1818 lines
50 KiB
C++
1818 lines
50 KiB
C++
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//
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// span for C++98 and later.
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// Based on http://wg21.link/p0122r7
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// For more information see https://github.com/martinmoene/span-lite
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//
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// Copyright 2018-2020 Martin Moene
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//
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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#ifndef NONSTD_SPAN_HPP_INCLUDED
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#define NONSTD_SPAN_HPP_INCLUDED
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#define span_lite_MAJOR 0
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#define span_lite_MINOR 9
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#define span_lite_PATCH 2
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#define span_lite_VERSION span_STRINGIFY(span_lite_MAJOR) "." span_STRINGIFY(span_lite_MINOR) "." span_STRINGIFY(span_lite_PATCH)
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#define span_STRINGIFY( x ) span_STRINGIFY_( x )
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#define span_STRINGIFY_( x ) #x
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// span configuration:
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#define span_SPAN_DEFAULT 0
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#define span_SPAN_NONSTD 1
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#define span_SPAN_STD 2
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// tweak header support:
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#ifdef __has_include
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# if __has_include(<nonstd/span.tweak.hpp>)
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# include <nonstd/span.tweak.hpp>
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# endif
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#define span_HAVE_TWEAK_HEADER 1
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#else
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#define span_HAVE_TWEAK_HEADER 0
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//# pragma message("span.hpp: Note: Tweak header not supported.")
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#endif
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// span selection and configuration:
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#define span_HAVE( feature ) ( span_HAVE_##feature )
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#ifndef span_CONFIG_SELECT_SPAN
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# define span_CONFIG_SELECT_SPAN ( span_HAVE_STD_SPAN ? span_SPAN_STD : span_SPAN_NONSTD )
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#endif
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#ifndef span_CONFIG_EXTENT_TYPE
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# define span_CONFIG_EXTENT_TYPE std::size_t
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#endif
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#ifndef span_CONFIG_SIZE_TYPE
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# define span_CONFIG_SIZE_TYPE std::size_t
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#endif
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#ifdef span_CONFIG_INDEX_TYPE
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# error `span_CONFIG_INDEX_TYPE` is deprecated since v0.7.0; it is replaced by `span_CONFIG_SIZE_TYPE`.
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#endif
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// span configuration (features):
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#ifndef span_FEATURE_WITH_CONTAINER
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#ifdef span_FEATURE_WITH_CONTAINER_TO_STD
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# define span_FEATURE_WITH_CONTAINER span_IN_STD( span_FEATURE_WITH_CONTAINER_TO_STD )
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#else
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# define span_FEATURE_WITH_CONTAINER 0
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#endif
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#endif
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#ifndef span_FEATURE_CONSTRUCTION_FROM_STDARRAY_ELEMENT_TYPE
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# define span_FEATURE_CONSTRUCTION_FROM_STDARRAY_ELEMENT_TYPE 0
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#endif
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#ifndef span_FEATURE_MEMBER_AT
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# define span_FEATURE_MEMBER_AT 0
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#endif
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#ifndef span_FEATURE_MEMBER_BACK_FRONT
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# define span_FEATURE_MEMBER_BACK_FRONT 1
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#endif
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#ifndef span_FEATURE_MEMBER_CALL_OPERATOR
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# define span_FEATURE_MEMBER_CALL_OPERATOR 0
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#endif
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#ifndef span_FEATURE_MEMBER_SWAP
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# define span_FEATURE_MEMBER_SWAP 0
