Re-enable trivial bounds

[matthewjasper]

cc #50825

Remove implementations from global bounds in winnowing when there is ambiguity.

This results in the reverse of #24066 happening sometimes. I'm not sure if anything can be done about that though.

cc #48214

r? @nikomatsakis

[rust-highfive]

The job x86_64-gnu-llvm-3.9 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[00:50:29] ............................................i.......................................................
[00:50:33] ....................................................................................................
[00:50:36] ....................................................................................................
[00:50:40] ....................................................................................................
[00:50:43] .................................................................................F..................
[00:50:52] ....................................................................................................
[00:50:57] ....................................................................................................
[00:51:03] ..............................................................................i.....................
[00:51:08] ......................................................i.............................................
---
[00:51:29] failures:
[00:51:29] 
[00:51:29] ---- [ui] ui/feature-gate-trivial_bounds.rs stdout ----
[00:51:29] 
[00:51:29] error: /checkout/src/test/ui/feature-gate-trivial_bounds.rs:31: expected error not found: 
[00:51:29] 
[00:51:29] error: /checkout/src/test/ui/feature-gate-trivial_bounds.rs:62: expected error not found: 
[00:51:29] 
[00:51:29] error: 0 unexpected errors found, 2 expected errors not found
[00:51:29] status: exit code: 101
[00:51:29] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/feature-gate-trivial_bounds.rs" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/feature-gate-trivial_bounds/a" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/feature-gate-trivial_bounds/auxiliary" "-A" "unused"
[00:51:29] not found errors (from test file): [
[00:51:29]     Error {
[00:51:29]         line_num: 31,
[00:51:29]         kind: Some(
[00:51:29]         ),
[00:51:29]         ),
[00:51:29]         msg: ""
[00:51:29]     Error {
[00:51:29]         line_num: 62,
[00:51:29]         kind: Some(
[00:51:29]             Error
[00:51:29]             Error
[00:51:29]         ),
[00:51:29]         msg: ""
[00:51:29] ]
[00:51:29] 
[00:51:29] thread '[ui] ui/feature-gate-trivial_bounds.rs' panicked at 'explicit panic', tools/compiletest/src/runtest.rs:1283:13
[00:51:29] note: Run with `RUST_BACKTRACE=1` for a backtrace.
---
[00:51:29] 
[00:51:29] thread 'main' panicked at 'Some tests failed', tools/compiletest/src/main.rs:498:22
[00:51:29] 
[00:51:29] 
[00:51:29] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/compiletest" "--compile-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib" "--run-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib" "--rustc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "--src-base" "/checkout/src/test/ui" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--mode" "ui" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/usr/lib/llvm-3.9/bin/FileCheck" "--host-rustcflags" "-Crpath -O -Zunstable-options " "--target-rustcflags" "-Crpath -O -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--docck-python" "/usr/bin/python2.7" "--lldb-python" "/usr/bin/python2.7" "--gdb" "/usr/bin/gdb" "--quiet" "--llvm-version" "3.9.1\n" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--llvm-components" "" "--llvm-cxxflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"
[00:51:29] 
[00:51:29] 
[00:51:29] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[00:51:29] Build completed unsuccessfully in 0:02:48
[00:51:29] Build completed unsuccessfully in 0:02:48
[00:51:29] Makefile:58: recipe for target 'check' failed
[00:51:29] make: *** [check] Error 1

The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:069e7e16
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[matthewjasper]

Pushed a commit to fix #51044 as well

[rust-highfive]

