Files
serde/serde_derive/src/try.rs
T
David Tolnay dd1f4b483e Make it clearer that the private implementation details are private
Both of these modules are doc(hidden) and commented "Not public API",
but incorrect downstream code sometimes still references them. Naming
the module __private will make it more likely to be noticed in code
review.
2021-01-08 19:55:31 -08:00

25 lines
912 B
Rust

use proc_macro2::{Punct, Spacing, TokenStream};
// None of our generated code requires the `From::from` error conversion
// performed by the standard library's `try!` macro. With this simplified macro
// we see a significant improvement in type checking and borrow checking time of
// the generated code and a slight improvement in binary size.
pub fn replacement() -> TokenStream {
// Cannot pass `$expr` to `quote!` prior to Rust 1.17.0 so interpolate it.
let dollar = Punct::new('$', Spacing::Alone);
quote! {
#[allow(unused_macros)]
macro_rules! try {
(#dollar __expr:expr) => {
match #dollar __expr {
_serde::__private::Ok(__val) => __val,
_serde::__private::Err(__err) => {
return _serde::__private::Err(__err);
}
}
}
}
}
}