Method copy

test/testregex.cpp:94–122

    }

    void copy() const {
        const auto r = assertRegex("begin.*end");

        int called = 0;
        int s = -1;
        int e = -1;
        auto f = [&](int start, int end) {
            ++called;
            s = start;
            e = end;
        };

        {
            // NOLINTNEXTLINE(performance-unnecessary-copy-initialization)
            auto r2 = r;
            ASSERT_EQUALS("", r2->match("begin-123-end", f));
            ASSERT_EQUALS(1, called);
            ASSERT_EQUALS(0, s);
            ASSERT_EQUALS(13, e);
        }

        called = 0;
        s = -1;
        e = -1;
        ASSERT_EQUALS("", r->match("begin-123-end", f));
        ASSERT_EQUALS(1, called);
        ASSERT_EQUALS(0, s);
        ASSERT_EQUALS(13, e);
    }

    void multimatch() const {
        const auto r = assertRegex("info:.*");