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#endif
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#ifndef span_FEATURE_NON_MEMBER_FIRST_LAST_SUB
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# define span_FEATURE_NON_MEMBER_FIRST_LAST_SUB 0
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#endif
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#ifndef span_FEATURE_COMPARISON
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# define span_FEATURE_COMPARISON 0 // Note: C++20 does not provide comparison
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#endif
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#ifndef span_FEATURE_SAME
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# define span_FEATURE_SAME 0
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#endif
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#if span_FEATURE_SAME && !span_FEATURE_COMPARISON
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# error `span_FEATURE_SAME` requires `span_FEATURE_COMPARISON`
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#endif
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#ifndef span_FEATURE_MAKE_SPAN
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#ifdef span_FEATURE_MAKE_SPAN_TO_STD
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# define span_FEATURE_MAKE_SPAN span_IN_STD( span_FEATURE_MAKE_SPAN_TO_STD )
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#else
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# define span_FEATURE_MAKE_SPAN 0
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#endif
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#endif
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#ifndef span_FEATURE_BYTE_SPAN
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# define span_FEATURE_BYTE_SPAN 0
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#endif
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// Control presence of exception handling (try and auto discover):
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#ifndef span_CONFIG_NO_EXCEPTIONS
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# if _MSC_VER
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# include <cstddef> // for _HAS_EXCEPTIONS
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# endif
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# if defined(__cpp_exceptions) || defined(__EXCEPTIONS) || (_HAS_EXCEPTIONS)
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# define span_CONFIG_NO_EXCEPTIONS 0
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# else
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# define span_CONFIG_NO_EXCEPTIONS 1
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# undef span_CONFIG_CONTRACT_VIOLATION_THROWS
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# undef span_CONFIG_CONTRACT_VIOLATION_TERMINATES
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# define span_CONFIG_CONTRACT_VIOLATION_THROWS 0
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# define span_CONFIG_CONTRACT_VIOLATION_TERMINATES 1
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# endif
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#endif
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// Control pre- and postcondition violation behaviour:
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#if defined( span_CONFIG_CONTRACT_LEVEL_ON )
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# define span_CONFIG_CONTRACT_LEVEL_MASK 0x11
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#elif defined( span_CONFIG_CONTRACT_LEVEL_OFF )
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# define span_CONFIG_CONTRACT_LEVEL_MASK 0x00
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#elif defined( span_CONFIG_CONTRACT_LEVEL_EXPECTS_ONLY )
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# define span_CONFIG_CONTRACT_LEVEL_MASK 0x01
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#elif defined( span_CONFIG_CONTRACT_LEVEL_ENSURES_ONLY )
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# define span_CONFIG_CONTRACT_LEVEL_MASK 0x10
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#else
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# define span_CONFIG_CONTRACT_LEVEL_MASK 0x11
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#endif
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#if defined( span_CONFIG_CONTRACT_VIOLATION_THROWS )
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# define span_CONFIG_CONTRACT_VIOLATION_THROWS_V span_CONFIG_CONTRACT_VIOLATION_THROWS
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#else
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# define span_CONFIG_CONTRACT_VIOLATION_THROWS_V 0
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#endif
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#if defined( span_CONFIG_CONTRACT_VIOLATION_THROWS ) && span_CONFIG_CONTRACT_VIOLATION_THROWS && \
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defined( span_CONFIG_CONTRACT_VIOLATION_TERMINATES ) && span_CONFIG_CONTRACT_VIOLATION_TERMINATES
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# error Please define none or one of span_CONFIG_CONTRACT_VIOLATION_THROWS and span_CONFIG_CONTRACT_VIOLATION_TERMINATES to 1, but not both.
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#endif
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// C++ language version detection (C++20 is speculative):
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// Note: VC14.0/1900 (VS2015) lacks too much from C++14.
