26 lines · cpp
1// RUN: %clang_cc1 -std=c++2a -verify %s2 3template<typename ...T, typename ...Lambda> void check_sizes(Lambda ...L) {4 static_assert(((sizeof(T) == sizeof(Lambda)) && ...));5}6 7template<typename ...T> void f(T ...v) {8 // Pack expansion of lambdas: each lambda captures only one pack element.9 check_sizes<T...>([=] { (void)&v; } ...);10 11 // Pack expansion inside lambda: captures all pack elements.12 auto l = [=] { ((void)&v, ...); };13 static_assert(sizeof(l) >= (sizeof(T) + ...));14}15 16template void f(int, char, double);17 18namespace PR41576 {19 template <class... Xs> constexpr int f(Xs ...xs) {20 return [&](auto ...ys) { // expected-note {{instantiation}}21 return ((xs + ys), ...); // expected-warning {{left operand of comma operator has no effect}}22 }(1, 2);23 }24 static_assert(f(3, 4) == 6); // expected-note {{instantiation}}25}26