pybind11/include/pybind11/complex.h
Bruce Merry b82c0f0a2d Allow std::complex field with PYBIND11_NUMPY_DTYPE (#831)
This exposed a few underlying issues:

1. is_pod_struct was too strict to allow this. I've relaxed it to
require only trivially copyable and standard layout, rather than POD
(which additionally requires a trivial constructor, which std::complex
violates).

2. format_descriptor<std::complex<T>>::format() returned numpy format
strings instead of PEP3118 format strings, but register_dtype
feeds format codes of its fields to _dtype_from_pep3118. I've changed it
to return PEP3118 format codes. format_descriptor is a public type, so
this may be considered an incompatible change.

3. register_structured_dtype tried to be smart about whether to mark
fields as unaligned (with ^). However, it's examining the C++ alignment,
rather than what numpy (or possibly PEP3118) thinks the alignment should
be. For complex values those are different. I've made it mark all fields
as ^ unconditionally, which should always be safe even if they are
aligned, because we explicitly mark the padding.
2017-05-10 11:36:24 +02:00

62 lines
1.9 KiB
C++

/*
pybind11/complex.h: Complex number support
Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
All rights reserved. Use of this source code is governed by a
BSD-style license that can be found in the LICENSE file.
*/
#pragma once
#include "pybind11.h"
#include <complex>
/// glibc defines I as a macro which breaks things, e.g., boost template names
#ifdef I
# undef I
#endif
NAMESPACE_BEGIN(pybind11)
template <typename T> struct format_descriptor<std::complex<T>, detail::enable_if_t<std::is_floating_point<T>::value>> {
static constexpr const char c = format_descriptor<T>::c;
static constexpr const char value[3] = { 'Z', c, '\0' };
static std::string format() { return std::string(value); }
};
template <typename T> constexpr const char format_descriptor<
std::complex<T>, detail::enable_if_t<std::is_floating_point<T>::value>>::value[3];
NAMESPACE_BEGIN(detail)
template <typename T> struct is_fmt_numeric<std::complex<T>, detail::enable_if_t<std::is_floating_point<T>::value>> {
static constexpr bool value = true;
static constexpr int index = is_fmt_numeric<T>::index + 3;
};
template <typename T> class type_caster<std::complex<T>> {
public:
bool load(handle src, bool convert) {
if (!src)
return false;
if (!convert && !PyComplex_Check(src.ptr()))
return false;
Py_complex result = PyComplex_AsCComplex(src.ptr());
if (result.real == -1.0 && PyErr_Occurred()) {
PyErr_Clear();
return false;
}
value = std::complex<T>((T) result.real, (T) result.imag);
return true;
}
static handle cast(const std::complex<T> &src, return_value_policy /* policy */, handle /* parent */) {
return PyComplex_FromDoubles((double) src.real(), (double) src.imag());
}
PYBIND11_TYPE_CASTER(std::complex<T>, _("complex"));
};
NAMESPACE_END(detail)
NAMESPACE_END(pybind11)