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#ifndef span_CPLUSPLUS
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# if defined(_MSVC_LANG ) && !defined(__clang__)
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# define span_CPLUSPLUS (_MSC_VER == 1900 ? 201103L : _MSVC_LANG )
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# else
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# define span_CPLUSPLUS __cplusplus
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# endif
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#endif
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#define span_CPP98_OR_GREATER ( span_CPLUSPLUS >= 199711L )
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#define span_CPP11_OR_GREATER ( span_CPLUSPLUS >= 201103L )
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#define span_CPP14_OR_GREATER ( span_CPLUSPLUS >= 201402L )
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#define span_CPP17_OR_GREATER ( span_CPLUSPLUS >= 201703L )
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#define span_CPP20_OR_GREATER ( span_CPLUSPLUS >= 202000L )
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// C++ language version (represent 98 as 3):
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#define span_CPLUSPLUS_V ( span_CPLUSPLUS / 100 - (span_CPLUSPLUS > 200000 ? 2000 : 1994) )
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#define span_IN_STD( v ) ( ((v) == 98 ? 3 : (v)) >= span_CPLUSPLUS_V )
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#define span_CONFIG( feature ) ( span_CONFIG_##feature )
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#define span_FEATURE( feature ) ( span_FEATURE_##feature )
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#define span_FEATURE_TO_STD( feature ) ( span_IN_STD( span_FEATURE( feature##_TO_STD ) ) )
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// Use C++20 std::span if available and requested:
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#if span_CPP20_OR_GREATER && defined(__has_include )
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# if __has_include( <span> )
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# define span_HAVE_STD_SPAN 1
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# else
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# define span_HAVE_STD_SPAN 0
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# endif
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#else
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# define span_HAVE_STD_SPAN 0
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#endif
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#define span_USES_STD_SPAN ( (span_CONFIG_SELECT_SPAN == span_SPAN_STD) || ((span_CONFIG_SELECT_SPAN == span_SPAN_DEFAULT) && span_HAVE_STD_SPAN) )
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//
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// Use C++20 std::span:
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//
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#if span_USES_STD_SPAN
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#include <span>
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namespace nonstd {
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using std::span;
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// Note: C++20 does not provide comparison
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// using std::operator==;
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// using std::operator!=;
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// using std::operator<;
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// using std::operator<=;
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// using std::operator>;
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// using std::operator>=;
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} // namespace nonstd
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#else // span_USES_STD_SPAN
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#include <algorithm>
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// Compiler versions:
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//
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// MSVC++ 6.0 _MSC_VER == 1200 span_COMPILER_MSVC_VERSION == 60 (Visual Studio 6.0)
