clang-tidy: fix explicit virtual functions in remaining headers

[sakirr05]

Fixes: #3045

Summary

This PR enables the cppcoreguidelines-explicit-virtual-functions check and fixes the remaining violations by explicitly marking overridden virtual functions with override.

The changes are limited to C++ header files and are purely mechanical.

Details

• Enable cppcoreguidelines-explicit-virtual-functions in .clang-tidy
• Add override to virtual function overrides in remaining include headers
• assert.hpp is intentionally excluded (handled separately in Check and fix assert.hpp for cppcoreguidelines-explicit-virtual-functions #3044)

Example

Before:

class Pgr_bdDijkstra : public Pgr_bidirectional<G> {
public:
    ~Pgr_bdDijkstra();
    void explore_forward(const Cost_Vertex_pair &node);
};

After:

class Pgr_bdDijkstra : public Pgr_bidirectional<G> {
public:
    ~Pgr_bdDijkstra() override;
    void explore_forward(const Cost_Vertex_pair &node) override;
};

Summary by CodeRabbit

• Refactor
  • Improved code quality standards compliance by enhancing virtual method declarations across core modules to align with modern C++ best practices.

[coderabbitai]

Walkthrough

This PR enables the cppcoreguidelines-explicit-virtual-functions clang-tidy check and adds the override specifier to virtual function declarations across six header files to comply with the check's requirements.

Changes

Cohort / File(s)	Summary
Configuration .clang-tidy	Removed cppcoreguidelines-explicit-virtual-functions from the disabled Checks list, enabling it by default.
Bidirectional Search Classes include/bdAstar/bdAstar.hpp, include/bdDijkstra/bdDijkstra.hpp	Added override specifier to destructors and private virtual methods (explore_forward, explore_backward) in bidirectional A* and Dijkstra implementations.
Spanning Tree Classes include/spanningTree/kruskal.hpp, include/spanningTree/prim.hpp	Added override specifier to destructors and generate_mst method in Kruskal and Prim algorithm implementations.
Visitor Methods include/yen/turnRestrictedPath.hpp	Added override specifier to visitor callback methods (on_insert_first_solution, on_insert_to_heap) in turn-restricted path visitor class.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• clang-tidy: check and fix cppcoreguidelines-virtual-class-destructor #3029: Modifies destructors and virtual method qualifiers in the same classes (Pgr_bdAstar, Pgr_bdDijkstra, Pgr_kruskal, Pgr_prim).
• Have clang tidy with checks that actually pass #3028: Related cppcoreguidelines check configuration and corresponding code fixes with override specifiers.
• clang-tidy: fix assert.hpp cppcoreguidelines-explicit-virtual-functions #3005: Enables cppcoreguidelines-explicit-virtual-functions check and applies similar override/noexcept fixes to header files.

Suggested labels

Enhancement, C/C++

Suggested reviewers

• cvvergara
• robe2

Poem

🐰 Override's the word today,
Virtual functions find their way,
With explicit declarations bright,
Clang-tidy settles down to right,
Compliance hops in every class! ✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% 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 clearly summarizes the main change: enabling a clang-tidy check and fixing virtual function declarations with override specifiers.
Linked Issues check	✅ Passed	The PR fulfills the objectives from #3045: enables cppcoreguidelines-explicit-virtual-functions check in .clang-tidy and adds override specifiers to all overridden virtual functions across multiple header files.
Out of Scope Changes check	✅ Passed	All changes are in-scope: enabling the clang-tidy check and adding override specifiers to virtual functions across the specified headers, with assert.hpp intentionally excluded.

_{✏️ 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

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[coderabbitai]

Actionable comments posted: 8

🤖 Fix all issues with AI agents

In `@include/dagShortestPath/dagShortestPath.hpp`:
- Around line 199-200: The template member function examine_vertex(V u, B_G &)
in class inheriting from boost::default_dijkstra_visitor should not use the C++
override specifier because override cannot be applied to function templates when
matching a non-template virtual base; remove the trailing "override" from the
examine_vertex template declaration so the method compiles and still provides
the intended visitor behavior with boost::default_dijkstra_visitor.

