Redesigned virtual call mechanism and user-facing syntax (breaking change!)
Sergey Lyskov pointed out that the trampoline mechanism used to override
virtual methods from within Python caused unnecessary overheads when
instantiating the original (i.e. non-extended) class.
This commit removes this inefficiency, but some syntax changes were
needed to achieve this. Projects using this features will need to make a
few changes:
In particular, the example below shows the old syntax to instantiate a
class with a trampoline:
class_<TrampolineClass>("MyClass")
.alias<MyClass>()
....
This is what should be used now:
class_<MyClass, std::unique_ptr<MyClass, TrampolineClass>("MyClass")
....
Importantly, the trampoline class is now specified as the *third*
argument to the class_ template, and the alias<..>() call is gone. The
second argument with the unique pointer is simply the default holder
type used by pybind11.
diff --git a/example/issues.ref b/example/issues.ref
index 4888ea5..58cc798 100644
--- a/example/issues.ref
+++ b/example/issues.ref
@@ -12,3 +12,9 @@
1. (int) -> int
Invoked with: 5.2
12.0
+C++ version
+A.f()
+Python version
+PyA.PyA()
+PyA.f()
+In python f()