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// MSVC++ 7.0 _MSC_VER == 1300 span_COMPILER_MSVC_VERSION == 70 (Visual Studio .NET 2002)
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// MSVC++ 7.1 _MSC_VER == 1310 span_COMPILER_MSVC_VERSION == 71 (Visual Studio .NET 2003)
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// MSVC++ 8.0 _MSC_VER == 1400 span_COMPILER_MSVC_VERSION == 80 (Visual Studio 2005)
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// MSVC++ 9.0 _MSC_VER == 1500 span_COMPILER_MSVC_VERSION == 90 (Visual Studio 2008)
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// MSVC++ 10.0 _MSC_VER == 1600 span_COMPILER_MSVC_VERSION == 100 (Visual Studio 2010)
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// MSVC++ 11.0 _MSC_VER == 1700 span_COMPILER_MSVC_VERSION == 110 (Visual Studio 2012)
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// MSVC++ 12.0 _MSC_VER == 1800 span_COMPILER_MSVC_VERSION == 120 (Visual Studio 2013)
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// MSVC++ 14.0 _MSC_VER == 1900 span_COMPILER_MSVC_VERSION == 140 (Visual Studio 2015)
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// MSVC++ 14.1 _MSC_VER >= 1910 span_COMPILER_MSVC_VERSION == 141 (Visual Studio 2017)
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// MSVC++ 14.2 _MSC_VER >= 1920 span_COMPILER_MSVC_VERSION == 142 (Visual Studio 2019)
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#if defined(_MSC_VER ) && !defined(__clang__)
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# define span_COMPILER_MSVC_VER (_MSC_VER )
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# define span_COMPILER_MSVC_VERSION (_MSC_VER / 10 - 10 * ( 5 + (_MSC_VER < 1900 ) ) )
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#else
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# define span_COMPILER_MSVC_VER 0
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# define span_COMPILER_MSVC_VERSION 0
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#endif
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#define span_COMPILER_VERSION( major, minor, patch ) ( 10 * ( 10 * (major) + (minor) ) + (patch) )
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#if defined(__clang__)
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# define span_COMPILER_CLANG_VERSION span_COMPILER_VERSION(__clang_major__, __clang_minor__, __clang_patchlevel__)
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#else
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# define span_COMPILER_CLANG_VERSION 0
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#endif
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#if defined(__GNUC__) && !defined(__clang__)
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# define span_COMPILER_GNUC_VERSION span_COMPILER_VERSION(__GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__)
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#else
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# define span_COMPILER_GNUC_VERSION 0
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#endif
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// half-open range [lo..hi):
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#define span_BETWEEN( v, lo, hi ) ( (lo) <= (v) && (v) < (hi) )
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// Compiler warning suppression:
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#if defined(__clang__)
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# pragma clang diagnostic push
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|||
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# pragma clang diagnostic ignored "-Wundef"
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|||
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# pragma clang diagnostic ignored "-Wmismatched-tags"
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|||
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# define span_RESTORE_WARNINGS() _Pragma( "clang diagnostic pop" )
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#elif defined __GNUC__
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# pragma GCC diagnostic push
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|||
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# pragma GCC diagnostic ignored "-Wundef"
