struct FlatHashMap(K, V = void, alias hasher = hashOf, string keyEqualPred = defaultKeyEqualPredOf!(K), Allocator = Mallocator, bool borrowChecked = false, bool useSmallLinearSearch = true, bool usePrimeCapacity = false)
enum passElementByValue =
(__traits(isCopyable, T) && is(T U == __argTypes) && U.length >= 1);
TODO remove when https://github.com/dlang/dmd/pull/11000 has been merged
@kinke: "The builtin __argTypes is (currently) only used/populated for Posix x64 (and AArch64 for LDC), and not used by GDC at all AFAIK".