The job x86_64-gnu-llvm-3.9 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[00:58:54] ............................................i.......................................................
[00:58:59] ....................................................................................................
[00:59:02] ....................................................................................................
[00:59:06] ....................................................................................................
[00:59:10] .................................................................................F..................
[00:59:21] ....................................................................................................
[00:59:27] ....................................................................................................
[00:59:34] ..............................................................................i.....................
[00:59:41] .......................................................i............................................
[00:59:41] .......................................................i............................................
[00:59:46] ...........................................................................ii.......................
[00:59:54] ....................................................................................................
[01:00:02] .....................................................................................i..............
[01:00:06] To only update this specific test, also pass `--test-args feature-gate-trivial_bounds.rs`
[01:00:06] error: 1 errors occurred comparing output.
[01:00:06] status: exit code: 101
[01:00:06] status: exit code: 101
[01:00:06] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/feature-gate-trivial_bounds.rs" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/feature-gate-trivial_bounds/a" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/feature-gate-trivial_bounds/auxiliary" "-A" "unused"
[01:00:06] ------------------------------------------
[01:00:06] 
[01:00:06] ------------------------------------------
[01:00:06] stderr:
[01:00:06] stderr:
[01:00:06] ------------------------------------------
[01:00:06] {"message":"the trait bound `i32: Foo` is not satisfied","code":{"code":"E0277","explanation":"\nYou tried to use a type which doesn't implement some trait in a place which\nexpected that trait. Erroneous 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\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\n// we implement the trait on the i32 type\nimpl Foo for i32 {\n    fn bar(&self) {}\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":"/checkout/src/test/ui/feature-gate-trivial_bounds.rs","byte_start":592,"byte_end":619,"line_start":20,"line_end":20,"column_start":1,"column_end":28,"is_primary":true,"text":[{"text":"enum E where i32: Foo { V } //~ ERROR","highlight_start":1,"highlight_end":28}],"label":"the trait `Foo` is not implemented for `i32`","suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"see issue #48214","code":null,"level":"help","spans":[],"children":[],"rendered":null},{"message":"add #![feature(trivial_bounds)] to the crate attributes to enable","code":null,"level":"help","spans":[],"children":[],"rendered":null}],"rendered":"error[E0277]: the trait bound `i32: Foo` is not satisfied\n  --> /checkout/src/test/ui/feature-gate-trivial_bounds.rs:20:1\n   |\nLL | enum E where i32: Foo { V } //~ ERROR\n   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `i32`\n   |\n   = help: see issue #48214\n   = help: add #![feature(trivial_bounds)] to the crate attributes to enable\n\n"}
[01:00:06] {"message":"the trait bound `i32: Foo` is not satisfied","code":{"code":"E0277","explanation":"\nYou tried to use a type which doesn't implement some trait in a place which\nexpected that trait. Erroneous 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\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\n// we implement the trait on the i32 type\nimpl Foo for i32 {\n    fn bar(&self) {}\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(Withouting 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\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\n// we implement the trait on the i32 type\nimpl Foo for i32 {\n    fn bar(&self) {}\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":"/checkout/src/test/ui/feature-gate-trivial_bounds.rs","byte_start":667,"byte_end":692,"line_start":24,"line_end":24,"column_start":1,"column_end":26,"is_primary":true,"text":[{"text":"trait T where i32: Foo {} //~ ERROR","highlight_start":1,"highlight_end":26}],"label":"the trait `Foo` is not implemented for `i32`","suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"see issue #48214","code":null,"level":"help","spans":[],"children":[],"rendered":null},{"message":"add #![feature(trivial_bounds)] to the crate attributes to enable","code":null,"level":"help","spans":[],"children":[],"rendered":null}],"rendered":"error[E0277]: the trait bound `i32: Foo` is not satisfied\n  --> /checkout/src/test/ui/feature-gate-trivial_bounds.rs:24:1\n   |\nLL | trait T where i32: Foo {} //~ ERROR\n   | ^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `i32`\n   |\n   = help: see issue #48214\n   = help: add #![feature(trivial_bounds)] to the crate attributes to enable\n\n"}
[01:00:06] {"message":"the trait bound `i32: Foo` is not satisfied","code":{"code":"E0277","explanation":"\nYou tried to use a type which doesn't implement some trait in a place which\nexpected that trait. Erroneous code example:\n\n```compile_fail,E0277\n// here we declar:"the trait bound `i32: Foo` is not satisfied","code":{"code":"E0277","explanation":"\nYou tried to use a type which doesn't implement some trait in a place which\nexpected that trait. Erroneous 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\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\n// we implement the trait on the i32 type\nimpl Foo for i32 {\n    fn bar(&self) {}\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":"/checkout/src/test/ui/feature-gate-trivial_bounds.rs","byte_start":803,"byte_end":953,"line_start":30,"line_end":36,"column_start":1,"column_end":2,"is_primary":true,"text":[{"text":"impl Foo for () where i32: Foo { //~ ERROR","highlight_start":1,"highlight_end":43},{"text":"    fn test(&self) {","highlight_start":1,"highlight_end":21},{"text":"        3i32.test();","highlight_start":1,"highlight_end":21},{"text":"        Foo::test(&4i32);","highlight_start":1,"highlight_end":26},{"text":"        generic_function(5i32);","highlight_start":1,"highlight_end":32},{"text":"    }","highlight_start":1,"highlight_end":6},{"text":"}","highlight_start":1,"highlight_end":2}],"label":"the trait `Foo` is not implemented for `i32`","suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"see issue #48214","code":null,"level":"help","spans":[],"children":[],"rendered":null},{"message":"add #![feature(trivial_bounds)] to the crate attributes to enable","code":null,"level":"help","spans":[],"children":[],"rendered":null}],"rendered":"error[E0277]: the trait bound `i32: Foo` is not satisfied\n  --> /checkout/src/test/ui/feature-gate-trivial_bounds.rs:30:1\n   |\nLL | / impl Foo for () where i32: Foo { //~ ERROR\nLL | |     fn test(&self) {\nLL | |         3i32.test();\nLL | |         Foo::test(&4i32);\nLL | |         generic_function(5i32);\nLL | |     }\nLL | | }\n   | |_^ the trait `Foo` is not implemented for `i32`\n   |\n   = help: see issue #48214\n   = help: add #![feature(trivial_bounds)] to the crate attributes to enable\n\n"}