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# define span_RESTORE_WARNINGS() _Pragma( "GCC diagnostic pop" )
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#elif span_COMPILER_MSVC_VER >= 1900
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# define span_DISABLE_MSVC_WARNINGS(codes) __pragma(warning(push)) __pragma(warning(disable: codes))
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# define span_RESTORE_WARNINGS() __pragma(warning(pop ))
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|||
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// Suppress the following MSVC GSL warnings:
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|||
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// - C26439, gsl::f.6 : special function 'function' can be declared 'noexcept'
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|||
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// - C26440, gsl::f.6 : function 'function' can be declared 'noexcept'
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|||
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// - C26472, gsl::t.1 : don't use a static_cast for arithmetic conversions;
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|||
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// use brace initialization, gsl::narrow_cast or gsl::narrow
|
|||
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// - C26473: gsl::t.1 : don't cast between pointer types where the source type and the target type are the same
|
|||
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// - C26481: gsl::b.1 : don't use pointer arithmetic. Use span instead
|
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// - C26490: gsl::t.1 : don't use reinterpret_cast
|
|||
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span_DISABLE_MSVC_WARNINGS( 26439 26440 26472 26473 26481 26490 )
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|||
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#else
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|||
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# define span_RESTORE_WARNINGS() /*empty*/
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|||
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#endif
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|||
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|||
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// Presence of language and library features:
|
|||
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|||
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#ifdef _HAS_CPP0X
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|||
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# define span_HAS_CPP0X _HAS_CPP0X
|
|||
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#else
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|||
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# define span_HAS_CPP0X 0
|
|||
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#endif
|
|||
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#define span_CPP11_80 (span_CPP11_OR_GREATER || span_COMPILER_MSVC_VER >= 1400)
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|||
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#define span_CPP11_90 (span_CPP11_OR_GREATER || span_COMPILER_MSVC_VER >= 1500)
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|||
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#define span_CPP11_100 (span_CPP11_OR_GREATER || span_COMPILER_MSVC_VER >= 1600)
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|||
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#define span_CPP11_110 (span_CPP11_OR_GREATER || span_COMPILER_MSVC_VER >= 1700)
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|||
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#define span_CPP11_120 (span_CPP11_OR_GREATER || span_COMPILER_MSVC_VER >= 1800)
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|||
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#define span_CPP11_140 (span_CPP11_OR_GREATER || span_COMPILER_MSVC_VER >= 1900)
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|||
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#define span_CPP14_000 (span_CPP14_OR_GREATER)
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|||
