完成12题

src/群友提交/第12题/loser_linker.cpp

@@ -0,0 +1,65 @@
+#include <cstdio>
+#include <vector>
+#include <type_traits>
+
+template<typename T,typename... Ts>
+auto make_vector(T&& t,Ts&&... ts)
+{
+    using vt = std::remove_cvref_t<std::common_type_t<T,Ts...>>;
+
+    return std::vector<vt> {
+        std::forward<vt>(ts)...
+    };
+}
+
+inline void dbg(const char* msg)
+{
+    std::puts(msg);
+    std::fflush(stdout);
+}
+
+struct X {
+    X() noexcept
+    {
+        dbg("X()");
+    };
+
+    ~X() noexcept
+    {
+        dbg("~X()");
+    };
+
+    X(const X&)
+    {
+        dbg("X(const X&)");
+    }
+
+    X(X&&) noexcept
+    {
+        dbg("X(X&&)");
+    }
+};
+
+void test()
+{
+    static_assert(requires {
+        {
+            make_vector(std::vector{1, 2, 3})
+        } -> std::same_as<std::vector<std::vector<int>>>;
+        {
+            make_vector(1, 2, 3)
+        } -> std::same_as<std::vector<int>>;
+        make_vector(1, 2, 3).size() == 3;
+    });
+    X    x1;
+    X    x2;
+    auto vec = make_vector(x1, std::move(x2));
+}
+
+int main()
+{
+    test();
+    dbg("test end");
+
+    return 0;
+}