diff --git a/src/librustc/diagnostics.rs b/src/librustc/diagnostics.rs index 0857fb3258eec..0f83cdff5372c 100644 --- a/src/librustc/diagnostics.rs +++ b/src/librustc/diagnostics.rs @@ -256,6 +256,21 @@ See [RFC 911] for more details on the design of `const fn`s. [RFC 911]: https://github.com/rust-lang/rfcs/blob/master/text/0911-const-fn.md "##, +E0016: r##" +Blocks in constants may only contain items (such as constant, function +definition, etc...) and a tail expression. Example: + +``` +const FOO: i32 = { let x = 0; x }; // 'x' isn't an item! +``` + +To avoid it, you have to replace the non-item object: + +``` +const FOO: i32 = { const X : i32 = 0; X }; +``` +"##, + E0018: r##" The value of static and const variables must be known at compile time. You can't cast a pointer as an integer because we can't know what value the @@ -279,6 +294,42 @@ println!("{}", Y); ``` "##, +E0019: r##" +A function call isn't allowed in the const's initialization expression +because the expression's value must be known at compile-time. Example of +erroneous code: + +``` +enum Test { + V1 +} + +impl Test { + fn test(&self) -> i32 { + 12 + } +} + +fn main() { + const FOO: Test = Test::V1; + + const A: i32 = FOO.test(); // You can't call Test::func() here ! +} +``` + +Remember: you can't use a function call inside a const's initialization +expression! However, you can totally use it elsewhere you want: + +``` +fn main() { + const FOO: Test = Test::V1; + + FOO.func(); // here is good + let x = FOO.func(); // or even here! +} +``` +"##, + E0020: r##" This error indicates that an attempt was made to divide by zero (or take the remainder of a zero divisor) in a static or constant expression. @@ -950,9 +1001,7 @@ static mut BAR: Option> = None; register_diagnostics! { - E0016, E0017, - E0019, E0022, E0038, E0109, diff --git a/src/librustc_typeck/diagnostics.rs b/src/librustc_typeck/diagnostics.rs index d89174295a892..fa29f8f1dcea9 100644 --- a/src/librustc_typeck/diagnostics.rs +++ b/src/librustc_typeck/diagnostics.rs @@ -211,6 +211,150 @@ Reference: http://doc.rust-lang.org/reference.html#trait-objects "##, +E0034: r##" +The compiler doesn't know what method to call because more than one method +has the same prototype. Example: + +``` +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() { + ::foo() +} +``` +"##, + +E0035: r##" +You tried to give a type parameter where it wasn't needed. Bad example: + +``` +struct Test; + +impl Test { + fn method(&self) {} +} + +fn main() { + let x = Test; + + x.method::(); // Error: Test::method doesn't need type parameter! +} +``` + +To fix this error, just remove the type parameter: + +``` +struct Test; + +impl Test { + fn method(&self) {} +} + +fn main() { + let x = Test; + + x.method(); // OK, we're good! +} +``` +"##, + +E0036: r##" +This error occurrs when you pass too many or not enough type parameters to +a method. Example: + +``` +struct Test; + +impl Test { + fn method(&self, v: &[T]) -> usize { + v.len() + } +} + +fn main() { + let x = Test; + let v = &[0i32]; + + x.method::(v); // error: only one type parameter is expected! +} +``` + +To fix it, just specify a correct number of type parameters: + +``` +struct Test; + +impl Test { + fn method(&self, v: &[T]) -> usize { + v.len() + } +} + +fn main() { + let x = Test; + let v = &[0i32]; + + x.method::(v); // OK, we're good! +} +``` + +Please note on the last example that we could have called `method` like this: + +``` +x.method(v); +``` +"##, + E0040: r##" It is not allowed to manually call destructors in Rust. It is also not necessary to do this since `drop` is called automatically whenever a value goes @@ -1320,9 +1464,6 @@ For more information see the [opt-in builtin traits RFC](https://github.com/rust } register_diagnostics! { - E0034, // multiple applicable methods in scope - E0035, // does not take type parameters - E0036, // incorrect number of type parameters given for this method E0044, // foreign items may not have type parameters E0045, // variadic function must have C calling convention E0068,