In `@include/visitors/astar_visitors.hpp`:
- Around line 45-46: The member function template examine_vertex (template
<class B_G> void examine_vertex(V u, B_G &g)) in astar_visitors.hpp incorrectly
uses the override specifier even though
boost::default_astar_visitor::examine_vertex is a template and not a virtual
function; remove the trailing "override" from the examine_vertex
declaration/definition in the astar visitor class (same fix as you applied in
prim_dijkstra_visitor.hpp) so the code compiles.

In `@include/visitors/dfs_visitor_with_root.hpp`:
- Around line 50-55: The template member functions tree_edge(E e, const B_G&)
and start_vertex(V v, const B_G&) in dfs_visitor_with_root.hpp are incorrectly
declared with the override specifier; remove the override keyword from both
method declarations (the ones that push to m_data and check v != m_roots) so the
class compiles as a Boost graph visitor using static (template) dispatch.

In `@include/visitors/dfs_visitor.hpp`:
- Around line 61-62: The three member function templates start_vertex,
examine_edge, and tree_edge in your dfs visitor class are incorrectly marked
with override (these are templates matching boost::default_dfs_visitor
non-virtual template methods), so remove the trailing "override" from the
template method declarations/definitions (e.g., the template<typename B_G> void
start_vertex(V v, const B_G&), template<typename B_G> void examine_edge(E e,
const B_G&), and template<typename B_G> void tree_edge(E e, const B_G&) in your
dfs_visitor class) so they compile without attempting to override non-virtual
base methods.

In `@include/visitors/dijkstra_visitors.hpp`:
- Line 93: Remove the invalid override specifiers from the template callback
methods in the Dijkstra visitor classes: delete the `override` keyword from the
template member functions `examine_vertex`, `examine_edge`, `edge_not_relaxed`,
and `discover_vertex` where they appear in the classes
`dijkstra_many_goal_visitor`, `dijkstra_distance_visitor`, and
`dijkstra_distance_visitor_no_init` (these are the non-virtual template methods
intended to satisfy Boost's visitor concept); leave other non-template visitors
(e.g. `dijkstra_one_goal_visitor`, `dijkstra_max_distance_visitor`) unchanged.

In `@include/visitors/edges_order_bfs_visitor.hpp`:
- Around line 46-47: The member function template declaration "template <class
B_G> void tree_edge(E e, const B_G&)" in edges_order_bfs_visitor.hpp cannot use
the 'override' specifier against boost::default_bfs_visitor (a non-template base
method), so remove the 'override' token from the tree_edge declaration; locate
the template<class B_G> void tree_edge(...) definition and delete 'override' so
the method compiles without attempting to override a non-template base member.

In `@include/visitors/edges_order_dfs_visitor.hpp`:
- Around line 47-48: The member function template tree_edge(E e, const B_G&) in
the visitor class is marked with override but cannot override a template from
the boost::default_dfs_visitor base; remove the trailing "override" specifier
from the tree_edge template declaration (and any other member function templates
in the same class that use "override") so the compiler stops reporting the
invalid override against boost::default_dfs_visitor.

In `@include/visitors/prim_dijkstra_visitor.hpp`:
- Around line 47-48: The finish_vertex member function template in the
prim_dijkstra_visitor class (the declaration "template<class B_G> void
finish_vertex(V v, B_G&) override") is ill-formed because member function
templates cannot be virtual and thus cannot use the override specifier; remove
the trailing "override" from the finish_vertex template declaration so it
becomes a regular template method (locate the finish_vertex template in
prim_dijkstra_visitor and delete the "override" keyword).

[sakirr05]

Hi @cvvergara, this PR finishes the remaining work for #3045 under #3043. I enabled cppcoreguidelines-explicit-virtual-functions and added override only where the base class actually defines virtual methods. For Boost graph visitors, override was removed since those callbacks are non-virtual templates. The changes are header-only, mechanical, and don’t affect behavior or APIs; assert.hpp was already handled in #3044. Would appreciate a review when you get a chance