[libcxx-commits] [libcxx] [libc++] P3168R2 Give std::optional Range Support (PR #146491)

[Yanzuo Liu via libcxx-commits]

zwuis wrote:

> ```c++
>  _LIBCPP_HIDE_FROM_ABI constexpr reference operator*() const {
>     if (__ptr_ == nullptr)
>       std::__throw_runtime_error("deferencering end iterator");
>     return *__ptr_;
>   }
> 
>   _LIBCPP_HIDE_FROM_ABI constexpr pointer operator->() const {
>     if (__ptr_ == nullptr)
>       std::__throw_runtime_error("deferencering end iterator");
>     return *__ptr_;
>   }
> ```
> 
> Should these functions return `__ptr_` instead of throwing exceptions if `__ptr_` is nullptr? Throwing exceptions is not allowed in constexpr functions

`*end()` is UB so this `if` statement should be removed.

https://github.com/llvm/llvm-project/pull/146491