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1// -*- C++ -*-2//===----------------------------------------------------------------------===//3//4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.5// See https://llvm.org/LICENSE.txt for license information.6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP___FORMAT_FORMAT_ARGS_H11#define _LIBCPP___FORMAT_FORMAT_ARGS_H12 13#include <__config>14#include <__cstddef/size_t.h>15#include <__format/format_arg.h>16#include <__format/format_arg_store.h>17#include <__fwd/format.h>18#include <cstdint>19 20#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)21# pragma GCC system_header22#endif23 24_LIBCPP_BEGIN_NAMESPACE_STD25 26#if _LIBCPP_STD_VER >= 2027 28template <class _Context>29class basic_format_args {30public:31 template <class... _Args>32 _LIBCPP_HIDE_FROM_ABI basic_format_args(const __format_arg_store<_Context, _Args...>& __store) noexcept33 : __size_(sizeof...(_Args)) {34 if constexpr (sizeof...(_Args) != 0) {35 if constexpr (__format::__use_packed_format_arg_store(sizeof...(_Args))) {36 __values_ = __store.__storage.__values_;37 __types_ = __store.__storage.__types_;38 } else39 __args_ = __store.__storage.__args_;40 }41 }42 43 _LIBCPP_HIDE_FROM_ABI basic_format_arg<_Context> get(size_t __id) const noexcept {44 if (__id >= __size_)45 return basic_format_arg<_Context>{};46 47 if (__format::__use_packed_format_arg_store(__size_))48 return basic_format_arg<_Context>{__format::__get_packed_type(__types_, __id), __values_[__id]};49 50 return __args_[__id];51 }52 53 _LIBCPP_HIDE_FROM_ABI size_t __size() const noexcept { return __size_; }54 55private:56 size_t __size_{0};57 // [format.args]/558 // [Note 1: Implementations are encouraged to optimize the representation of59 // basic_format_args for small number of formatting arguments by storing60 // indices of type alternatives separately from values and packing the61 // former. - end note]62 union {63 struct {64 const __basic_format_arg_value<_Context>* __values_;65 uint64_t __types_;66 };67 const basic_format_arg<_Context>* __args_;68 };69};70 71template <class _Context, class... _Args>72basic_format_args(__format_arg_store<_Context, _Args...>) -> basic_format_args<_Context>;73 74#endif // _LIBCPP_STD_VER >= 2075 76_LIBCPP_END_NAMESPACE_STD77 78#endif // _LIBCPP___FORMAT_FORMAT_ARGS_H79