Why is this claimed dereferencing type-punned pointer warning compiler-specific?

Question

I\'ve read various posts on Stack Overflow RE: the derefercing type-punned pointer error. My understanding is that the error is essentially the compiler warning of the danger of

Answer 1

Although C was designed for machines which use the same representation for all pointers, the authors of the Standard wanted to make the language usable on machines that use different representations for pointers to different types of objects. Therefore, they did not require that machines which use different pointer representations for different kinds of pointers support a "pointer to any kind of pointer" type, even though many machines could do so at zero cost.

Before the Standard was written, implementations for platforms that used the same representation for all pointer types would unanimously allow a void** to be used, at least with suitable casting, as a "pointer to any pointer". The authors of the Standard almost certainly recognized that this would be useful on platforms that supported it, but since it couldn't be universally supported they declined to mandate it. Instead, they expected that quality implementation would process such constructs as what the Rationale would describe as a "popular extension", in cases where doing so would make sense.