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/*
pybind11/descr.h: Helper type for concatenating type signatures either at runtime (C++11) or compile time (C++14)
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 "common.h"
NAMESPACE_BEGIN(pybind11) NAMESPACE_BEGIN(detail)
/* Concatenate type signatures at compile time using C++14 */ #if defined(PYBIND11_CPP14) && !defined(_MSC_VER)
#define PYBIND11_CONSTEXPR_DESCR
template <size_t Size1, size_t Size2> class descr { template <size_t Size1_, size_t Size2_> friend class descr; public: constexpr descr(char const (&text) [Size1+1], const std::type_info * const (&types)[Size2+1]) : descr(text, types, make_index_sequence<Size1>(), make_index_sequence<Size2>()) { }
constexpr const char *text() const { return m_text; } constexpr const std::type_info * const * types() const { return m_types; }
template <size_t OtherSize1, size_t OtherSize2> constexpr descr<Size1 + OtherSize1, Size2 + OtherSize2> operator+(const descr<OtherSize1, OtherSize2> &other) const { return concat(other, make_index_sequence<Size1>(), make_index_sequence<Size2>(), make_index_sequence<OtherSize1>(), make_index_sequence<OtherSize2>()); }
protected: template <size_t... Indices1, size_t... Indices2> constexpr descr( char const (&text) [Size1+1], const std::type_info * const (&types) [Size2+1], index_sequence<Indices1...>, index_sequence<Indices2...>) : m_text{text[Indices1]..., '\0'}, m_types{types[Indices2]..., nullptr } {}
template <size_t OtherSize1, size_t OtherSize2, size_t... Indices1, size_t... Indices2, size_t... OtherIndices1, size_t... OtherIndices2> constexpr descr<Size1 + OtherSize1, Size2 + OtherSize2> concat(const descr<OtherSize1, OtherSize2> &other, index_sequence<Indices1...>, index_sequence<Indices2...>, index_sequence<OtherIndices1...>, index_sequence<OtherIndices2...>) const { return descr<Size1 + OtherSize1, Size2 + OtherSize2>( { m_text[Indices1]..., other.m_text[OtherIndices1]..., '\0' }, { m_types[Indices2]..., other.m_types[OtherIndices2]..., nullptr } ); }
protected: char m_text[Size1 + 1]; const std::type_info * m_types[Size2 + 1]; };
template <size_t Size> constexpr descr<Size - 1, 0> _(char const(&text)[Size]) { return descr<Size - 1, 0>(text, { nullptr }); }
template <size_t Rem, size_t... Digits> struct int_to_str : int_to_str<Rem/10, Rem%10, Digits...> { }; template <size_t...Digits> struct int_to_str<0, Digits...> { static constexpr auto digits = descr<sizeof...(Digits), 0>({ ('0' + Digits)..., '\0' }, { nullptr }); };
// Ternary description (like std::conditional)
template <bool B, size_t Size1, size_t Size2> constexpr enable_if_t<B, descr<Size1 - 1, 0>> _(char const(&text1)[Size1], char const(&)[Size2]) { return _(text1); } template <bool B, size_t Size1, size_t Size2> constexpr enable_if_t<!B, descr<Size2 - 1, 0>> _(char const(&)[Size1], char const(&text2)[Size2]) { return _(text2); } template <bool B, size_t SizeA1, size_t SizeA2, size_t SizeB1, size_t SizeB2> constexpr enable_if_t<B, descr<SizeA1, SizeA2>> _(descr<SizeA1, SizeA2> d, descr<SizeB1, SizeB2>) { return d; } template <bool B, size_t SizeA1, size_t SizeA2, size_t SizeB1, size_t SizeB2> constexpr enable_if_t<!B, descr<SizeB1, SizeB2>> _(descr<SizeA1, SizeA2>, descr<SizeB1, SizeB2> d) { return d; }
template <size_t Size> auto constexpr _() -> decltype(int_to_str<Size / 10, Size % 10>::digits) { return int_to_str<Size / 10, Size % 10>::digits; }
template <typename Type> constexpr descr<1, 1> _() { return descr<1, 1>({ '%', '\0' }, { &typeid(Type), nullptr }); }
