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On Jan 10, 2016, at 17:55, Chris Angelico <rosuav@gmail.com> wrote:
You're missing that a 32-bit build of Python would then be allowed to use a 32-bit counter. But if the spec says "64-bit counter", then yeah, we can pretty much assume that it won't overflow.
As I understand it from Victor's PEP, the added cost of maintaining this counter is literally so small as to be unmeasurable against the cost of normal dict operations in microbenchmarks. If that's true, surely the cost of requiring a 64-bit counter is going to be acceptable? I realize that some MicroPython projects will be targeting platforms where there's no fast way to do an inc64 (or where the available compilers are too dumb to do it the fast way), but those projects are probably not going to want FAT Python anyway. On a P3 or later x86 or an ARM 7 or something like that, the cost should be more than acceptable. Or at least it's worth testing.