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#define span_CPP14_120 (span_CPP14_OR_GREATER || span_COMPILER_MSVC_VER >= 1800)
|
|||
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#define span_CPP14_140 (span_CPP14_OR_GREATER || span_COMPILER_MSVC_VER >= 1900)
|
|||
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|||
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#define span_CPP17_000 (span_CPP17_OR_GREATER)
|
|||
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|||
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// Presence of C++11 language features:
|
|||
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|||
|
|
#define span_HAVE_ALIAS_TEMPLATE span_CPP11_140
|
|||
|
|
#define span_HAVE_AUTO span_CPP11_100
|
|||
|
|
#define span_HAVE_CONSTEXPR_11 span_CPP11_140
|
|||
|
|
#define span_HAVE_DEFAULT_FUNCTION_TEMPLATE_ARG span_CPP11_120
|
|||
|
|
#define span_HAVE_EXPLICIT_CONVERSION span_CPP11_140
|
|||
|
|
#define span_HAVE_INITIALIZER_LIST span_CPP11_120
|
|||
|
|
#define span_HAVE_IS_DEFAULT span_CPP11_140
|
|||
|
|
#define span_HAVE_IS_DELETE span_CPP11_140
|
|||
|
|
#define span_HAVE_NOEXCEPT span_CPP11_140
|
|||
|
|
#define span_HAVE_NULLPTR span_CPP11_100
|
|||
|
|
#define span_HAVE_STATIC_ASSERT span_CPP11_100
|
|||
|
|
|
|||
|
|
// Presence of C++14 language features:
|
|||
|
|
|
|||
|
|
#define span_HAVE_CONSTEXPR_14 span_CPP14_000
|
|||
|
|
|
|||
|
|
// Presence of C++17 language features:
|
|||
|
|
|
|||
|
|
#define span_HAVE_DEPRECATED span_CPP17_000
|
|||
|
|
#define span_HAVE_NODISCARD span_CPP17_000
|
|||
|
|
#define span_HAVE_NORETURN span_CPP17_000
|
|||
|
|
|
|||
|
|
// MSVC: template parameter deduction guides since Visual Studio 2017 v15.7
|
|||
|
|
|
|||
|
|
#if defined(__cpp_deduction_guides)
|
|||
|
|
# define span_HAVE_DEDUCTION_GUIDES 1
|
|||
|
|
#else
|
|||
|
|
# define span_HAVE_DEDUCTION_GUIDES (span_CPP17_OR_GREATER && ! span_BETWEEN( span_COMPILER_MSVC_VER, 1, 1913 ))
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
// Presence of C++ library features:
|
|||
|
|
|
|||
|
|
#define span_HAVE_ADDRESSOF span_CPP17_000
|
|||
|
|
#define span_HAVE_ARRAY span_CPP11_110
|
|||
|
|
#define span_HAVE_BYTE span_CPP17_000
|
|||
|
|
#define span_HAVE_CONDITIONAL span_CPP11_120
|
|||
|
|
#define span_HAVE_CONTAINER_DATA_METHOD (span_CPP11_140 || ( span_COMPILER_MSVC_VER >= 1500 && span_HAS_CPP0X ))
|
|||
|
|
#define span_HAVE_DATA span_CPP17_000
|
|||
|
|
#define span_HAVE_LONGLONG span_CPP11_80
|
|||
|
|
#define span_HAVE_REMOVE_CONST span_CPP11_110
|
|||
|
|
#define span_HAVE_SNPRINTF span_CPP11_140
|
|||
|
|
#define span_HAVE_STRUCT_BINDING span_CPP11_120
|
|||
|
|
#define span_HAVE_TYPE_TRAITS span_CPP11_90
|
|||
|
|
|
|||
|
|
// Presence of byte-lite:
|
|||
|
|
|
|||
|
|
#ifdef NONSTD_BYTE_LITE_HPP
|
|||
|
|
# define span_HAVE_NONSTD_BYTE 1
|
|||
|
|
#else
|
|||
|
|
# define span_HAVE_NONSTD_BYTE 0
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
// C++ feature usage:
|
|||
|
|
|
|||
|
|
#if span_HAVE_ADDRESSOF
|
|||
|
|
# define span_ADDRESSOF(x) std::addressof(x)
|
|||
|
|
#else
|
|||
|
|
# define span_ADDRESSOF(x) (&x)
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE_CONSTEXPR_11
|
|||
|
|
# define span_constexpr constexpr
|
|||
|
|
#else
|
|||
|
|
# define span_constexpr /*span_constexpr*/
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE_CONSTEXPR_14
|
|||
|
|
# define span_constexpr14 constexpr
|
|||
|
|
#else
|
|||
|
|
# define span_constexpr14 /*span_constexpr*/
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE_EXPLICIT_CONVERSION
|
|||
|
|
# define span_explicit explicit
|
|||
|
|
#else
|
|||
|
|
# define span_explicit /*explicit*/
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE_IS_DELETE
|
|||
|
|
# define span_is_delete = delete
|
|||
|
|
#else
|
|||
|
|
# define span_is_delete
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE_IS_DELETE
|
|||
|
|
# define span_is_delete_access public
|
|||
|
|
#else
|
|||
|
|
# define span_is_delete_access private
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE_NOEXCEPT && ! span_CONFIG_CONTRACT_VIOLATION_THROWS_V
|
|||
|
|
# define span_noexcept noexcept
|
|||
|
|
#else
|
|||
|
|
# define span_noexcept /*noexcept*/
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE_NULLPTR
|
|||
|
|
# define span_nullptr nullptr
|
|||
|
|
#else
|
|||
|
|
# define span_nullptr NULL
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE_DEPRECATED
|
|||
|
|
# define span_deprecated(msg) [[deprecated(msg)]]
|
|||
|
|
#else
|
|||
|
|
# define span_deprecated(msg) /*[[deprecated]]*/
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE_NODISCARD
|
|||
|
|
# define span_nodiscard [[nodiscard]]
|
|||
|
|
#else
|
|||
|
|
# define span_nodiscard /*[[nodiscard]]*/
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE_NORETURN
|
|||
|
|
# define span_noreturn [[noreturn]]
|
|||
|
|
#else
|
|||
|
|
# define span_noreturn /*[[noreturn]]*/
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
// Other features:
|
|||
|
|
|
|||
|
|
#define span_HAVE_CONSTRAINED_SPAN_CONTAINER_CTOR span_HAVE_DEFAULT_FUNCTION_TEMPLATE_ARG
|
|||
|
|
#define span_HAVE_ITERATOR_CTOR span_HAVE_DEFAULT_FUNCTION_TEMPLATE_ARG
|
|||
|
|
|
|||
|
|
// Additional includes:
|
|||
|
|
|
|||
|
|
#if span_HAVE( ADDRESSOF )
|
|||
|
|
# include <memory>
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE( ARRAY )
|
|||
|
|
# include <array>
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE( BYTE )
|
|||
|
|
# include <cstddef>
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE( DATA )
|
|||
|
|
# include <iterator> // for std::data(), std::size()
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE( TYPE_TRAITS )
|
|||
|
|
# include <type_traits>
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if ! span_HAVE( CONSTRAINED_SPAN_CONTAINER_CTOR )
|
|||
|
|
# include <vector>
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_FEATURE( MEMBER_AT ) > 1
|
|||
|
|
# include <cstdio>
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if ! span_CONFIG( NO_EXCEPTIONS )
|
|||
|
|
# include <stdexcept>
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
// Contract violation
|
|||
|
|
|
|||
|
|
#define span_ELIDE_CONTRACT_EXPECTS ( 0 == ( span_CONFIG_CONTRACT_LEVEL_MASK & 0x01 ) )
|
|||
|
|
#define span_ELIDE_CONTRACT_ENSURES ( 0 == ( span_CONFIG_CONTRACT_LEVEL_MASK & 0x10 ) )
|
|||
|
|
|
|||
|
|
#if span_ELIDE_CONTRACT_EXPECTS
|
|||
|
|
# define span_constexpr_exp span_constexpr
|
|||
|
|
# define span_EXPECTS( cond ) /* Expect elided */
|
|||
|
|
#else
|
|||
|
|
# define span_constexpr_exp span_constexpr14
|
|||
|
|
# define span_EXPECTS( cond ) span_CONTRACT_CHECK( "Precondition", cond )
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_ELIDE_CONTRACT_ENSURES
|
|||
|
|
# define span_constexpr_ens span_constexpr
|
|||
|
|
# define span_ENSURES( cond ) /* Ensures elided */
|
|||
|
|
#else
|
|||
|
|
# define span_constexpr_ens span_constexpr14
|
|||
|
|
# define span_ENSURES( cond ) span_CONTRACT_CHECK( "Postcondition", cond )
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#define span_CONTRACT_CHECK( type, cond ) \
|
|||
|
|
cond ? static_cast< void >( 0 ) \
|
|||
|
|
: nonstd::span_lite::detail::report_contract_violation( span_LOCATION( __FILE__, __LINE__ ) ": " type " violation." )
|
|||
|
|
|
|||
|
|
#ifdef __GNUG__
|
|||
|
|
# define span_LOCATION( file, line ) file ":" span_STRINGIFY( line )
|
|||
|
|
#else
|
|||
|
|
# define span_LOCATION( file, line ) file "(" span_STRINGIFY( line ) ")"
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
// Method enabling
|
|||
|
|
|
|||
|
|
#if span_HAVE( DEFAULT_FUNCTION_TEMPLATE_ARG )
|
|||
|
|
|
|||
|
|
#define span_REQUIRES_0(VA) \
|
|||
|
|
template< bool B = (VA), typename std::enable_if<B, int>::type = 0 >
|
|||
|
|
|
|||
|
|
# if span_BETWEEN( span_COMPILER_MSVC_VERSION, 1, 140 )
|
|||
|
|
// VS 2013 and earlier seem to have trouble with SFINAE for default non-type arguments
|
|||
|
|
# define span_REQUIRES_T(VA) \
|
|||
|
|
, typename = typename std::enable_if< ( VA ), nonstd::span_lite::detail::enabler >::type
|
|||
|
|
# else
|
|||
|
|
# define span_REQUIRES_T(VA) \
|
|||
|
|
, typename std::enable_if< (VA), int >::type = 0
|
|||
|
|
# endif
|
|||
|
|
|
|||
|
|
#define span_REQUIRES_R(R, VA) \
|
|||
|
|
typename std::enable_if< (VA), R>::type
|
|||
|
|
|
|||
|
|
#define span_REQUIRES_A(VA) \
|
|||
|
|
, typename std::enable_if< (VA), void*>::type = nullptr
|
|||
|
|
|
|||
|
|
#else
|
|||
|
|
|
|||
|
|
# define span_REQUIRES_0(VA) /*empty*/
|
|||
|
|
# define span_REQUIRES_T(VA) /*empty*/
|
|||
|
|
# define span_REQUIRES_R(R, VA) R
|
|||
|
|
# define span_REQUIRES_A(VA) /*empty*/
|
|||
|
|
