From dc53cfea7eb75b941e05e45fc7d8c412fd2a1bcd Mon Sep 17 00:00:00 2001 From: Esteban Küber Date: Sat, 22 Aug 2020 17:24:26 -0700 Subject: Add test cases and address review comments --- ...point-to-type-err-cause-on-impl-trait-return.rs | 35 +++++++ ...t-to-type-err-cause-on-impl-trait-return.stderr | 110 ++++++++++++++++++++- 2 files changed, 143 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/test/ui/point-to-type-err-cause-on-impl-trait-return.rs b/src/test/ui/point-to-type-err-cause-on-impl-trait-return.rs index 1a477e5db99..fa7664a83ee 100644 --- a/src/test/ui/point-to-type-err-cause-on-impl-trait-return.rs +++ b/src/test/ui/point-to-type-err-cause-on-impl-trait-return.rs @@ -63,4 +63,39 @@ fn dog() -> impl std::fmt::Display { } } +fn hat() -> dyn std::fmt::Display { //~ ERROR return type cannot have an unboxed trait object + match 13 { + 0 => { + return 0i32; + } + _ => { + 1u32 + } + } +} + +fn pug() -> dyn std::fmt::Display { //~ ERROR return type cannot have an unboxed trait object + match 13 { + 0 => 0i32, + 1 => 1u32, //~ ERROR `match` arms have incompatible types + _ => 2u32, + } +} + +fn man() -> dyn std::fmt::Display { //~ ERROR return type cannot have an unboxed trait object + if false { + 0i32 + } else { + 1u32 //~ ERROR `if` and `else` have incompatible types + } +} + +fn apt() -> impl std::fmt::Display { + if let Some(42) = Some(42) { + 0i32 + } else { + 1u32 //~ ERROR `if` and `else` have incompatible types + } +} + fn main() {} diff --git a/src/test/ui/point-to-type-err-cause-on-impl-trait-return.stderr b/src/test/ui/point-to-type-err-cause-on-impl-trait-return.stderr index 4265381eb40..eb4dc45c8a9 100644 --- a/src/test/ui/point-to-type-err-cause-on-impl-trait-return.stderr +++ b/src/test/ui/point-to-type-err-cause-on-impl-trait-return.stderr @@ -207,6 +207,112 @@ LL | 0 => Box::new(0i32), LL | 1 => Box::new(1u32), | -error: aborting due to 8 previous errors +error[E0308]: `if` and `else` have incompatible types + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:97:9 + | +LL | / if let Some(42) = Some(42) { +LL | | 0i32 + | | ---- expected because of this +LL | | } else { +LL | | 1u32 + | | ^^^^ expected `i32`, found `u32` +LL | | } + | |_____- `if` and `else` have incompatible types + | +help: you could change the return type to be a boxed trait object + | +LL | fn apt() -> Box { + | ^^^^^^^ ^ +help: if you change the return type to expect trait objects, box the returned expressions + | +LL | Box::new(0i32) +LL | } else { +LL | Box::new(1u32) + | + +error[E0746]: return type cannot have an unboxed trait object + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:66:13 + | +LL | fn hat() -> dyn std::fmt::Display { + | ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time + | + = note: for information on trait objects, see + = note: if all the returned values were of the same type you could use `impl std::fmt::Display` as the return type + = note: for information on `impl Trait`, see + = note: you can create a new `enum` with a variant for each returned type +help: return a boxed trait object instead + | +LL | fn hat() -> Box { +LL | match 13 { +LL | 0 => { +LL | return Box::new(0i32); +LL | } +LL | _ => { + ... + +error[E0308]: `match` arms have incompatible types + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:80:14 + | +LL | / match 13 { +LL | | 0 => 0i32, + | | ---- this is found to be of type `i32` +LL | | 1 => 1u32, + | | ^^^^ expected `i32`, found `u32` +LL | | _ => 2u32, +LL | | } + | |_____- `match` arms have incompatible types + +error[E0746]: return type cannot have an unboxed trait object + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:77:13 + | +LL | fn pug() -> dyn std::fmt::Display { + | ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time + | + = note: for information on trait objects, see + = note: if all the returned values were of the same type you could use `impl std::fmt::Display` as the return type + = note: for information on `impl Trait`, see + = note: you can create a new `enum` with a variant for each returned type +help: return a boxed trait object instead + | +LL | fn pug() -> Box { +LL | match 13 { +LL | 0 => Box::new(0i32), +LL | 1 => Box::new(1u32), +LL | _ => Box::new(2u32), + | + +error[E0308]: `if` and `else` have incompatible types + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:89:9 + | +LL | / if false { +LL | | 0i32 + | | ---- expected because of this +LL | | } else { +LL | | 1u32 + | | ^^^^ expected `i32`, found `u32` +LL | | } + | |_____- `if` and `else` have incompatible types + +error[E0746]: return type cannot have an unboxed trait object + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:85:13 + | +LL | fn man() -> dyn std::fmt::Display { + | ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time + | + = note: for information on trait objects, see + = note: if all the returned values were of the same type you could use `impl std::fmt::Display` as the return type + = note: for information on `impl Trait`, see + = note: you can create a new `enum` with a variant for each returned type +help: return a boxed trait object instead + | +LL | fn man() -> Box { +LL | if false { +LL | Box::new(0i32) +LL | } else { +LL | Box::new(1u32) + | + +error: aborting due to 14 previous errors -For more information about this error, try `rustc --explain E0308`. +Some errors have detailed explanations: E0308, E0746. +For more information about an error, try `rustc --explain E0308`. -- cgit 1.4.1-3-g733a5