This patch series introduces a new `FromPrimitive` trait along with its
corresponding derive macro.
A few enhancements were made to the custom `quote!` macro to write the
derive macro. These include support for additional punctuation tokens
and a fix for an unused variable warning when quoting simple forms.
Detailed information about these enhancements is provided in the
relevant patches.
While cleaning up the implementations, I came across an alternative
form of the `FromPrimitive` trait that might better suit the current
use case. Since types that implement this trait may often rely on just
one `from_*` method, the following design could be a simpler fit:
trait FromPrimitive: Sized {
type Primitive;
fn from_bool(b: bool) -> Option<Self>
where
<Self as FromPrimitive>::Primitive: From<bool>,
{
Self::from_primitive(b.into())
}
fn from_primitive(n: Self::Primitive) -> Option<Self>;
}
This is just a thought and not something I feel strongly about, but I
wanted to share it in case others find the idea useful. Feedback or
suggestions are very welcome.
The original discussion of FromPrimitive can be found on Zulip [1].
[1]
https://rust-for-linux.zulipchat.com/#narrow/channel/288089/topic/x/near/524427350
Jesung Yang (4):
rust: introduce `FromPrimitive` trait
rust: macros: extend custom `quote!` macro
rust: macros: prefix variable `span` with underscore
rust: macros: add derive macro for `FromPrimitive`
rust/kernel/convert.rs | 154 +++++++++++++++++++++++++++++
rust/kernel/lib.rs | 1 +
rust/macros/convert.rs | 217 +++++++++++++++++++++++++++++++++++++++++
rust/macros/lib.rs | 71 ++++++++++++++
rust/macros/quote.rs | 46 ++++++++-
5 files changed, 487 insertions(+), 2 deletions(-)
create mode 100644 rust/kernel/convert.rs
create mode 100644 rust/macros/convert.rs
base-commit: dc35ddcf97e99b18559d0855071030e664aae44d
--
2.39.5
