114 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			114 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C++
		
	
	
	
| // -*- C++ -*-
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| //===----------------------------------------------------------------------===//
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| //
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| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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| // See https://llvm.org/LICENSE.txt for license information.
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| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #ifndef _LIBCPP___FORMAT_FORMAT_PARSE_CONTEXT_H
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| #define _LIBCPP___FORMAT_FORMAT_PARSE_CONTEXT_H
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| 
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| #include <__config>
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| #include <__format/format_error.h>
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| #include <string_view>
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| 
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| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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| #pragma GCC system_header
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| #endif
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| 
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| _LIBCPP_PUSH_MACROS
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| #include <__undef_macros>
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| 
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| _LIBCPP_BEGIN_NAMESPACE_STD
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| 
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| #if _LIBCPP_STD_VER > 17
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| 
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| // TODO FMT Remove this once we require compilers with proper C++20 support.
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| // If the compiler has no concepts support, the format header will be disabled.
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| // Without concepts support enable_if needs to be used and that too much effort
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| // to support compilers with partial C++20 support.
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| #if !defined(_LIBCPP_HAS_NO_CONCEPTS) &&                                       \
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|     !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
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| 
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| template <class _CharT>
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| class _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FORMAT basic_format_parse_context {
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| public:
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|   using char_type = _CharT;
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|   using const_iterator = typename basic_string_view<_CharT>::const_iterator;
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|   using iterator = const_iterator;
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| 
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|   _LIBCPP_INLINE_VISIBILITY
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|   constexpr explicit basic_format_parse_context(basic_string_view<_CharT> __fmt,
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|                                                 size_t __num_args = 0) noexcept
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|       : __begin_(__fmt.begin()),
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|         __end_(__fmt.end()),
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|         __indexing_(__unknown),
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|         __next_arg_id_(0),
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|         __num_args_(__num_args) {}
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| 
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|   basic_format_parse_context(const basic_format_parse_context&) = delete;
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|   basic_format_parse_context&
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|   operator=(const basic_format_parse_context&) = delete;
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| 
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|   _LIBCPP_INLINE_VISIBILITY constexpr const_iterator begin() const noexcept {
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|     return __begin_;
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|   }
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|   _LIBCPP_INLINE_VISIBILITY constexpr const_iterator end() const noexcept {
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|     return __end_;
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|   }
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|   _LIBCPP_INLINE_VISIBILITY constexpr void advance_to(const_iterator __it) {
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|     __begin_ = __it;
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|   }
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| 
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|   _LIBCPP_INLINE_VISIBILITY constexpr size_t next_arg_id() {
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|     if (__indexing_ == __manual)
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|       __throw_format_error("Using automatic argument numbering in manual "
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|                            "argument numbering mode");
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| 
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|     if (__indexing_ == __unknown)
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|       __indexing_ = __automatic;
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|     return __next_arg_id_++;
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|   }
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|   _LIBCPP_INLINE_VISIBILITY constexpr void check_arg_id(size_t __id) {
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|     if (__indexing_ == __automatic)
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|       __throw_format_error("Using manual argument numbering in automatic "
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|                            "argument numbering mode");
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| 
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|     if (__indexing_ == __unknown)
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|       __indexing_ = __manual;
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| 
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|     // Throws an exception to make the expression a non core constant
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|     // expression as required by:
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|     // [format.parse.ctx]/11
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|     //   Remarks: Call expressions where id >= num_args_ are not core constant
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|     //   expressions ([expr.const]).
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|     // Note: the Throws clause [format.parse.ctx]/10 doesn't specify the
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|     // behavior when id >= num_args_.
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|     if (is_constant_evaluated() && __id >= __num_args_)
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|       __throw_format_error("Argument index outside the valid range");
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|   }
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| 
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| private:
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|   iterator __begin_;
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|   iterator __end_;
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|   enum _Indexing { __unknown, __manual, __automatic };
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|   _Indexing __indexing_;
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|   size_t __next_arg_id_;
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|   size_t __num_args_;
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| };
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| 
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| using format_parse_context = basic_format_parse_context<char>;
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| using wformat_parse_context = basic_format_parse_context<wchar_t>;
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| 
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| #endif // !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
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| 
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| #endif //_LIBCPP_STD_VER > 17
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| 
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| _LIBCPP_END_NAMESPACE_STD
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| 
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| _LIBCPP_POP_MACROS
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| 
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| #endif // _LIBCPP___FORMAT_FORMAT_PARSE_CONTEXT_H
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