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Diffstat (limited to '')
-rw-r--r-- | vendor/serde_derive/src/try.rs | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/vendor/serde_derive/src/try.rs b/vendor/serde_derive/src/try.rs new file mode 100644 index 000000000..48cceebaa --- /dev/null +++ b/vendor/serde_derive/src/try.rs @@ -0,0 +1,24 @@ +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); + } + } + } + } + } +} |