Add exception to assert introduced in #549 when the type caster of U* can produce the actual underlying object U
#608
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… can produce the actual underlying object U
include/nanobind/nb_cast.h
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| @@ -123,7 +124,9 @@ NB_INLINE uint8_t flags_for_local_caster(uint8_t flags) noexcept { | |||
| into storage owned by the caster, which won't live long enough. | |||
| Exception: the 'char' caster produces a result that points to | |||
| storage owned by the incoming Python 'str' object, so it's OK. */ | |||
| static_assert(!is_ref || std::is_same_v<T, const char*>, | |||
| static_assert(!is_ref || std::is_same_v<T, const char*> || | |||
| std::conjunction_v<std::is_pointer<T>, | |||
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Can you replace this with ordinary constexpr boolean expressions? (&&). Conjunction_v is unnecessarily heavy.
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You need is_pointer_v, etc. |
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What would be the best way to explain this change in the changelog @oremanj ? |
Hopefully after four attempts I've got it right :( |
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I originally used conjunction because I was worried about potentially forming an invalid expression if T was not a pointer type, but on second thought I don’t think it helps or matters. Possible changelog entry: “nanobind no longer prevents casting to a C++ container of pointers I’m mostly offline until Monday and will respond to this in more depth at that time if needed. |
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Thanks @oremanj , I've added what you suggested to the changelog. |
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Merged, thanks! |
Follow up to discussion #605.
I confirmed with my downstream project that the patch does indeed fix the regression introduced in nanobind 2.0.
Please note that, even though the commit has my name and email address, the actual patch was provided by @oremanj.