Add #[must_use] to From::from and Into::into #89770

jkugelman · 2021-10-11T14:22:16Z

Risk of churn: High
Magic 8-Ball says: Outlook not so good

I figured I'd put this out there. If we don't do it now maybe we save it for a rainy day.

Parent issue: #89692

r? @joshtriplett

joshtriplett · 2021-10-11T18:49:10Z

@bors r+

bors · 2021-10-11T18:49:11Z

📌 Commit 3d1996a has been approved by joshtriplett

jkugelman · 2021-10-11T19:01:28Z

@joshtriplett Should I go look at all the other traits like Eq and Clone and whatnot? Clippy ignores trait methods so they're not on my list.

Edit: Bad examples, though. They're already must-use.

…=joshtriplett Add #[must_use] to From::from and Into::into Risk of churn: **High** Magic 8-Ball says: **Outlook not so good** I figured I'd put this out there. If we don't do it now maybe we save it for a rainy day. Parent issue: rust-lang#89692 r? `@joshtriplett`

matthiaskrgr · 2021-10-11T21:43:44Z

Rollup failure in #89783 , I think it is this pr, but not 100% sure

#89783 (comment)

---- compile_test stdout ----

error: failed to compile fixed code
status: exit status: 1
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/clippy-driver" "tests/ui/cast_lossless_float.fixed" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/test" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/test/cast_lossless_float.stage-id" "--emit=metadata" "-Dwarnings" "-Zui-testing" "-L" "dependency=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps" "-L" "dependency=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/release/deps" "--extern" "regex=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libregex-392b40a2759b0504.rlib" "--extern" "serde_derive=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/release/deps/libserde_derive-8bd56d0234290b82.so" "--extern" "serde=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libserde-89222f6e0d369b36.rlib" "--extern" "if_chain=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libif_chain-b3e76e8f62643cc6.rlib" "--extern" "clippy_utils=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libclippy_utils-bc2b0c8a9dcb9fb3.rlib" "--extern" "derive_new=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/release/deps/libderive_new-ea1db0c41efed0d6.so" "--extern" "itertools=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libitertools-b0f19a5fad83a10b.rlib" "--extern" "syn=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libsyn-2c42e7af51424ce5.rlib" "--extern" "quote=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libquote-c6bd037ba33baa25.rlib" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/test/cast_lossless_float.stage-id.aux"
------------------------------------------

------------------------------------------
stderr:
stderr:
------------------------------------------
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":223,"byte_end":237,"line_start":9,"line_end":9,"column_start":5,"column_end":19,"is_primary":true,"text":[{"text":"    f32::from(x0);","highlight_start":5,"highlight_end":19}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"`-D unused-must-use` implied by `-D warnings`","code":null,"level":"note","spans":[],"children":[],"rendered":null}],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:9:5\n   |\nLL |     f32::from(x0);\n   |     ^^^^^^^^^^^^^^\n   |\n   = note: `-D unused-must-use` implied by `-D warnings`\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":242,"byte_end":256,"line_start":10,"line_end":10,"column_start":5,"column_end":19,"is_primary":true,"text":[{"text":"    f64::from(x0);","highlight_start":5,"highlight_end":19}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:10:5\n   |\nLL |     f64::from(x0);\n   |     ^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":279,"byte_end":293,"line_start":12,"line_end":12,"column_start":5,"column_end":19,"is_primary":true,"text":[{"text":"    f32::from(x1);","highlight_start":5,"highlight_end":19}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:12:5\n   |\nLL |     f32::from(x1);\n   |     ^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":298,"byte_end":312,"line_start":13,"line_end":13,"column_start":5,"column_end":19,"is_primary":true,"text":[{"text":"    f64::from(x1);","highlight_start":5,"highlight_end":19}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:13:5\n   |\nLL |     f64::from(x1);\n   |     ^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":336,"byte_end":350,"line_start":15,"line_end":15,"column_start":5,"column_end":19,"is_primary":true,"text":[{"text":"    f32::from(x2);","highlight_start":5,"highlight_end":19}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:15:5\n   |\nLL |     f32::from(x2);\n   |     ^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":355,"byte_end":369,"line_start":16,"line_end":16,"column_start":5,"column_end":19,"is_primary":true,"text":[{"text":"    f64::from(x2);","highlight_start":5,"highlight_end":19}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:16:5\n   |\nLL |     f64::from(x2);\n   |     ^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":393,"byte_end":407,"line_start":18,"line_end":18,"column_start":5,"column_end":19,"is_primary":true,"text":[{"text":"    f32::from(x3);","highlight_start":5,"highlight_end":19}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:18:5\n   |\nLL |     f32::from(x3);\n   |     ^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":412,"byte_end":426,"line_start":19,"line_end":19,"column_start":5,"column_end":19,"is_primary":true,"text":[{"text":"    f64::from(x3);","highlight_start":5,"highlight_end":19}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:19:5\n   |\nLL |     f64::from(x3);\n   |     ^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":450,"byte_end":464,"line_start":21,"line_end":21,"column_start":5,"column_end":19,"is_primary":true,"text":[{"text":"    f64::from(x4);","highlight_start":5,"highlight_end":19}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:21:5\n   |\nLL |     f64::from(x4);\n   |     ^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":488,"byte_end":502,"line_start":23,"line_end":23,"column_start":5,"column_end":19,"is_primary":true,"text":[{"text":"    f64::from(x5);","highlight_start":5,"highlight_end":19}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:23:5\n   |\nLL |     f64::from(x5);\n   |     ^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_float.fixed","byte_start":557,"byte_end":575,"line_start":26,"line_end":26,"column_start":5,"column_end":23,"is_primary":true,"text":[{"text":"    f64::from(1.0f32);","highlight_start":5,"highlight_end":23}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_float.fixed:26:5\n   |\nLL |     f64::from(1.0f32);\n   |     ^^^^^^^^^^^^^^^^^^\n\n"}

