8a461d940c
suggest adding a where-clause when there is an unmet trait-bound that can be satisfied if some type can implement it.
40 lines
1.1 KiB
Rust
40 lines
1.1 KiB
Rust
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// Test that there is no way to get a generic type `T` to be
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// considered as `Reflect` (or accessible via something that is
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// considered `Reflect`) without a reflect bound, but that any
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// concrete type works fine. Note that object types are tested
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// separately.
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use std::marker::Reflect;
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use std::io::Write;
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struct Struct<T>(T);
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fn is_reflect<T:Reflect>() { }
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fn c<T>() {
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is_reflect::<Struct<T>>(); //~ ERROR E0277
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}
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fn ok_c<T: Reflect>() {
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is_reflect::<Struct<T>>(); // OK
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}
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fn d<T>() {
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is_reflect::<(i32, T)>(); //~ ERROR E0277
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}
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fn main() {
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is_reflect::<&i32>(); // OK
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is_reflect::<Box<Write>>(); // OK
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}
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