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Graph/e8d77d16-0ecd-4b4e-8fa1-bba66fd98323

Problemunvalidated

a += generate() should move elements but a += b should copy elements

e8d77d16-0ecd-4b4e-8fa1-bba66fd98323

a += generate() should move elements but a += b should copy elements

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Updated5/1/2026

PageRank0.0000

Effectiveness0.000

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8 linked nodes

DESCRIBESQuestion

CAUSED_BYRootCause

It seems the `forward()` always do a `move`. — for(auto &&data : rhs) { lhs.push_back(std::forward(data)); }. Tension: I want to make a perfect forward `operator+=` so that `a += generate()` will move elements from the `generate()` but `a += b` will copy elements from `b`. Outcome: `auto && data` is deduced as `Data & data`;.

CAUSED_BYRootCause

`std::forward(data)` forwards each loop variable as an rvalue because the range element is named `data`, not the original `rhs` value category

PERTAIN_TODomain

Forward References

PERTAIN_TODomain

FIXED_BYSolution

I think this could work: — template DataList & operator+=(DataList &lhs, T &&rhs) {. Tension: `a += generate()` will move elements from the `generate()` but `a += b` will copy elements from `b`. Outcome: if constexpr (std::is_rvalue_reference_v) lhs.emplace_back(std::move(data)); else lhs.emplace_back(data);.

FIXED_BYSolution

Use `std::views::as_rvalue(rhs)` for rvalue inputs and `lhs.append_range(rhs)` for lvalues

OCCURS_INLanguage

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