Compilare: main.cpp: In function 'int main()': main.cpp:109:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 109 | for(int j = 0 ; j < L[i].size() ; ++ j) | ~~^~~~~~~~~~~~~ In constructor 'constexpr aint::aint(aint&&)', inlined from 'constexpr decltype (::new(void*(0)) _Tp) std::construct_at(_Tp*, _Args&& ...) [with _Tp = aint; _Args = {aint}]' at /usr/include/c++/12.2.1/bits/stl_construct.h:97:14, inlined from 'static constexpr void std::allocator_traits<std::allocator<_CharT> >::construct(allocator_type&, _Up*, _Args&& ...) [with _Up = aint; _Args = {aint}; _Tp = aint]' at /usr/include/c++/12.2.1/bits/alloc_traits.h:518:21, inlined from 'constexpr std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {aint}; _Tp = aint; _Alloc = std::allocator<aint>]' at /usr/include/c++/12.2.1/bits/vector.tcc:117:30, inlined from 'constexpr void std::vector<_Tp, _Alloc>::push_back(value_type&&) [with _Tp = aint; _Alloc = std::allocator<aint>]' at /usr/include/c++/12.2.1/bits/stl_vector.h:1294:21, inlined from 'int main()' at main.cpp:106:16: main.cpp:26:8: warning: '<unnamed>.aint::M' may be used uninitialized [-Wmaybe-uninitialized] 26 | struct aint{ | ^~~~ main.cpp: In function 'int main()': main.cpp:106:22: note: '<anonymous>' declared here 106 | T.push_back(aint()); | ^