chore: increase MSRV to 1.87.0

.github/copilot-instructions.md

@@ -6,7 +6,7 @@
 
  **Key Facts:**
  - **Language:** Rust (edition 2024)
- - **MSRV:** 1.86.0 (Minimum Supported Rust Version)
+ - **MSRV:** 1.87.0 (Minimum Supported Rust Version)
  - **Size:** ~6,000 lines of source code, ~4,400 lines of tests
  - **Type:** Library crate (no binary)
  - **Dependencies:** Minimal (num-traits, indexmap, rustc-hash, integer-sqrt, thiserror, deprecate-until)
@@ -15,7 +15,7 @@
  ## Build and Validation Commands
 
  ### Prerequisites
- All commands should be run from the repository root. The project requires Rust toolchain (stable, beta, nightly, or MSRV 1.86.0).
+ All commands should be run from the repository root. The project requires Rust toolchain (stable, beta, nightly, or MSRV 1.87.0).
 
  ### Essential Commands (In Order)
 
@@ -99,7 +99,7 @@
  ## Project Structure
 
  ### Root Directory Files
- - `Cargo.toml` - Project manifest with dependencies, MSRV (rust-version = "1.86.0"), and linting configuration
+ - `Cargo.toml` - Project manifest with dependencies, MSRV (rust-version = "1.87.0"), and linting configuration
  - `Cargo.lock` - Locked dependency versions
  - `README.md` - User-facing documentation
  - `CHANGELOG.md` - Version history
@@ -166,6 +166,20 @@
  3. **codspeed.yml** (Runs on main branch pushes and PRs):
     - Runs performance benchmarks
 
+ ## MSRV (Minimum Supported Rust Version)
+
+ When updating the MSRV, you must update it in the following locations:
+ 1. **Cargo.toml** - The `rust-version` field (line 14)
+ 2. **src/lib.rs** - Documentation comment stating "The minimum supported Rust version (MSRV) is Rust X.Y.Z" (line 89)
+ 3. **.github/copilot-instructions.md** - Three locations:
+    - "MSRV: X.Y.Z" in Key Facts section (line 9)
+    - "MSRV X.Y.Z" in Prerequisites section (line 18)
+    - "rust-version = X.Y.Z" in Root Directory Files section (line 102)
+
+ **Note:** The GitHub Actions workflow (.github/workflows/tests.yml) automatically reads the MSRV from Cargo.toml, so it does not need manual updates.
+
+ After updating the MSRV, always run `sh tests/check-msrv-consistency.sh` to verify that Cargo.toml and src/lib.rs are in sync.
+
  ## Critical Validation Rules
 
  ### Before Committing

Cargo.toml

@@ -11,7 +11,7 @@ authors = ["Samuel Tardieu <sam@rfc1149.net>"]
 categories = ["algorithms"]
 readme = "README.md"
 edition = "2024"
-rust-version = "1.86.0"
+rust-version = "1.87.0"
 include = [
     "src/**/*",
     "tests/**/*",

src/lib.rs

@@ -86,7 +86,7 @@
 //! in this context, you can wrap them into compliant types using the
 //! [ordered-float](https://crates.io/crates/ordered-float) crate.
 //!
-//! The minimum supported Rust version (MSRV) is Rust 1.86.0.
+//! The minimum supported Rust version (MSRV) is Rust 1.87.0.
 //!
 //! [A*]: https://en.wikipedia.org/wiki/A*_search_algorithm
 //! [BFS]: https://en.wikipedia.org/wiki/Breadth-first_search