fix: new maximum_adjacency_search interface, deprecating old broken one

[Becheler]

#297
#286

Before submitting

• This PR targets the develop branch.
• I searched for an existing PR or issue covering the same change.
• My contribution is licensed under the Boost Software License 1.0.

Type of change

• Bug fix
• New feature or API addition
• Refactor (no behavior change)
• Documentation
• Build, CI, or tooling
• Other (specify below)

Does this PR introduce a breaking change?

• Yes (describe migration impact below)
• No

What this PR does

Updated documentation page is available here: https://571.graph.prtest3.cppalliance.org/libs/graph/doc/html/graph/algorithms/utility/maximum_adjacency_search.html

All the changes had to be brought in a single PR to be able to land on develop without having tests/coverage/documentation out of sync.

• Refactor maximum adjacency search detail with a new detail::mas_sweep function
• add 2 new overloads for maximum_adjacency_search in boost::graph namespace :
  • 1 fully positional + doc example file
  • 1 convenience overload defaulting priority queue + doc example file
  • 1 convenience overload defaulting also the start vertex
• deprecated the old interface with unused parameter, as well as the named parameters overload
• updated the documentation to reflect those changes
• keep old interfaces tests as mas_test_old.cpp adding the BOOST_ALLOW_DEPRECATED_SYMBOLS to avoid CI warnings
• added the new interface tests as mast_test.cpp with modernized semantics.
• rewires stoer_wagner internals to use detail::mas_sweep with a visitor: not doing it in this PR would have led to dead code in detail::mas_sweep with failing test coverage.

PR #569 solidified tests for both SW and MAS so we can be confident this PR does not break existing interfaces.

Motivation

The main problems in #286 and #297 still remained. This PR should fix all of them:

• Pseudo-code in documentation never mentioned weights. The pseudo-code now shows reach_count[t] += weight(u, t), matching the implementation, and the parameter tables document the weight map.
• Dead code: a set that was never filled and a loop over it. That contraction path is no longer dead. stoer_wagner_phase now calls mas_sweep with a populated assignment set, so the loop is exercised.
• assignments was a dead (identity) parameter. The public interface is now the fully positional boost::graph::maximum_adjacency_search(g, weights, vis, start, pq) with no assignments parameter, plus a convenience overload. The old named-parameter and assignment-map forms are kept but deprecated (removal planned for 1.95).
• The noop line is gone with the sweep rewrite. Only a small identity indirection remained, and the Stoer-Wagner rewiring removes that too.

Testing

Checklist

• Existing tests pass (b2 in the test/ directory).
• New behavior is covered by a test, or this is a docs / build / refactor change.
• Documentation was updated if user-facing behavior changed.
• No new compiler warnings on the platforms I built against.

[github-actions]

Boost dependency footprint vs develop (auto-generated).
PR run 32992884482 vs develop run 32955412744 (69dd000ce6).

Header-inclusion weights (graph files pulling each direct dependency in):

Dependency	develop	PR	Δ
property_map	79	80	+1

Transitive Boost modules: 66 → 66 (0)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[github-actions]

Compiler-warning counts vs develop (auto-generated).
PR run 32992885108 vs develop run 32955412815 (69dd000ce6).

Job	Baseline	After	Delta
macos (clang, 14)	606	606	0
macos (clang, 17)	569	569	0
macos (clang, 20)	569	569	0
ubuntu (clang-19, 14)	606	606	0
ubuntu (clang-19, 17)	569	569	0
ubuntu (clang-19, 20)	569	569	0
ubuntu (clang-19, 23)	569	569	0
ubuntu (gcc-14, 14)	766	766	0
ubuntu (gcc-14, 17)	902	902	0
ubuntu (gcc-14, 20)	902	902	0
ubuntu (gcc-14, 23)	902	902	0
windows_msvc_14_3 (msvc-14.3)	938	944	+6

[cppalliance-bot]

An automated preview of the documentation is available at https://571.graph.prtest3.cppalliance.org/libs/graph/doc/html/index.html

If more commits are pushed to the pull request, the docs will rebuild at the same URL.

2026-08-26 17:15:29 UTC