[01:00:06] {"message":"the trait bound `i32: Foo` is not satisfied","code":{"code":"E0277","explanation":"\nYou tried to use a type which doesn't implement some trait in a place which\nexpected that trait. Erroneous 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\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\n// we implement the trait on the\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\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\n// we implement the trait on the i32 type\nimpl Foo for i32 {\n    fn bar(&self) {}\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":"/checkout/src/test/ui/feature-gate-trivial_bounds.rs","byte_start":1074,"byte_end":1170,"line_start":46,"line_end":48,"column_start":1,"column_end":2,"is_primary":true,"text":[{"text":"fn use_op(s: String) -> String where String: ::std::ops::Neg<Output=String> { //~ ERROR","highlight_start":1,"highlight_end":88},{"text":"    -s","highlight_start":1,"highlight_end":7},{"text":"}","highlight_start":1,"highlight_end":2}],"label":"the trait `std::ops::Neg` is not implemented for `std::string::String`","suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"see issue #48214","code":null,"level":"help","spans":[],"children":[],"rendered":null},{"message":"add #![feature(trivial_bounds)] to the crate attributes to enable","code":null,"level":"help","spans":[],"children":[],"rendered":null}],"rendered":"error[E0277]: the trait bound `std::string::String: std::ops::Neg` is not satisfied\n  --> /checkout/src/test/ui/feature-gate-trivial_bounds.rs:46:1\n   |\nLL | / fn use_op(s: String) -> String where String: ::std::ops::Neg<Output=String> { //~ ERROR\nLL | |     -s\nLL | | }\n   | |_^ the trait `std::ops::Neg` is not implemented for `std::string::String`\n   |\n   = help: see issue #482ition 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":"/checkout/src/test/ui/feature-gate-trivial_bounds.rs","byte_start":1172,"byte_end":1239,"line_start":50,"line_end":52,"column_start":1,"column_end":2,"is_primary":true,"text":[{"text":"fn use_for() where i32: Iterator { //~ ERROR","highlight_start":1,"highlight_end":45},{"text":"    for _ in 2i32 {}","highlight_start":1,"highlight_end":21},{"text":"}","highlight_start":1,"highlight_end":2}],"label":"`i32` is not an iterator; maybe try calling `.iter()` or a similar method","suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"the trait `std::iter::Iterator` is not implemented for `i32`","code":null,"level":"help","spans":[],"children":[],"rendered":null},{"message":"see issue #48214","code":null,"level":"help","spans":[],"children":[],"renden\n// we implement the trait on the i32 type\nimpl Foo for i32 {\n    fn bar(&self) {}\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":"/checkout/src/test/ui/feature-gate-trivial_bounds.rs","byte_start":1309,"byte_end":1351,"line_start":62,"line_end":62,"column_start":1,"column_end":43,"is_primary":true,"text":[{"text":"struct TwoStrs(str, str) where str: Sized; //~ ERROR","highlight_start":1,"highlight_end":43}],"label":"`str` does not have a constant size known at compile-time","suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"the trait `std::marker::Sized` is not implemented for `str`","code":null,"level":"help","spans":[],"children":[],"rendered":null},{"message":"see issue #48214","code":null,"level":"help","spans":[],"children":[],"rendered":null},{"message":"add #![feature(trivial_bounds)] to the crate attributes to enable","code":null,"level":"help","spans":[],"children":[],"rendered":null}],"rendered":"error[E0277]: the trait bound `str: std::marker::Sized` is not satisfied\n  --> /checkout/src/test/ui/feature-gate-trivial_bounds.rs:62:1\n   |\nLL | struct TwoStrs(str, str) where str: Sized; //~ ERROR\n   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `str` does not have a constant size known at compile-time\n   |\n   = help: the trait `std::marker::Sized` is not implemented for `str`\n   = help: see issue #48214\n   = help: add #![feature(trivial_bounds)] to the crate attributes to enable\n\n"}
[01:00:06] {"message":"the trait bound `A + 'static: std::marker::Sized` is not satisfied in `Dst<A + 'static>`","code":{"code":"E0277","explanation":"\nYou tried to use a type which doesn't implement some trait in a place which\nexpected that trait. Erroneous 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\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\n// we implement the trait on the i32 type\nimpl Foo for i32 {\n    fn bar(&self) {}\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 fn unsized_local() where Dst<A>: Sized { //~ ERROR\nLL | |     let x: Dst<A> = *(Box::new(Dst { x: 1 }) as Box<Dst<A>>);\nLL | | }\n   | |_^ `A + 'static` does not have a constant size known at compile-time\n   |\n   = help: within `Dst<A + 'static>`, the trait `std::marker::Sized` is not implemented for `A + 'static`\n   = note: required because it appears within the type `Dst<A + 'static>`\n   = help: see issue #48214\n   = help: add #![feature(trivial_bounds)] to the crate attributes to enable\n\n"}
[01:00:06] {"message":"the trait bound `str: std::marker::Sized` is not satisfied","code":{"code":"E0277","explanation":"\nYou tried to use a type which doesn't implement some trait in a place which\nexpected that trait. Erroneous 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\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\n// we implement the trait on the i32 type\nimpl Foo for i32 {\n    fn bar(&self) {}\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":"/checkout/src/test/ui/feature-gate-trivial_bounds.rs","byte_start":1480,"byte_end":1575,"line_start":69,"line_end":71,"column_start":1,"column_end":2,"is_primary":true,"text":[{"text":"fn return_str() -> str where str: Sized { //~ ERROR","highlight_start":1,"highlight_end":52},{"text":"    *\"Sized\".to_string().into_boxed_str()","highlight_start":1,"highlight_end":42},{"text":it code: 101
[01:00:06] 
[01:00:06] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[01:00:06] Build completed unsuccessfully in 0:03:20
[01:00:06] Build completed unsuccessfully in 0:03:20
[01:00:06] Makefile:58: recipe for target 'check' failed
[01:00:06] make: *** [check] Error 1

