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Diffstat (limited to 'vendor/darling/examples/supports_struct.rs')
-rw-r--r-- | vendor/darling/examples/supports_struct.rs | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/vendor/darling/examples/supports_struct.rs b/vendor/darling/examples/supports_struct.rs new file mode 100644 index 000000000..97a5bb9c0 --- /dev/null +++ b/vendor/darling/examples/supports_struct.rs @@ -0,0 +1,61 @@ +// The use of fields in debug print commands does not count as "used", +// which causes the fields to trigger an unwanted dead code warning. +#![allow(dead_code)] + +use darling::{ast, util, FromDeriveInput, FromField}; +use syn::{Ident, Type}; + +#[derive(Debug, FromField)] +#[darling(attributes(lorem))] +pub struct LoremField { + ident: Option<Ident>, + ty: Type, + #[darling(default)] + skip: bool, +} + +#[derive(Debug, FromDeriveInput)] +#[darling(attributes(lorem), supports(struct_named))] +pub struct Lorem { + ident: Ident, + data: ast::Data<util::Ignored, LoremField>, +} + +fn main() { + let good_input = r#"#[derive(Lorem)] +pub struct Foo { + #[lorem(skip)] + bar: bool, + + baz: i64, +}"#; + + let bad_input = r#"#[derive(Lorem)] + pub struct BadFoo(String, u32);"#; + + let parsed = syn::parse_str(good_input).unwrap(); + let receiver = Lorem::from_derive_input(&parsed).unwrap(); + let wrong_shape_parsed = syn::parse_str(bad_input).unwrap(); + let wrong_shape = Lorem::from_derive_input(&wrong_shape_parsed).expect_err("Shape was wrong"); + + println!( + r#" +INPUT: + +{} + +PARSED AS: + +{:?} + +BAD INPUT: + +{} + +PRODUCED ERROR: + +{} + "#, + good_input, receiver, bad_input, wrong_shape + ); +} |