Dylan DPC 5ccdf1f6f7 Rollup merge of #98839 - 5225225:assert_transmute_copy_size, r=thomcc ... Add assertion that `transmute_copy`'s U is not larger than T This is called out as a safety requirement in the docs, but because knowing this can be done at compile time and constant folded (just like the `align_of` branch is removed), we can just panic here. I've looked at the asm (using `cargo-asm`) of a function that both is correct and incorrect, and the panic is completely removed, or is unconditional, without needing build-std. I don't expect this to cause much breakage in the wild. I scanned through https://miri.saethlin.dev/ub for issues that would look like this (error: Undefined Behavior: memory access failed: alloc1768 has size 1, so pointer to 8 bytes starting at offset 0 is out-of-bounds), but couldn't find any. That doesn't rule out it happening in crates tested that fail earlier for some other reason, though, but it indicates that doing this is rare, if it happens at all. A crater run for this would need to be build and test, since this is a runtime thing. Also added a few more transmute_copy tests.		2022-07-18 21:14:42 +05:30
..
benches	Add unicode fast path to is_printable	2022-05-31 10:51:35 +02:00
primitive_docs	Add primitive documentation to libcore	2021-09-12 02:23:08 +00:00
src	Rollup merge of #98839 - 5225225:assert_transmute_copy_size, r=thomcc	2022-07-18 21:14:42 +05:30
tests	Rollup merge of #98839 - 5225225:assert_transmute_copy_size, r=thomcc	2022-07-18 21:14:42 +05:30
Cargo.toml	Avoid use of rand::thread_rng in stdlib benchmarks	2022-05-02 00:08:21 -07:00