The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:0d8d3720
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[rust-highfive]

The job x86_64-gnu-llvm-3.9 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[01:17:28] ..............................................................................................i.....
[01:17:32] ....................................................................................................
[01:17:39] ....................................................................................................
[01:17:45] ....................................................................................................
[01:17:52] ................F...................................................................................
[01:18:08] ....................................................................................................
[01:18:14] ...i................................................................................................
[01:18:21] ..i..ii.............................................................................................
[01:18:30] ....................................................................................................
---
[01:19:10] failures:
[01:19:10] 
[01:19:10] ---- [compile-fail] compile-fail/issue-36839.rs stdout ----
[01:19:10] 
[01:19:10] error: /checkout/src/test/compile-fail/issue-36839.rs:24: unexpected error: '24:5: 26:6: the trait bound `(): Foo` is not satisfied [E0277]'
[01:19:10] 
[01:19:10] error: /checkout/src/test/compile-fail/issue-36839.rs:30: expected error not found: compilation successful
[01:19:10] 
[01:19:10] error: 1 unexpected errors found, 1 expected errors not found
[01:19:10] status: exit code: 101
[01:19:10] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/compile-fail/issue-36839.rs" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/compile-fail/issue-36839/a" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/compile-fail/issue-36839/auxiliary" "-A" "unused"
[01:19:10] unexpected errors (from JSON output): [
[01:19:10]     Error {
[01:19:10]         line_num: 24,
[01:19:10]         kind: Some(
[01:19:10]         ),
[01:19:10]         ),
[01:19:10]         msg: "24:5: 26:6: the trait bound `(): Foo` is not satisfied [E0277]"
[01:19:10] ]
[01:19:10] 
[01:19:10] not found errors (from test file): [
[01:19:10]     Error {
[01:19:10]     Error {
[01:19:10]         line_num: 30,
[01:19:10]         kind: Some(
[01:19:10]             Error
[01:19:10]         ),
[01:19:10]         msg: "compilation successful"
[01:19:10] ]
[01:19:10] 
[01:19:10] thread '[compile-fail] compile-fail/issue-36839.rs' panicked at 'explicit panic', tools/compiletest/src/runtest.rs:1283:13
[01:19:10] note: Run with `RUST_BACKTRACE=1` for a backtrace.
---
[01:19:10] 
[01:19:10] thread 'main' panicked at 'Some tests failed', tools/compiletest/src/main.rs:498:22
[01:19:10] 
[01:19:10] 
[01:19:10] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/compiletest" "--compile-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib" "--run-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib" "--rustc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "--src-base" "/checkout/src/test/compile-fail" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/compile-fail" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--mode" "compile-fail" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/usr/lib/llvm-3.9/bin/FileCheck" "--host-rustcflags" "-Crpath -O -Zunstable-options " "--target-rustcflags" "-Crpath -O -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--docck-python" "/usr/bin/python2.7" "--lldb-python" "/usr/bin/python2.7" "--gdb" "/usr/bin/gdb" "--quiet" "--llvm-version" "3.9.1\n" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--llvm-components" "" "--llvm-cxxflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"
[01:19:10] 
[01:19:10] 
[01:19:10] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[01:19:10] Build completed unsuccessfully in 0:20:03
[01:19:10] Build completed unsuccessfully in 0:20:03
[01:19:10] Makefile:58: recipe for target 'check' failed
[01:19:10] make: *** [check] Error 1

