xref: /freebsd-src/contrib/llvm-project/libcxx/include/__format/format_args.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1349cc55cSDimitry Andric // -*- C++ -*-
2349cc55cSDimitry Andric //===----------------------------------------------------------------------===//
3349cc55cSDimitry Andric //
4349cc55cSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5349cc55cSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
6349cc55cSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7349cc55cSDimitry Andric //
8349cc55cSDimitry Andric //===----------------------------------------------------------------------===//
9349cc55cSDimitry Andric 
10349cc55cSDimitry Andric #ifndef _LIBCPP___FORMAT_FORMAT_ARGS_H
11349cc55cSDimitry Andric #define _LIBCPP___FORMAT_FORMAT_ARGS_H
12349cc55cSDimitry Andric 
13349cc55cSDimitry Andric #include <__config>
1481ad6265SDimitry Andric #include <__format/format_arg.h>
1581ad6265SDimitry Andric #include <__format/format_arg_store.h>
16*0fca6ea1SDimitry Andric #include <__fwd/format.h>
17349cc55cSDimitry Andric #include <cstddef>
1881ad6265SDimitry Andric #include <cstdint>
19349cc55cSDimitry Andric 
20349cc55cSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
21349cc55cSDimitry Andric #  pragma GCC system_header
22349cc55cSDimitry Andric #endif
23349cc55cSDimitry Andric 
24349cc55cSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
25349cc55cSDimitry Andric 
2606c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20
27349cc55cSDimitry Andric 
28349cc55cSDimitry Andric template <class _Context>
2906c3fb27SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_format_args {
30349cc55cSDimitry Andric public:
31349cc55cSDimitry Andric   template <class... _Args>
3281ad6265SDimitry Andric   _LIBCPP_HIDE_FROM_ABI basic_format_args(const __format_arg_store<_Context, _Args...>& __store) noexcept
3381ad6265SDimitry Andric       : __size_(sizeof...(_Args)) {
3481ad6265SDimitry Andric     if constexpr (sizeof...(_Args) != 0) {
3581ad6265SDimitry Andric       if constexpr (__format::__use_packed_format_arg_store(sizeof...(_Args))) {
3681ad6265SDimitry Andric         __values_ = __store.__storage.__values_;
3781ad6265SDimitry Andric         __types_  = __store.__storage.__types_;
3881ad6265SDimitry Andric       } else
3981ad6265SDimitry Andric         __args_ = __store.__storage.__args_;
4081ad6265SDimitry Andric     }
4181ad6265SDimitry Andric   }
42349cc55cSDimitry Andric 
43cb14a3feSDimitry Andric   _LIBCPP_HIDE_FROM_ABI basic_format_arg<_Context> get(size_t __id) const noexcept {
4481ad6265SDimitry Andric     if (__id >= __size_)
4581ad6265SDimitry Andric       return basic_format_arg<_Context>{};
4681ad6265SDimitry Andric 
4781ad6265SDimitry Andric     if (__format::__use_packed_format_arg_store(__size_))
4881ad6265SDimitry Andric       return basic_format_arg<_Context>{__format::__get_packed_type(__types_, __id), __values_[__id]};
4981ad6265SDimitry Andric 
5081ad6265SDimitry Andric     return __args_[__id];
51349cc55cSDimitry Andric   }
52349cc55cSDimitry Andric 
53349cc55cSDimitry Andric   _LIBCPP_HIDE_FROM_ABI size_t __size() const noexcept { return __size_; }
54349cc55cSDimitry Andric 
55349cc55cSDimitry Andric private:
56349cc55cSDimitry Andric   size_t __size_{0};
5781ad6265SDimitry Andric   // [format.args]/5
5881ad6265SDimitry Andric   // [Note 1: Implementations are encouraged to optimize the representation of
5981ad6265SDimitry Andric   // basic_format_args for small number of formatting arguments by storing
6081ad6265SDimitry Andric   // indices of type alternatives separately from values and packing the
6181ad6265SDimitry Andric   // former. - end note]
6281ad6265SDimitry Andric   union {
6381ad6265SDimitry Andric     struct {
6481ad6265SDimitry Andric       const __basic_format_arg_value<_Context>* __values_;
6581ad6265SDimitry Andric       uint64_t __types_;
66349cc55cSDimitry Andric     };
6781ad6265SDimitry Andric     const basic_format_arg<_Context>* __args_;
6881ad6265SDimitry Andric   };
6981ad6265SDimitry Andric };
70349cc55cSDimitry Andric 
7106c3fb27SDimitry Andric template <class _Context, class... _Args>
7206c3fb27SDimitry Andric basic_format_args(__format_arg_store<_Context, _Args...>) -> basic_format_args<_Context>;
7306c3fb27SDimitry Andric 
7406c3fb27SDimitry Andric #endif //_LIBCPP_STD_VER >= 20
75349cc55cSDimitry Andric 
76349cc55cSDimitry Andric _LIBCPP_END_NAMESPACE_STD
77349cc55cSDimitry Andric 
78349cc55cSDimitry Andric #endif // _LIBCPP___FORMAT_FORMAT_ARGS_H
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