Make from_bits in bitflags! safe; add from_bits_truncate
#14208
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I've added |
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@omasanori Yeah, I just noticed that with the Travis failure. I'm working on a revised patch that merges the tests and also adds tests for |
Previously, the `from_bits` function in the `std::bitflags::bitflags` macro was marked as unsafe, as it did not check that the bits being converted actually corresponded to flags. This patch changes the function to check against the full set of possible flags and return an `Option` which is `None` if a non-flag bit is set. It also adds a `from_bits_truncate` function which simply zeros any bits not corresponding to a flag. This addresses the concern raised in rust-lang#13897
| if (bits & !$BitFlags::all().bits()) != 0 { | ||
| ::std::option::None | ||
| } else { | ||
| ::std::option::Some($BitFlags { bits: bits }) |
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Maybe use std::option; could make it cleaner.
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I didn't want to import the module as part of the macro, since that can pollute the macro client's namespace -- so I think the type signature, at least, needs to stay as is.
(Note that macros.rs in libstd follows the same pattern.)
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Fair enough, I have to admit I’m not used to declaring macros.
fix:add a case in which remainig is None in resolveing types when resolving hir path. fix rust-lang#14030 The variable type is being determined incorrectly This PR fixed a problem in which `go to definition` is jumping to the incorrect position because it was failing to resolve the type in case it defined in the module when resolving hir. In addition, I added a test for this issue and refactored the related code. This is my first PR and I am using a translation tool to write this text. Let me know if you have any problems.
Previously, the
from_bitsfunction in thestd::bitflags::bitflagsmacro was marked as unsafe, as it did not check that the bits being
converted actually corresponded to flags.
This patch changes the function to check against the full set of
possible flags and return an
Optionwhich isNoneif a non-flag bitis set. It also adds a
from_bits_truncatefunction which simply zerosany bits not corresponding to a flag.
This addresses the concern raised in
#13897