------------------------------------------



error: failed to compile fixed code
status: exit status: 1
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/clippy-driver" "tests/ui/cast_lossless_integer.fixed" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/test" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/test/cast_lossless_integer.stage-id" "--emit=metadata" "-Dwarnings" "-Zui-testing" "-L" "dependency=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps" "-L" "dependency=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/release/deps" "--extern" "regex=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libregex-392b40a2759b0504.rlib" "--extern" "serde_derive=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/release/deps/libserde_derive-8bd56d0234290b82.so" "--extern" "serde=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libserde-89222f6e0d369b36.rlib" "--extern" "if_chain=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libif_chain-b3e76e8f62643cc6.rlib" "--extern" "clippy_utils=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libclippy_utils-bc2b0c8a9dcb9fb3.rlib" "--extern" "derive_new=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/release/deps/libderive_new-ea1db0c41efed0d6.so" "--extern" "itertools=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libitertools-b0f19a5fad83a10b.rlib" "--extern" "syn=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libsyn-2c42e7af51424ce5.rlib" "--extern" "quote=/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/libquote-c6bd037ba33baa25.rlib" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/test/cast_lossless_integer.stage-id.aux"
------------------------------------------

------------------------------------------
error: test failed, to rerun pass '--test compile-test'
error: test failed, to rerun pass '--test compile-test'
stderr:
------------------------------------------
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":198,"byte_end":213,"line_start":8,"line_end":8,"column_start":5,"column_end":20,"is_primary":true,"text":[{"text":"    i16::from(1i8);","highlight_start":5,"highlight_end":20}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"`-D unused-must-use` implied by `-D warnings`","code":null,"level":"note","spans":[],"children":[],"rendered":null}],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:8:5\n   |\nLL |     i16::from(1i8);\n   |     ^^^^^^^^^^^^^^^\n   |\n   = note: `-D unused-must-use` implied by `-D warnings`\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":218,"byte_end":233,"line_start":9,"line_end":9,"column_start":5,"column_end":20,"is_primary":true,"text":[{"text":"    i32::from(1i8);","highlight_start":5,"highlight_end":20}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:9:5\n   |\nLL |     i32::from(1i8);\n   |     ^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":238,"byte_end":253,"line_start":10,"line_end":10,"column_start":5,"column_end":20,"is_primary":true,"text":[{"text":"    i64::from(1i8);","highlight_start":5,"highlight_end":20}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:10:5\n   |\nLL |     i64::from(1i8);\n   |     ^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":258,"byte_end":273,"line_start":11,"line_end":11,"column_start":5,"column_end":20,"is_primary":true,"text":[{"text":"    i16::from(1u8);","highlight_start":5,"highlight_end":20}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:11:5\n   |\nLL |     i16::from(1u8);\n   |     ^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":278,"byte_end":293,"line_start":12,"line_end":12,"column_start":5,"column_end":20,"is_primary":true,"text":[{"text":"    i32::from(1u8);","highlight_start":5,"highlight_end":20}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:12:5\n   |\nLL |     i32::from(1u8);\n   |     ^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":298,"byte_end":313,"line_start":13,"line_end":13,"column_start":5,"column_end":20,"is_primary":true,"text":[{"text":"    i64::from(1u8);","highlight_start":5,"highlight_end":20}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:13:5\n   |\nLL |     i64::from(1u8);\n   |     ^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":318,"byte_end":333,"line_start":14,"line_end":14,"column_start":5,"column_end":20,"is_primary":true,"text":[{"text":"    u16::from(1u8);","highlight_start":5,"highlight_end":20}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:14:5\n   |\nLL |     u16::from(1u8);\n   |     ^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":338,"byte_end":353,"line_start":15,"line_end":15,"column_start":5,"column_end":20,"is_primary":true,"text":[{"text":"    u32::from(1u8);","highlight_start":5,"highlight_end":20}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:15:5\n   |\nLL |     u32::from(1u8);\n   |     ^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":358,"byte_end":373,"line_start":16,"line_end":16,"column_start":5,"column_end":20,"is_primary":true,"text":[{"text":"    u64::from(1u8);","highlight_start":5,"highlight_end":20}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:16:5\n   |\nLL |     u64::from(1u8);\n   |     ^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":378,"byte_end":394,"line_start":17,"line_end":17,"column_start":5,"column_end":21,"is_primary":true,"text":[{"text":"    i32::from(1i16);","highlight_start":5,"highlight_end":21}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:17:5\n   |\nLL |     i32::from(1i16);\n   |     ^^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":399,"byte_end":415,"line_start":18,"line_end":18,"column_start":5,"column_end":21,"is_primary":true,"text":[{"text":"    i64::from(1i16);","highlight_start":5,"highlight_end":21}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:18:5\n   |\nLL |     i64::from(1i16);\n   |     ^^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":420,"byte_end":436,"line_start":19,"line_end":19,"column_start":5,"column_end":21,"is_primary":true,"text":[{"text":"    i32::from(1u16);","highlight_start":5,"highlight_end":21}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:19:5\n   |\nLL |     i32::from(1u16);\n   |     ^^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":441,"byte_end":457,"line_start":20,"line_end":20,"column_start":5,"column_end":21,"is_primary":true,"text":[{"text":"    i64::from(1u16);","highlight_start":5,"highlight_end":21}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:20:5\n   |\nLL |     i64::from(1u16);\n   |     ^^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":462,"byte_end":478,"line_start":21,"line_end":21,"column_start":5,"column_end":21,"is_primary":true,"text":[{"text":"    u32::from(1u16);","highlight_start":5,"highlight_end":21}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:21:5\n   |\nLL |     u32::from(1u16);\n   |     ^^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":483,"byte_end":499,"line_start":22,"line_end":22,"column_start":5,"column_end":21,"is_primary":true,"text":[{"text":"    u64::from(1u16);","highlight_start":5,"highlight_end":21}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:22:5\n   |\nLL |     u64::from(1u16);\n   |     ^^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":504,"byte_end":520,"line_start":23,"line_end":23,"column_start":5,"column_end":21,"is_primary":true,"text":[{"text":"    i64::from(1i32);","highlight_start":5,"highlight_end":21}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:23:5\n   |\nLL |     i64::from(1i32);\n   |     ^^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":525,"byte_end":541,"line_start":24,"line_end":24,"column_start":5,"column_end":21,"is_primary":true,"text":[{"text":"    i64::from(1u32);","highlight_start":5,"highlight_end":21}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:24:5\n   |\nLL |     i64::from(1u32);\n   |     ^^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":546,"byte_end":562,"line_start":25,"line_end":25,"column_start":5,"column_end":21,"is_primary":true,"text":[{"text":"    u64::from(1u32);","highlight_start":5,"highlight_end":21}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:25:5\n   |\nLL |     u64::from(1u32);\n   |     ^^^^^^^^^^^^^^^^\n\n"}
{"message":"unused return value of `std::convert::From::from` that must be used","code":{"code":"unused_must_use","explanation":null},"level":"error","spans":[{"file_name":"tests/ui/cast_lossless_integer.fixed","byte_start":617,"byte_end":638,"line_start":28,"line_end":28,"column_start":5,"column_end":26,"is_primary":true,"text":[{"text":"    u16::from(1u8 + 1u8);","highlight_start":5,"highlight_end":26}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: unused return value of `std::convert::From::from` that must be used\n  --> tests/ui/cast_lossless_integer.fixed:28:5\n   |\nLL |     u16::from(1u8 + 1u8);\n   |     ^^^^^^^^^^^^^^^^^^^^^\n\n"}

