What is your point? I already said that GCC defines it even though the C standard does not. As per the GCC developers:

> Type punning via unions is undefined behavior in both c and c++.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118141#c13

> One of the GCC developers told me explicitly that type punning through a union was UB in C, but defined by GCC when I asked

I just was citing the source of this for reference.