Open
Description
If I declare a struct, and then use it as the result of an inspect, cppfront generates code constructing the struct with no arguments -- and there's no way to declare an operator= with no arguments in a struct!
Steps to reproduce the behavior:
https://cpp2.godbolt.org/z/K6f9h9qjx
action: @struct type = {
dx: int;
dy: int;
}
testfn: (x: int, y: int) -> action = {
return inspect (x,y) -> action {
is (0, 0) = action(1, 0);
is (0, 1) = action(0, 1);
is _ = action(1, 1);
};
}
cppfront generates this as the definition of action:
class action {
public: int dx;
public: int dy;
public: action(auto&& dx_, auto&& dy_)
CPP2_REQUIRES_ (std::is_convertible_v<CPP2_TYPEOF(dx_), std::add_const_t<int>&> && std::is_convertible_v<CPP2_TYPEOF(dy_), std::add_const_t<int>&>) ;
};
and this as the definition of testfn:
[[nodiscard]] auto testfn(cpp2::impl::in<int> x, cpp2::impl::in<int> y) -> action{
return [&] () -> action { auto&& _expr = (x, y);
if (cpp2::impl::is(_expr, (0, 0))) { if constexpr( requires{action(1, 0);} ) if constexpr( std::is_convertible_v<CPP2_TYPEOF((action(1, 0))),action> ) return action(1, 0); else return action{}; else return action{}; }
else if (cpp2::impl::is(_expr, 0, 1)) { if constexpr( requires{action(0, 1);} ) if constexpr( std::is_convertible_v<CPP2_TYPEOF((action(0, 1))),action> ) return action(0, 1); else return action{}; else return action{}; }
else return action(1, 1); }
();
}
Obviously action{} is a zero-parameter constructor, and action doesn't have any zero-argument constructors. (And even if I ensure that action{} is on a code path never taken, both gcc 14 and Clang 19 try to compile it and throw an error.)