------------------------------------------

thread 'compile_test' panicked at 'Some tests failed', /cargo/registry/src/github.com-1ecc6299db9ec823/compiletest_rs-0.7.0/src/lib.rs:105:22

jkugelman · 2021-10-11T21:47:59Z

Yes, it definitely is.

What's the process here? I'll fix the test(s) and re-push. Do I need to do anything else?

Any tips how I can verify that this is fixed for sure? This is the first time a change of mine has passed CI but failed in the rollup stage.

matthiaskrgr · 2021-10-11T21:56:17Z

iirc ./x.py test src/tools/clippy is the command to run clippy tests within the rustc repo.
The clippy sources are inside the repo so you can edit the test files or bless the output files to make sure the tests pass.
Don't worry about the ci failure, things like that just happen :)

jkugelman · 2021-10-11T22:11:09Z

Clippy tests fixed.

joshtriplett · 2021-10-12T04:17:16Z

@bors r+

bors · 2021-10-12T04:17:17Z

📌 Commit f9692b5 has been approved by joshtriplett

…=joshtriplett Add #[must_use] to From::from and Into::into Risk of churn: **High** Magic 8-Ball says: **Outlook not so good** I figured I'd put this out there. If we don't do it now maybe we save it for a rainy day. Parent issue: rust-lang#89692 r? `@joshtriplett`

bors · 2021-10-12T09:43:40Z

⌛ Testing commit f9692b5 with merge 9475e60...

bors · 2021-10-12T12:40:52Z

☀️ Test successful - checks-actions
Approved by: joshtriplett
Pushing 9475e60 to master...

rust-timer · 2021-10-12T14:09:47Z

Finished benchmarking commit (9475e60): comparison url.

Summary: This benchmark run did not return any relevant changes.

If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.

@rustbot label: -perf-regression

…oshtriplett Add #[must_use] to From::from and Into::into Risk of churn: **High** Magic 8-Ball says: **Outlook not so good** I figured I'd put this out there. If we don't do it now maybe we save it for a rainy day. Parent issue: rust-lang#89692 r? `@joshtriplett`

rust-highfive assigned joshtriplett Oct 11, 2021

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Oct 11, 2021

jkugelman mentioned this pull request Oct 11, 2021

Tracking issue for adding #[must_use] annotations throughout the standard library #89692

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jkugelman force-pushed the must-use-from-and-into branch from 602cdac to 1d5f287 Compare October 11, 2021 14:40

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jkugelman force-pushed the must-use-from-and-into branch from 1d5f287 to 3d1996a Compare October 11, 2021 16:02

joshtriplett added the relnotes Marks issues that should be documented in the release notes of the next release. label Oct 11, 2021

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Oct 11, 2021

matthiaskrgr mentioned this pull request Oct 11, 2021

Rollup of 10 pull requests #89783

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Add #[must_use] to From::from and Into::into

f9692b5

jkugelman force-pushed the must-use-from-and-into branch from 3d1996a to f9692b5 Compare October 11, 2021 22:10

the8472 added the T-libs Relevant to the library team, which will review and decide on the PR/issue. label Oct 11, 2021

matthiaskrgr mentioned this pull request Oct 12, 2021

Rollup of 8 pull requests #89801

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bors added the merged-by-bors This PR was explicitly merged by bors. label Oct 12, 2021

bors merged commit 9475e60 into rust-lang:master Oct 12, 2021

rustbot added this to the 1.57.0 milestone Oct 12, 2021

jkugelman deleted the must-use-from-and-into branch October 12, 2021 12:50

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Add #[must_use] to From::from and Into::into #89770

Add #[must_use] to From::from and Into::into #89770

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Add #[must_use] to From::from and Into::into #89770

Add #[must_use] to From::from and Into::into #89770

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edited