[INFO] fetching crate vecdeque-stableix 1.1.1... [INFO] checking vecdeque-stableix-1.1.1 against try#4d98531622e1718ae0bc3c7a1ab9cd8938428452+rustflags=-Dtail_expr_drop_order for pr-129604 [INFO] extracting crate vecdeque-stableix 1.1.1 into /workspace/builds/worker-5-tc2/source [INFO] validating manifest of crates.io crate vecdeque-stableix 1.1.1 on toolchain 4d98531622e1718ae0bc3c7a1ab9cd8938428452 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4d98531622e1718ae0bc3c7a1ab9cd8938428452" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking crates.io crate vecdeque-stableix 1.1.1 [INFO] finished tweaking crates.io crate vecdeque-stableix 1.1.1 [INFO] tweaked toml for crates.io crate vecdeque-stableix 1.1.1 written to /workspace/builds/worker-5-tc2/source/Cargo.toml [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4d98531622e1718ae0bc3c7a1ab9cd8938428452" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] [stderr] Updating crates.io index [INFO] [stderr] Locking 3 packages to latest compatible versions [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4d98531622e1718ae0bc3c7a1ab9cd8938428452" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+4d98531622e1718ae0bc3c7a1ab9cd8938428452" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 38481174bb35f98f0a4e9a90253f624d0ec3c56fa8429403605f1595adc40404 [INFO] running `Command { std: "docker" "start" "-a" "38481174bb35f98f0a4e9a90253f624d0ec3c56fa8429403605f1595adc40404", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "38481174bb35f98f0a4e9a90253f624d0ec3c56fa8429403605f1595adc40404", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "38481174bb35f98f0a4e9a90253f624d0ec3c56fa8429403605f1595adc40404", kill_on_drop: false }` [INFO] [stdout] 38481174bb35f98f0a4e9a90253f624d0ec3c56fa8429403605f1595adc40404 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid -Dtail_expr_drop_order" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+4d98531622e1718ae0bc3c7a1ab9cd8938428452" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 0f59611afc20c52a221a78b4175f9c0ee22d64e30ca5cdf70f32858aacb5ba1c [INFO] running `Command { std: "docker" "start" "-a" "0f59611afc20c52a221a78b4175f9c0ee22d64e30ca5cdf70f32858aacb5ba1c", kill_on_drop: false }` [INFO] [stderr] Compiling num-traits v0.2.19 [INFO] [stderr] Checking vecdeque-stableix v1.1.1 (/opt/rustwide/workdir) [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:142:5 [INFO] [stdout] | [INFO] [stdout] 141 | fn index_input(&self, input: Self) -> Option { [INFO] [stdout] | ----------- these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 142 | input.checked_sub(&self)?.try_into().ok() [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] = note: requested on the command line with `-D tail-expr-drop-order` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:165:17 [INFO] [stdout] | [INFO] [stdout] 163 | fn from_iter(iter: X) -> Self where X: IntoIterator { [INFO] [stdout] | ------- these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 164 | Deque { [INFO] [stdout] 165 | advanced: I::zero(), [INFO] [stdout] | ^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:166:10 [INFO] [stdout] | [INFO] [stdout] 163 | fn from_iter(iter: X) -> Self where X: IntoIterator { [INFO] [stdout] | ------- these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] ... [INFO] [stdout] 166 | v: as FromIterator>::from_iter(iter) [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:185:14 [INFO] [stdout] | [INFO] [stdout] 183 | let i = self.front.clone(); [INFO] [stdout] | - these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 184 | self.front.try_increment().unwrap(); [INFO] [stdout] 185 | Some((i,t)) [INFO] [stdout] | ^^^^^ [INFO] [stdout] ... [INFO] [stdout] 219 | define_iter!{ Iter get iter } [INFO] [stdout] | ----------------------------- in this macro invocation [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] = note: this error originates in the macro `define_iter` (in Nightly builds, run with -Z macro-backtrace for more info) [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:192:14 [INFO] [stdout] | [INFO] [stdout] 191 | let i = self.front.clone().index_output(self.vd.len()).unwrap(); [INFO] [stdout] | - these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 192 | Some((i,t)) [INFO] [stdout] | ^^^^^ [INFO] [stdout] ... [INFO] [stdout] 219 | define_iter!{ Iter get iter } [INFO] [stdout] | ----------------------------- in this macro invocation [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] = note: this error originates in the macro `define_iter` (in Nightly builds, run with -Z macro-backtrace for more info) [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:185:14 [INFO] [stdout] | [INFO] [stdout] 183 | let i = self.front.clone(); [INFO] [stdout] | - these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 184 | self.front.try_increment().unwrap(); [INFO] [stdout] 185 | Some((i,t)) [INFO] [stdout] | ^^^^^ [INFO] [stdout] ... [INFO] [stdout] 227 | define_iter!{ IterMut get_mut iter_mut mut } [INFO] [stdout] | -------------------------------------------- in this macro invocation [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] = note: this error originates in the macro `define_iter` (in Nightly builds, run with -Z macro-backtrace for more info) [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:192:14 [INFO] [stdout] | [INFO] [stdout] 191 | let i = self.front.clone().index_output(self.vd.len()).unwrap(); [INFO] [stdout] | - these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 192 | Some((i,t)) [INFO] [stdout] | ^^^^^ [INFO] [stdout] ... [INFO] [stdout] 227 | define_iter!