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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /compiler/rustc_error_codes/src/error_codes/E0034.md | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compiler/rustc_error_codes/src/error_codes/E0034.md')
-rw-r--r-- | compiler/rustc_error_codes/src/error_codes/E0034.md | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/compiler/rustc_error_codes/src/error_codes/E0034.md b/compiler/rustc_error_codes/src/error_codes/E0034.md new file mode 100644 index 000000000..2a21f3441 --- /dev/null +++ b/compiler/rustc_error_codes/src/error_codes/E0034.md @@ -0,0 +1,86 @@ +The compiler doesn't know what method to call because more than one method +has the same prototype. + +Erroneous code example: + +```compile_fail,E0034 +struct Test; + +trait Trait1 { + fn foo(); +} + +trait Trait2 { + fn foo(); +} + +impl Trait1 for Test { fn foo() {} } +impl Trait2 for Test { fn foo() {} } + +fn main() { + Test::foo() // error, which foo() to call? +} +``` + +To avoid this error, you have to keep only one of them and remove the others. +So let's take our example and fix it: + +``` +struct Test; + +trait Trait1 { + fn foo(); +} + +impl Trait1 for Test { fn foo() {} } + +fn main() { + Test::foo() // and now that's good! +} +``` + +However, a better solution would be using fully explicit naming of type and +trait: + +``` +struct Test; + +trait Trait1 { + fn foo(); +} + +trait Trait2 { + fn foo(); +} + +impl Trait1 for Test { fn foo() {} } +impl Trait2 for Test { fn foo() {} } + +fn main() { + <Test as Trait1>::foo() +} +``` + +One last example: + +``` +trait F { + fn m(&self); +} + +trait G { + fn m(&self); +} + +struct X; + +impl F for X { fn m(&self) { println!("I am F"); } } +impl G for X { fn m(&self) { println!("I am G"); } } + +fn main() { + let f = X; + + F::m(&f); // it displays "I am F" + G::m(&f); // it displays "I am G" +} +``` |