clang-tidy: check and fix cppcoreguidelines-use-default-member-init

[Mohit242-bit]

Fixes #3041

Summary

• Enable cppcoreguidelines-use-default-member-init in .clang-tidy.
• Refactor initialization in these classes to use default member initializers:
  • Pgr_bdAstar
  • PgrDirectedChPPGraph
  • Pgr_contractionGraph
  • Pgr_bidirectional
  • dijkstra_distance_visitor_no_init
  • Solution
  • Pgr_ksp

Changes proposed in this pull request

• Update .clang-tidy to enable cppcoreguidelines-use-default-member-init.
• Refactor constructor initializations as per the guideline for the classes above.
• Run clang-tidy and ensure no violations remain for this check.
• All tests and builds pass locally with the new code style.

@pgRouting/admins

Summary by CodeRabbit

• Refactor
  • Standardized default value handling across the codebase by moving many initializations into member declarations.
  • Removed one now-unneeded internal member and simplified constructors accordingly.
  • Internal cleanup only — no changes to user-facing behavior or public interfaces.

[coderabbitai]

Walkthrough

Enabled the cppcoreguidelines-use-default-member-init clang-tidy check and updated multiple classes to move member initializers from constructor initializer lists into in-class default member initializers; also removed the EPSILON member from the VRP Solution class.

Changes

Cohort / File(s)	Summary
Clang-tidy config /.clang-tidy	Removed exclusion for cppcoreguidelines-use-default-member-init, enabling the check.
bdAstar include/bdAstar/bdAstar.hpp	Moved m_heuristic and m_factor initialization from constructor to in-class defaults.
Chinese Postman include/chinese/chinesePostman.hpp	Added in-class defaults for totalDeg{0} and totalCost{0} (previously constructor-initialized).
Contraction Graph include/contraction/contractionGraph.hpp	Added in-class default min_edge_id{0} instead of constructor initializer.
Bidirectional search include/cpp_common/bidirectional.hpp	Moved best_cost initialization to in-class default (best_cost{0}).
Dijkstra visitors include/visitors/dijkstra_visitors.hpp	Moved m_num_examined initialization to in-class default (m_num_examined{0}).
VRP solution include/vrp/solution.hpp, src/pickDeliver/solution.cpp	Removed protected EPSILON member and removed its constructor initialization.
Yen K-shortest paths include/yen/ksp.hpp	Added in-class defaults for m_start{0}, m_end{0}, m_K{0}, m_heap_paths{false} and removed those initializers from the constructor.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• Have clang tidy with checks that actually pass #3028 — Enables cppcoreguidelines checks and applies related fixes (same clang-tidy rule family).
• Check cppcoreguidelines-prefer-member-initializer and fix code #3020 — Similar member-initialization edits affecting headers like include/yen/ksp.hpp.

Suggested labels

Enhancement, C/C++

Suggested reviewers

• cvvergara
• robe2

Poem

🐇 I nibble defaults in the code so neat,
I tuck them into members, soft and sweet.
Constructors breathe easier, calm and light,
Defaults snugly guard them through the night.
Hooray — a tidy hop, all set just right! ✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main objective of enabling and fixing the cppcoreguidelines-use-default-member-init clang-tidy check.
Linked Issues check	✅ Passed	All code changes align with issue #3041: the cppcoreguidelines-use-default-member-init check is enabled in .clang-tidy, and violations are fixed across multiple classes.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to enabling and fixing the cppcoreguidelines-use-default-member-init check; no unrelated modifications are present.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

---

No actionable comments were generated in the recent review. 🎉

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

Actionable comments posted: 1

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

include/vrp/solution.hpp (1)

74-78: ⚠️ Potential issue | 🟠 Major

Copy assignment operator no longer copies EPSILON — behavioral change.

The AI summary indicates that EPSILON = sol.EPSILON was previously present in this operator body and has been removed. If EPSILON is ever modified after construction (it's a non-const, non-static protected member, so subclasses can modify it), the copy assignment will silently drop that change.

If EPSILON is truly immutable, this is harmless but the type should reflect that (see the static constexpr suggestion above). If it can vary per instance, it must be copied here:

🐛 Proposed fix if EPSILON can vary per instance

  Solution& operator = (const Solution& sol) {
+      EPSILON = sol.EPSILON;
       fleet = sol.fleet;
       trucks = sol.trucks;
       return *this;
  };

🤖 Fix all issues with AI agents

In `@include/vrp/solution.hpp`:
- Line 49: EPSILON is declared as a non-const instance member; change it to a
compile-time constant by replacing the instance field with a static constexpr
double (e.g., static constexpr double EPSILON = 0.0001;) in the same scope
(class/namespace) so there is one immutable value shared across all instances;
update any code that relied on an instance pointer/reference to EPSILON to
access it as a static member (ClassName::EPSILON or simply EPSILON if in the
same namespace/scope).

[Copilot]

Pull request overview

Enables the cppcoreguidelines-use-default-member-init clang-tidy check and updates several C++ classes to use in-class default member initializers instead of constructor initializer lists, aligning the codebase with the guideline.

Changes:

• Enable cppcoreguidelines-use-default-member-init by updating .clang-tidy.
• Refactor multiple classes/structs to use default member initializers (removing redundant constructor initializations).
• Simplify constructors accordingly across affected components (VRP, Yen KSP, bidirectional search, contraction, Chinese Postman, visitors).

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
.clang-tidy	Enables cppcoreguidelines-use-default-member-init by no longer excluding it.
include/bdAstar/bdAstar.hpp	Moves m_heuristic/m_factor to in-class initializers and simplifies ctor.
include/chinese/chinesePostman.hpp	Moves totalDeg/totalCost to in-class initializers and removes redundant ctor init.
include/contraction/contractionGraph.hpp	Moves min_edge_id to an in-class initializer and simplifies ctor.
include/cpp_common/bidirectional.hpp	Moves best_cost to an in-class initializer and removes redundant ctor init.
include/visitors/dijkstra_visitors.hpp	Moves m_num_examined to an in-class initializer and removes redundant ctor init.
include/vrp/solution.hpp	Moves EPSILON to an in-class initializer and removes redundant ctor/copy ctor/assignment initialization.
include/yen/ksp.hpp	Moves scalar members to in-class initializers and simplifies ctor initializer list.
src/pickDeliver/solution.cpp	Removes redundant EPSILON initialization from Solution constructor.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@include/vrp/solution.hpp`:
- Around line 48-49: In class Solution fix the indentation of the access
specifier so it is indented one space inside the class (change the line with
"protected:" so it aligns with other class members), e.g. ensure "protected:"
sits at the same column as member declarations like
"std::deque<Vehicle_pickDeliver> fleet;" to satisfy CI whitespace rules.