43 lines
1007 B
Rust
43 lines
1007 B
Rust
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#![feature(plugin)]
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#![feature(const_fn)]
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#![plugin(clippy)]
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#![deny(clippy_pedantic)]
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#![allow(unused, missing_docs_in_private_items)]
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fn do_nothing<T>(_: T) {}
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fn plus_one(value: usize) -> usize {
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value + 1
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}
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struct HasOption {
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field: Option<usize>,
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}
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impl HasOption {
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fn do_option_nothing(self: &HasOption, value: usize) {}
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fn do_option_plus_one(self: &HasOption, value: usize) -> usize {
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value + 1
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}
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}
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#[cfg_attr(rustfmt, rustfmt_skip)]
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fn main() {
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let x = HasOption { field: Some(10) };
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x.field.map(plus_one);
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let _ : Option<()> = x.field.map(do_nothing);
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x.field.map(do_nothing);
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//~^ ERROR called `map(f)` on an Option value where `f` is a nil function
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//~| HELP try this
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//~| SUGGESTION if let Some(...) = x.field { do_nothing(...) }
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x.field.map(do_nothing);
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//~^ ERROR called `map(f)` on an Option value where `f` is a nil function
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//~| HELP try this
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//~| SUGGESTION if let Some(...) = x.field { do_nothing(...) }
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}
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