Afaik loop {} has never been UB, however because llvm started as a c++ compiled where it is, this has been causing miscompilations in rust and C for… nearly two decades (llvm issue 965).

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cowlevel 2 hours ago | parent [-]

Since the Rust language is defined by the Rust compiler and has no other specification, if it's UB in the compiler then it's UB in the language.

	▲	masklinn 33 minutes ago \| parent \| next [-]
		And this, kids, is how you get called Billy Madison. May god have mercy on your soul, cowlevel1.
	▲	pmarreck 7 minutes ago \| parent \| prev [-]
		Rust has no formal spec? Really?