Fix 'cargo build'

CONTRIBUTING.md

@@ -14,9 +14,10 @@ Each segment ends with an exercise. Exercises are typically structured as an
 `exercise.rs` containing the problem and solution. This is referenced from
 `exercise.md` and `solution.md`, using `{{#include exercise.rs:anchor_name}}` to
 match ANCHOR comments in the `exercise.rs` file. Each segment also has a
-`Cargo.toml` file containing a `[[bin]]` section referring to `exercise.rs`, and
-that Cargo package is referenced from the workspace the root `Cargo.toml`. The
-result is that `exercise.rs` is built and tested by `cargo test`.
+`Cargo.toml` file containing a `[[bin]]` or `[lib]` section referring to
+`exercise.rs`, and that Cargo package is referenced from the workspace the root
+`Cargo.toml`. The result is that `exercise.rs` is built and tested by
+`cargo test`.
 
 For segments on day 1, exercises should use `fn main() { .. }` and `println!`,
 with students visually verifying the correct output. On subsequent days, prefer

src/borrowing/Cargo.toml

@@ -4,6 +4,6 @@ version = "0.1.0"
 edition = "2021"
 publish = false
 
-[[bin]]
+[lib]
 name = "borrowing"
 path = "../../third_party/rust-on-exercism/health-statistics.rs"

src/error-handling/Cargo.toml

@@ -8,6 +8,6 @@ publish = false
 anyhow = "*"
 thiserror = "*"
 
-[[bin]]
+[lib]
 name = "parser"
 path = "exercise.rs"

src/generics/Cargo.toml

@@ -4,6 +4,6 @@ version = "0.1.0"
 edition = "2021"
 publish = false
 
-[[bin]]
+[lib]
 name = "generics"
 path = "exercise.rs"

src/generics/exercise.md

@@ -7,7 +7,7 @@ minutes: 10
 In this short exercise, you will implement a generic `min` function that
 determines the minimum of two values, using the [`Ord`] trait.
 
-```rust,compile_fail,editable
+```rust,editable
 use std::cmp::Ordering;
 
 // TODO: implement the `min` function used in the tests.

src/generics/exercise.rs

@@ -11,6 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+#![allow(dead_code)]
 
 // ANCHOR: solution
 use std::cmp::Ordering;

src/iterators/Cargo.toml

@@ -4,6 +4,6 @@ version = "0.1.0"
 edition = "2021"
 publish = false
 
-[[bin]]
-name = "offset-differences"
+[lib]
+name = "offset_differences"
 path = "exercise.rs"

src/lifetimes/Cargo.toml

@@ -7,6 +7,6 @@ publish = false
 [dependencies]
 thiserror = "*"
 
-[[bin]]
+[lib]
 name = "protobuf"
 path = "exercise.rs"

src/lifetimes/exercise.rs

@@ -11,6 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+#![allow(dead_code)]
 
 // ANCHOR: solution
 // ANCHOR: preliminaries

src/pattern-matching/Cargo.toml

@@ -4,6 +4,6 @@ version = "0.1.0"
 edition = "2021"
 publish = false
 
-[[bin]]
+[lib]
 name = "eval"
 path = "exercise.rs"

src/smart-pointers/Cargo.toml

@@ -4,6 +4,6 @@ version = "0.1.0"
 edition = "2021"
 publish = false
 
-[[bin]]
-name = "binary-tree"
+[lib]
+name = "binary_tree"
 path = "exercise.rs"

src/smart-pointers/exercise.rs

@@ -11,6 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+#![allow(dead_code)]
 
 // ANCHOR: solution
 use std::cmp::Ordering;

src/std-traits/Cargo.toml

@@ -4,6 +4,6 @@ version = "0.1.0"
 edition = "2021"
 publish = false
 
-[[bin]]
-name = "std-traits"
+[lib]
+name = "std_traits"
 path = "exercise.rs"

src/testing/Cargo.toml

@@ -7,6 +7,6 @@ publish = false
 [lints.rust]
 unexpected_cfgs = { level = "warn", check-cfg = ['cfg(never)'] }
 
-[[bin]]
+[lib]
 name = "luhn"
 path = "exercise.rs"

src/testing/exercise.rs

@@ -11,6 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+#![allow(dead_code)]
 
 // This is the buggy version that appears in the problem.
 #[cfg(never)]