The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:0f7d4b79
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[TimNN]

Triage ping, @nikomatsakis, this PR is waiting for your review.

[emilyalbini]

Ping from triage! This PR needs a review, can @nikomatsakis or someone else from @rust-lang/compiler review this?

[nikomatsakis]

I will review this one, but I haven't gotten to it yet.

[nikomatsakis]

Ugh. But makes sense. Chalk can't come soon enough!

[nikomatsakis]

Not sure what this FIXME is suggesting -- you did add one in ParamCandidate case, which seems like the case where it would be relevant..?

[matthewjasper]

I just forgot to remove the comment

[Eijebong]

I confirm that this makes diesel master compile again 🎉

[nikomatsakis]

@bors r+

[bors]

📌 Commit a1bddcf has been approved by nikomatsakis

[bors]

🌲 The tree is currently closed for pull requests below priority 1, this pull request will be tested once the tree is reopened

[nikomatsakis]

@bors r- -- oops, had a few questions

[nikomatsakis]

In particular, I wanted to know what was up with that FIXME -- maybe we should just remove it? I suspect it is outdated.

[lnicola]

@nikomatsakis #51042 (comment)

[nikomatsakis]

Oh, I missed that =)

@bors r+ p=1 -- fixes regressions

[bors]

📌 Commit a1bddcf has been approved by nikomatsakis

[bors]

⌛ Testing commit a1bddcf with merge 1c5626f...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: nikomatsakis
Pushing 1c5626f to master...