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Merged
YannickJadoul merged 11 commits into from
Jan 30, 2021
Merged

When determining if a shared_ptr already exists, use a test on the we… #2819

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835e757
When determining if a shared_ptr already exists, use a test on the we…
elkhrt Jan 25, 2021
dbc2526
When determining if a shared_ptr already exists, use a test on the we…
elkhrt Jan 25, 2021
c48b0de
Merge branch 'exception_free_shared_ptr' of github.com:elkhrt/pybind1…
elkhrt Jan 25, 2021
c7210a2
weak_from_this is only available in C++17 and later
elkhrt Jan 28, 2021
a29d196
Switch to use feature flag instead of C++ version flag.
elkhrt Jan 30, 2021
6e375b6
Add Microsoft-specific check.
elkhrt Jan 30, 2021
8185b6f
Avoid undefined preprocessor macro warning treated as error.
elkhrt Jan 30, 2021
651fd41
Simplify shared_from_this in init_holder
YannickJadoul Jan 30, 2021
f8b1406
Include <version> in detail/common.h (~stolen~ borrowed from @bstalet…
YannickJadoul Jan 30, 2021
97a79f5
Move class_::get_shared_from_this to detail::try_get_shared_from_this
YannickJadoul Jan 30, 2021
22ba74a
Simplify try_get_shared_from_this by using weak_ptr::lock()
YannickJadoul Jan 30, 2021
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5 changes: 5 additions & 0 deletions include/pybind11/detail/common.h
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Original file line number Diff line number Diff line change
Expand Up @@ -162,6 +162,11 @@
#include <memory>
#include <typeindex>
#include <type_traits>
#if defined(__has_include)
# if __has_include(<version>)
# include <version>
# endif
#endif

#if PY_MAJOR_VERSION >= 3 /// Compatibility macros for various Python versions
#define PYBIND11_INSTANCE_METHOD_NEW(ptr, class_) PyInstanceMethod_New(ptr)
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32 changes: 24 additions & 8 deletions include/pybind11/pybind11.h
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Expand Up @@ -1501,18 +1501,34 @@ class class_ : public detail::generic_type {
}

private:
template <typename T>
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inline static std::shared_ptr<T> get_shared_from_this(std::enable_shared_from_this<T> *holder_value_ptr) {
#if defined(__cpp_lib_enable_shared_from_this) && (!defined(_MSC_VER) || _MSC_VER >= 1912)
if (!holder_value_ptr->weak_from_this().expired())
return holder_value_ptr->shared_from_this();
else
return nullptr;
#else
try {
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return holder_value_ptr->shared_from_this();
}
catch (const std::bad_weak_ptr &) {
return nullptr;
}
#endif
}

/// Initialize holder object, variant 1: object derives from enable_shared_from_this
template <typename T>
static void init_holder(detail::instance *inst, detail::value_and_holder &v_h,
const holder_type * /* unused */, const std::enable_shared_from_this<T> * /* dummy */) {
try {
auto sh = std::dynamic_pointer_cast<typename holder_type::element_type>(
v_h.value_ptr<type>()->shared_from_this());
if (sh) {
new (std::addressof(v_h.holder<holder_type>())) holder_type(std::move(sh));
v_h.set_holder_constructed();
}
} catch (const std::bad_weak_ptr &) {}

auto sh = std::dynamic_pointer_cast<typename holder_type::element_type>(
get_shared_from_this(v_h.value_ptr<type>()));
if (sh) {
new (std::addressof(v_h.holder<holder_type>())) holder_type(std::move(sh));
v_h.set_holder_constructed();
}

if (!v_h.holder_constructed() && inst->owned) {
new (std::addressof(v_h.holder<holder_type>())) holder_type(v_h.value_ptr<type>());
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