.10 [basic.lval] p15:

If a program attempts to access the stored value of an object through an lvalue of other than one of the following types the behavior is undefined⁴⁸⁾:
— the dynamic type of the object,
— a cv-qualified version of the dynamic type of the object,
— a type that is the signed or unsigned type corresponding to the dynamic type of the object,
— a type that is the signed or unsigned type corresponding to a cv-qualified version of the dynamic type of the object,
— an aggregate or union type that includes one of the aforementioned types among its members (including, recursively, a member of a subaggregate or contained union),
— a type that is a (possibly cv-qualified) base class type of the dynamic type of the object,
— a char or unsigned char type.

Footnote:

⁴⁸⁾ The intent of this list is to specify those circumstances in which an object may or may not be aliased.

This site also lists the sections in the other standards.