Reimplement py::init<...> to use common factory code
This reimplements the py::init<...> implementations using the various
functions added to support `py::init(...)`, and moves the implementing
structs into `detail/init.h` from `pybind11.h`. It doesn't simply use a
factory directly, as this is a very common case and implementation
without an extra lambda call is a small but useful optimization.
This, combined with the previous lazy initialization, also avoids
needing placement new for `py::init<...>()` construction: such
construction now occurs via an ordinary `new Type(...)`.
A consequence of this is that it also fixes a potential bug when using
multiple inheritance from Python: it was very easy to write classes
that double-initialize an existing instance which had the potential to
leak for non-pod classes. With the new implementation, an attempt to
call `__init__` on an already-initialized object is now ignored. (This
was already done in the previous commit for factory constructors).
This change exposed a few warnings (fixed here) from deleting a pointer
to a base class with virtual functions but without a virtual destructor.
These look like legitimate warnings that we shouldn't suppress; this
adds virtual destructors to the appropriate classes.
diff --git a/tests/test_class.py b/tests/test_class.py
index 7381c4a..9c5049f 100644
--- a/tests/test_class.py
+++ b/tests/test_class.py
@@ -141,11 +141,8 @@
d = m.HasOpNewDelBoth()
assert capture == """
A new 8
- A placement-new 8
B new 4
- B placement-new 4
D new 32
- D placement-new 32
"""
sz_alias = str(m.AliasedHasOpNewDelSize.size_alias)
sz_noalias = str(m.AliasedHasOpNewDelSize.size_noalias)
@@ -153,8 +150,8 @@
c = m.AliasedHasOpNewDelSize()
c2 = SubAliased()
assert capture == (
- "C new " + sz_alias + "\nC placement-new " + sz_noalias + "\n" +
- "C new " + sz_alias + "\nC placement-new " + sz_alias + "\n"
+ "C new " + sz_noalias + "\n" +
+ "C new " + sz_alias + "\n"
)
with capture: