{"$message_type":"diagnostic","message":"the type `[(std::option::Option<T>, std::option::Option<u8>)]` cannot be indexed by `std::option::Option<u8>`","code":{"code":"E0277","explanation":"You tried to use a type which doesn't implement some trait in a place which\nexpected that trait.\n\nErroneous code example:\n\n```compile_fail,E0277\n// here we declare the Foo trait with a bar method\ntrait Foo {\n    fn bar(&self);\n}\n\n// we now declare a function which takes an object implementing the Foo trait\nfn some_func<T: Foo>(foo: T) {\n    foo.bar();\n}\n\nfn main() {\n    // we now call the method with the i32 type, which doesn't implement\n    // the Foo trait\n    some_func(5i32); // error: the trait bound `i32 : Foo` is not satisfied\n}\n```\n\nIn order to fix this error, verify that the type you're using does implement\nthe trait. Example:\n\n```\ntrait Foo {\n    fn bar(&self);\n}\n\n// we implement the trait on the i32 type\nimpl Foo for i32 {\n    fn bar(&self) {}\n}\n\nfn some_func<T: Foo>(foo: T) {\n    foo.bar(); // we can now use this method since i32 implements the\n               // Foo trait\n}\n\nfn main() {\n    some_func(5i32); // ok!\n}\n```\n\nOr in a generic context, an erroneous code example would look like:\n\n```compile_fail,E0277\nfn some_func<T>(foo: T) {\n    println!(\"{:?}\", foo); // error: the trait `core::fmt::Debug` is not\n                           //        implemented for the type `T`\n}\n\nfn main() {\n    // We now call the method with the i32 type,\n    // which *does* implement the Debug trait.\n    some_func(5i32);\n}\n```\n\nNote that the error here is in the definition of the generic function. Although\nwe only call it with a parameter that does implement `Debug`, the compiler\nstill rejects the function. It must work with all possible input types. In\norder to make this example compile, we need to restrict the generic type we're\naccepting:\n\n```\nuse std::fmt;\n\n// Restrict the input type to types that implement Debug.\nfn some_func<T: fmt::Debug>(foo: T) {\n    println!(\"{:?}\", foo);\n}\n\nfn main() {\n    // Calling the method is still fine, as i32 implements Debug.\n    some_func(5i32);\n\n    // This would fail to compile now:\n    // struct WithoutDebug;\n    // some_func(WithoutDebug);\n}\n```\n\nRust only looks at the signature of the called function, as such it must\nalready specify all requirements that will be used for every type parameter.\n"},"level":"error","spans":[{"file_name":"src/main.rs","byte_start":2447,"byte_end":2459,"line_start":72,"line_end":72,"column_start":23,"column_end":35,"is_primary":true,"text":[{"text":"            self.list[current_node]","highlight_start":23,"highlight_end":35}],"label":"slice indices are of type `usize` or ranges of `usize`","suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"the trait `std::slice::SliceIndex<[(std::option::Option<T>, std::option::Option<u8>)]>` is not implemented for `std::option::Option<u8>`, which is required by `std::vec::Vec<(std::option::Option<T>, std::option::Option<u8>)>: std::ops::Index<_>`","code":null,"level":"help","spans":[],"children":[],"rendered":null},{"message":"required for `std::vec::Vec<(std::option::Option<T>, std::option::Option<u8>)>` to implement `std::ops::Index<std::option::Option<u8>>`","code":null,"level":"note","spans":[],"children":[],"rendered":null}],"rendered":"\u001b[0m\u001b[1m\u001b[38;5;9merror[E0277]\u001b[0m\u001b[0m\u001b[1m: the type `[(std::option::Option<T>, std::option::Option<u8>)]` cannot be indexed by `std::option::Option<u8>`\u001b[0m\n\u001b[0m  \u001b[0m\u001b[0m\u001b[1m\u001b[38;5;12m--> \u001b[0m\u001b[0msrc/main.rs:72:23\u001b[0m\n\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[38;5;12m|\u001b[0m\n\u001b[0m\u001b[1m\u001b[38;5;12m72\u001b[0m\u001b[0m \u001b[0m\u001b[0m\u001b[1m\u001b[38;5;12m|\u001b[0m\u001b[0m \u001b[0m\u001b[0m            self.list[current_node]\u001b[0m\n\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[38;5;12m| \u001b[0m\u001b[0m                      \u001b[0m\u001b[0m\u001b[1m\u001b[38;5;9m^^^^^^^^^^^^\u001b[0m\u001b[0m \u001b[0m\u001b[0m\u001b[1m\u001b[38;5;9mslice indices are of type `usize` or ranges of `usize`\u001b[0m\n\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[38;5;12m|\u001b[0m\n\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[38;5;12m= \u001b[0m\u001b[0m\u001b[1mhelp\u001b[0m\u001b[0m: the trait `std::slice::SliceIndex<[(std::option::Option<T>, std::option::Option<u8>)]>` is not implemented for `std::option::Option<u8>`, which is required by `std::vec::Vec<(std::option::Option<T>, std::option::Option<u8>)>: std::ops::Index<_>`\u001b[0m\n\u001b[0m   \u001b[0m\u001b[0m\u001b[1m\u001b[38;5;12m= \u001b[0m\u001b[0m\u001b[1mnote\u001b[0m\u001b[0m: required for `std::vec::Vec<(std::option::Option<T>, std::option::Option<u8>)>` to implement `std::ops::Index<std::option::Option<u8>>`\u001b[0m\n\n"}
{"$message_type":"diagnostic","message":"aborting due to 1 previous error","code":null,"level":"error","spans":[],"children":[],"rendered":"\u001b[0m\u001b[1m\u001b[38;5;9merror\u001b[0m\u001b[0m\u001b[1m: aborting due to 1 previous error\u001b[0m\n\n"}
{"$message_type":"diagnostic","message":"For more information about this error, try `rustc --explain E0277`.","code":null,"level":"failure-note","spans":[],"children":[],"rendered":"\u001b[0m\u001b[1mFor more information about this error, try `rustc --explain E0277`.\u001b[0m\n"}