inline constexpr descr<0, 0> concat() { return _(""); } template <size_t Size1, size_t Size2, typename... Args> auto constexpr concat(descr<Size1, Size2> descr) { return descr; } template <size_t Size1, size_t Size2, typename... Args> auto constexpr concat(descr<Size1, Size2> descr, Args&&... args) { return descr + _(", ") + concat(args...); } template <size_t Size1, size_t Size2> auto constexpr type_descr(descr<Size1, Size2> descr) { return _("{") + descr + _("}"); }
#define PYBIND11_DESCR constexpr auto
#else /* Simpler C++11 implementation based on run-time memory allocation and copying */
class descr { public: PYBIND11_NOINLINE descr(const char *text, const std::type_info * const * types) { size_t nChars = len(text), nTypes = len(types); m_text = new char[nChars]; m_types = new const std::type_info *[nTypes]; memcpy(m_text, text, nChars * sizeof(char)); memcpy(m_types, types, nTypes * sizeof(const std::type_info *)); }
PYBIND11_NOINLINE descr operator+(descr &&d2) && { descr r;
size_t nChars1 = len(m_text), nTypes1 = len(m_types); size_t nChars2 = len(d2.m_text), nTypes2 = len(d2.m_types);
r.m_text = new char[nChars1 + nChars2 - 1]; r.m_types = new const std::type_info *[nTypes1 + nTypes2 - 1]; memcpy(r.m_text, m_text, (nChars1-1) * sizeof(char)); memcpy(r.m_text + nChars1 - 1, d2.m_text, nChars2 * sizeof(char)); memcpy(r.m_types, m_types, (nTypes1-1) * sizeof(std::type_info *)); memcpy(r.m_types + nTypes1 - 1, d2.m_types, nTypes2 * sizeof(std::type_info *));
delete[] m_text; delete[] m_types; delete[] d2.m_text; delete[] d2.m_types;
return r; }
char *text() { return m_text; } const std::type_info * * types() { return m_types; }
protected: PYBIND11_NOINLINE descr() { }
template <typename T> static size_t len(const T *ptr) { // return length including null termination
const T *it = ptr; while (*it++ != (T) 0) ; return static_cast<size_t>(it - ptr); }
const std::type_info **m_types = nullptr; char *m_text = nullptr; };
/* The 'PYBIND11_NOINLINE inline' combinations below are intentional to get the desired linkage while producing as little object code as possible */
PYBIND11_NOINLINE inline descr _(const char *text) { const std::type_info *types[1] = { nullptr }; return descr(text, types); }
template <bool B> PYBIND11_NOINLINE enable_if_t<B, descr> _(const char *text1, const char *) { return _(text1); } template <bool B> PYBIND11_NOINLINE enable_if_t<!B, descr> _(char const *, const char *text2) { return _(text2); } template <bool B> PYBIND11_NOINLINE enable_if_t<B, descr> _(descr d, descr) { return d; } template <bool B> PYBIND11_NOINLINE enable_if_t<!B, descr> _(descr, descr d) { return d; }
template <typename Type> PYBIND11_NOINLINE descr _() { const std::type_info *types[2] = { &typeid(Type), nullptr }; return descr("%", types); }
template <size_t Size> PYBIND11_NOINLINE descr _() { const std::type_info *types[1] = { nullptr }; return descr(std::to_string(Size).c_str(), types); }
PYBIND11_NOINLINE inline descr concat() { return _(""); } PYBIND11_NOINLINE inline descr concat(descr &&d) { return d; } template <typename... Args> PYBIND11_NOINLINE descr concat(descr &&d, Args&&... args) { return std::move(d) + _(", ") + concat(std::forward<Args>(args)...); } PYBIND11_NOINLINE inline descr type_descr(descr&& d) { return _("{") + std::move(d) + _("}"); }
#define PYBIND11_DESCR ::pybind11::detail::descr
#endif
NAMESPACE_END(detail) NAMESPACE_END(pybind11)
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