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Merged
adalisk-emikhaylov merged 2 commits into from
Aug 25, 2026
Merged

Python: always pass the doc comment as a possibly-null pointer #47

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8113a9c
Python: always pass the comment as a possibly-null pointer
Fedr Aug 25, 2026
8e4f8be
Tweak the implementation a bit. Update the note on AI usage.
adalisk-emikhaylov Aug 25, 2026
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2 changes: 1 addition & 1 deletion README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -26,7 +26,7 @@ MRBind is meant to cover a large API surface area with minimal effort, but in tu

All MRBind features were developed without any use of AI.

I received some trivial vibecoded bugfix PRs that were merged after manual cleanup (which among other things includes replacing generated comments). I've also merged some generated testcases for those bugs.
I received some simple vibecoded contributions (bugfixes, binary size reductions) that were merged after manual cleanup, which among other things includes replacing the generated comments. I've also merged some generated testcases for those bugs.

## Usage

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31 changes: 17 additions & 14 deletions include/mrbind/targets/pybind11/core.h
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Expand Up @@ -3668,9 +3668,12 @@ static_assert(std::is_same_v<MRBind::RebindContainer<std::array<int, 4>, float>,
#define DETAIL_MB_PB11_CONV_OP_KIND_() MRBind::pb11::FuncKind::conv_op
#define DETAIL_MB_PB11_CONV_OP_KIND_explicit() MRBind::pb11::FuncKind::conv_op_explicit

// If the parameter is empty, returns `nullptr`. Otherwise prepends `+`. This is intended for optional comment strings, and `+` forces a conversion to a pointer, which helps reduce the number of instantiations.
// If the parameter is empty, returns `(const char *)nullptr`. Otherwise prepends `+`. This is intended for optional comment strings, and `+` forces a conversion to a pointer, which helps reduce the number of instantiations.
// The cast on `nullptr` is there for the same reason, to reduce the number of instantiations.
// It's good to use this macro instead of conditionally passing the comment, since it too reduces the number of instantiations,
// and Pybind apparently treats the null pointers as if no comment was passed at all.
#define DETAIL_MB_PB11_COMMENT_PTR(...) MRBIND_CAT(DETAIL_MB_PB11_COMMENT_PTR_, __VA_OPT__(1))(__VA_ARGS__)
#define DETAIL_MB_PB11_COMMENT_PTR_(...) nullptr
#define DETAIL_MB_PB11_COMMENT_PTR_(...) ((const char *)nullptr)
#define DETAIL_MB_PB11_COMMENT_PTR_1(...) +__VA_ARGS__

// Returns the "namespace marker" class for the given namespace stack.
Expand Down Expand Up @@ -3755,9 +3758,9 @@ static_assert(std::is_same_v<MRBind::RebindContainer<std::array<int, 4>, float>,
/* Pybind extras: */\
[](auto _pb11_f){_pb11_f(MRBIND_STRIP_LEADING_COMMA( \
/* Parameters. */\
DETAIL_MB_PB11_MAKE_PARAMS(params_) \
/* Comment, if any. */ \
MRBIND_PREPEND_COMMA(comment_) \
DETAIL_MB_PB11_MAKE_PARAMS(params_), \
/* Comment, possibly null. */ \
DETAIL_MB_PB11_COMMENT_PTR(comment_) \
/* Lifetime annotations. */ \
DETAIL_MB_PB11_KEEP_ALIVE(lifetimes_) \
));} \
Expand Down Expand Up @@ -3890,9 +3893,9 @@ static_assert(std::is_same_v<MRBind::RebindContainer<std::array<int, 4>, float>,
>(\
_pb11_c,\
/* Name. */\
MRBind::pb11::ToPythonName(MRBIND_STR(MRBIND_IDENTITY fullname_)).c_str()\
/* Comment, if any. */\
DETAIL_MB_PB11_PREPEND_COMMA_PLUS(comment_)\
MRBind::pb11::ToPythonName(MRBIND_STR(MRBIND_IDENTITY fullname_)).c_str(),\
/* Comment, possibly null. */\
DETAIL_MB_PB11_COMMENT_PTR(comment_)\
); \
/* Add `offsetof` static variables. */\
MRBIND_CAT(DETAIL_MB_PB11_DISPATCH_MEMBER_field_OFFSETOF_,static_)(qualname_, name_) \
Expand Down Expand Up @@ -3923,9 +3926,9 @@ static_assert(std::is_same_v<MRBind::RebindContainer<std::array<int, 4>, float>,
_pb11_c, \
&_pb11_state.func_scope_state, _pb11_state.pass_number \
/* Parameters. */\
DETAIL_MB_PB11_MAKE_PARAMS(params_) \
/* Comment, if any. */\
DETAIL_MB_PB11_PREPEND_COMMA_PLUS(comment_) \
DETAIL_MB_PB11_MAKE_PARAMS(params_), \
/* Comment, possibly null. */\
DETAIL_MB_PB11_COMMENT_PTR(comment_)\
/* Lifetime annotations. */ \
DETAIL_MB_PB11_KEEP_ALIVE(lifetimes_) \
);
Expand Down Expand Up @@ -3960,9 +3963,9 @@ static_assert(std::is_same_v<MRBind::RebindContainer<std::array<int, 4>, float>,
/* Pybind extras: */\
[](auto _pb11_f){_pb11_f(MRBIND_STRIP_LEADING_COMMA( \
/* Parameters. */\
DETAIL_MB_PB11_MAKE_PARAMS(params_) \
/* Comment, if any. */ \
MRBIND_PREPEND_COMMA(comment_) \
DETAIL_MB_PB11_MAKE_PARAMS(params_), \
/* Comment, possibly null. */ \
DETAIL_MB_PB11_COMMENT_PTR(comment_) \
/* Lifetime annotations. */ \
DETAIL_MB_PB11_KEEP_ALIVE(lifetimes_) \
));} \
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