{ IterMut get_mut iter_mut mut } [INFO] [stdout] | -------------------------------------------- in this macro invocation [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] = note: this error originates in the macro `define_iter` (in Nightly builds, run with -Z macro-backtrace for more info) [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:253:10 [INFO] [stdout] | [INFO] [stdout] 252 | let t = self.dq.pop_back()?; [INFO] [stdout] | - these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 253 | Some((self.dq.end_index(), t)) [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^ these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:297:5 [INFO] [stdout] | [INFO] [stdout] 293 | pub fn push_front(&mut self, e : T) -> I { [INFO] [stdout] | ----- these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] ... [INFO] [stdout] 297 | self.advanced.index_output(p).unwrap() [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:303:5 [INFO] [stdout] | [INFO] [stdout] 300 | pub fn push_back(&mut self, e : T) -> I { [INFO] [stdout] | ----- these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] ... [INFO] [stdout] 303 | self.advanced.index_output(p).unwrap() [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: aborting due to 10 previous errors [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] error: could not compile `vecdeque-stableix` (lib) due to 11 previous errors [INFO] [stderr] warning: build failed, waiting for other jobs to finish... [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:142:5 [INFO] [stdout] | [INFO] [stdout] 141 | fn index_input(&self, input: Self) -> Option { [INFO] [stdout] | ----------- these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 142 | input.checked_sub(&self)?.try_into().ok() [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] = note: requested on the command line with `-D tail-expr-drop-order` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:165:17 [INFO] [stdout] | [INFO] [stdout] 163 | fn from_iter(iter: X) -> Self where X: IntoIterator { [INFO] [stdout] | ------- these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 164 | Deque { [INFO] [stdout] 165 | advanced: I::zero(), [INFO] [stdout] | ^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:166:10 [INFO] [stdout] | [INFO] [stdout] 163 | fn from_iter(iter: X) -> Self where X: IntoIterator { [INFO] [stdout] | ------- these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] ... [INFO] [stdout] 166 | v: as FromIterator>::from_iter(iter) [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:185:14 [INFO] [stdout] | [INFO] [stdout] 183 | let i = self.front.clone(); [INFO] [stdout] | - these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 184 | self.front.try_increment().unwrap(); [INFO] [stdout] 185 | Some((i,t)) [INFO] [stdout] | ^^^^^ [INFO] [stdout] ... [INFO] [stdout] 219 | define_iter!{ Iter get iter } [INFO] [stdout] | ----------------------------- in this macro invocation [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] = note: this error originates in the macro `define_iter` (in Nightly builds, run with -Z macro-backtrace for more info) [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:192:14 [INFO] [stdout] | [INFO] [stdout] 191 | let i = self.front.clone().index_output(self.vd.len()).unwrap(); [INFO] [stdout] | - these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 192 | Some((i,t)) [INFO] [stdout] | ^^^^^ [INFO] [stdout] ... [INFO] [stdout] 219 | define_iter!{ Iter get iter } [INFO] [stdout] | ----------------------------- in this macro invocation [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] = note: this error originates in the macro `define_iter` (in Nightly builds, run with -Z macro-backtrace for more info) [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:185:14 [INFO] [stdout] | [INFO] [stdout] 183 | let i = self.front.clone(); [INFO] [stdout] | - these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 184 | self.front.try_increment().unwrap(); [INFO] [stdout] 185 | Some((i,t)) [INFO] [stdout] | ^^^^^ [INFO] [stdout] ... [INFO] [stdout] 227 | define_iter!{ IterMut get_mut iter_mut mut } [INFO] [stdout] | -------------------------------------------- in this macro invocation [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] = note: this error originates in the macro `define_iter` (in Nightly builds, run with -Z macro-backtrace for more info) [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:192:14 [INFO] [stdout] | [INFO] [stdout] 191 | let i = self.front.clone().index_output(self.vd.len()).unwrap(); [INFO] [stdout] | - these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 192 | Some((i,t)) [INFO] [stdout] | ^^^^^ [INFO] [stdout] ... [INFO] [stdout] 227 | define_iter!{ IterMut get_mut iter_mut mut } [INFO] [stdout] | -------------------------------------------- in this macro invocation [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] = note: this error originates in the macro `define_iter` (in Nightly builds, run with -Z macro-backtrace for more info) [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:253:10 [INFO] [stdout] | [INFO] [stdout] 252 | let t = self.dq.pop_back()?; [INFO] [stdout] | - these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] 253 | Some((self.dq.end_index(), t)) [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^ these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] error: could not compile `vecdeque-stableix` (lib test) due to 11 previous errors [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:297:5 [INFO] [stdout] | [INFO] [stdout] 293 | pub fn push_front(&mut self, e : T) -> I { [INFO] [stdout] | ----- these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] ... [INFO] [stdout] 297 | self.advanced.index_output(p).unwrap() [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021 [INFO] [stdout] --> src/lib.rs:303:5 [INFO] [stdout] | [INFO] [stdout] 300 | pub fn push_back(&mut self, e : T) -> I { [INFO] [stdout] | ----- these values have significant drop implementation and will observe changes in drop order under Edition 2024 [INFO] [stdout] ... [INFO] [stdout] 303 | self.advanced.index_output(p).unwrap() [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this changes meaning in Rust 2024 [INFO] [stdout] = note: for more information, see issue #123739 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: aborting due to 10 previous errors [INFO] [stdout] [INFO] [stdout] [INFO] running `Command { std: "docker" "inspect" "0f59611afc20c52a221a78b4175f9c0ee22d64e30ca5cdf70f32858aacb5ba1c", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "0f59611afc20c52a221a78b4175f9c0ee22d64e30ca5cdf70f32858aacb5ba1c", kill_on_drop: false }` [INFO] [stdout] 0f59611afc20c52a221a78b4175f9c0ee22d64e30ca5cdf70f32858aacb5ba1c