This changes the exception error message of a bad-arguments error to
suppress the constructor argument when the failure is a constructor.
This changes both the "Invoked with: " output to omit the object
instances, and rewrites the constructor signature to make it look
like a constructor (changing the first argument to the object name, and
removing the ' -> NoneType' return type.
GCC-6 adds a -Wplacement-new warning that warns for placement-new into a
space that is too small, which is sometimes being triggered here (e.g.
example5 always generates the warning under g++-6). It's a false
warning, however: the line immediately before just checked the size, and
so this line is never going to actually be reached in the cases where
the GCC warning is being triggered.
This localizes the warning disabling just to this one spot as there are
other placement-new uses in pybind11 where this warning could warn about
legitimate future problems.
This commit adds an additional _ template function for compile-time
selection between two description strings. This in turn allows the
elimination of needing two name() methods in type_caster<arithmetic
types> and type_caster<eigen types>, which allows them to start using
PYBIND11_TYPE_CASTER instead, simplifying their code by eliminating all
the code that they are duplicating from the macro.
In eigen.h, type_caster<Type>::load(): For the 'ndim == 1' case, use
the 'InnerStride' type because there is only an inner stride for a
vector. Choose between (n_elts x 1) or (1 x n_elts) according to
whether we're constructing a Vector or a RowVector.
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.