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
namespace nonstd {
|
|||
|
|
namespace span_lite {
|
|||
|
|
|
|||
|
|
// [views.constants], constants
|
|||
|
|
|
|||
|
|
typedef span_CONFIG_EXTENT_TYPE extent_t;
|
|||
|
|
typedef span_CONFIG_SIZE_TYPE size_t;
|
|||
|
|
|
|||
|
|
span_constexpr const extent_t dynamic_extent = static_cast<extent_t>( -1 );
|
|||
|
|
|
|||
|
|
template< class T, extent_t Extent = dynamic_extent >
|
|||
|
|
class span;
|
|||
|
|
|
|||
|
|
// Tag to select span constructor taking a container (prevent ms-gsl warning C26426):
|
|||
|
|
|
|||
|
|
struct with_container_t { span_constexpr with_container_t() span_noexcept {} };
|
|||
|
|
const span_constexpr with_container_t with_container;
|
|||
|
|
|
|||
|
|
// C++11 emulation:
|
|||
|
|
|
|||
|
|
namespace std11 {
|
|||
|
|
|
|||
|
|
#if span_HAVE( REMOVE_CONST )
|
|||
|
|
|
|||
|
|
using std::remove_cv;
|
|||
|
|
using std::remove_const;
|
|||
|
|
using std::remove_volatile;
|
|||
|
|
|
|||
|
|
#else
|
|||
|
|
|
|||
|
|
template< class T > struct remove_const { typedef T type; };
|
|||
|
|
template< class T > struct remove_const< T const > { typedef T type; };
|
|||
|
|
|
|||
|
|
template< class T > struct remove_volatile { typedef T type; };
|
|||
|
|
template< class T > struct remove_volatile< T volatile > { typedef T type; };
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
struct remove_cv
|
|||
|
|
{
|
|||
|
|
typedef typename std11::remove_volatile< typename std11::remove_const< T >::type >::type type;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
#endif // span_HAVE( REMOVE_CONST )
|
|||
|
|
|
|||
|
|
#if span_HAVE( TYPE_TRAITS )
|
|||
|
|
|
|||
|
|
using std::is_same;
|
|||
|
|
using std::is_signed;
|
|||
|
|
using std::integral_constant;
|
|||
|
|
using std::true_type;
|
|||
|
|
using std::false_type;
|
|||
|
|
using std::remove_reference;
|
|||
|
|
|
|||
|
|
#else
|
|||
|
|
|
|||
|
|
template< class T, T v > struct integral_constant { enum { value = v }; };
|
|||
|
|
typedef integral_constant< bool, true > true_type;
|
|||
|
|
typedef integral_constant< bool, false > false_type;
|
|||
|
|
|
|||
|
|
template< class T, class U > struct is_same : false_type{};
|
|||
|
|
template< class T > struct is_same<T, T> : true_type{};
|
|||
|
|
|
|||
|
|
template< typename T > struct is_signed : false_type {};
|
|||
|
|
template<> struct is_signed<signed char> : true_type {};
|
|||
|
|
template<> struct is_signed<signed int > : true_type {};
|
|||
|
|
template<> struct is_signed<signed long> : true_type {};
|
|||
|
|
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
} // namespace std11
|
|||
|
|
|
|||
|
|
// C++17 emulation:
|
|||
|
|
|
|||
|
|
namespace std17 {
|
|||
|
|
|
|||
|
|
template< bool v > struct bool_constant : std11::integral_constant<bool, v>{};
|
|||
|
|
|
|||
|
|
#if span_CPP11_120
|
|||
|
|
|
|||
|
|
template< class...>
|
|||
|
|
using void_t = void;
|
|||
|
|
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE( DATA )
|
|||
|
|
|
|||
|
|
using std::data;
|
|||
|
|
using std::size;
|
|||
|
|
|
|||
|
|
#elif span_HAVE( CONSTRAINED_SPAN_CONTAINER_CTOR )
|
|||
|
|
|
|||
|
|
template< typename T, std::size_t N >
|
|||
|
|
inline span_constexpr auto size( const T(&)[N] ) span_noexcept -> size_t
|
|||
|
|
{
|
|||
|
|
return N;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< typename C >
|
|||
|
|
inline span_constexpr auto size( C const & cont ) -> decltype( cont.size() )
|
|||
|
|
{
|
|||
|
|
return cont.size();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< typename T, std::size_t N >
|
|||
|
|
inline span_constexpr auto data( T(&arr)[N] ) span_noexcept -> T*
|
|||
|
|
{
|
|||
|
|
return &arr[0];
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< typename C >
|
|||
|
|
inline span_constexpr auto data( C & cont ) -> decltype( cont.data() )
|
|||
|
|
{
|
|||
|
|
return cont.data();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< typename C >
|
|||
|
|
inline span_constexpr auto data( C const & cont ) -> decltype( cont.data() )
|
|||
|
|
{
|
|||
|
|
return cont.data();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< typename E >
|
|||
|
|
inline span_constexpr auto data( std::initializer_list<E> il ) span_noexcept -> E const *
|
|||
|
|
{
|
|||
|
|
return il.begin();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#endif // span_HAVE( DATA )
|
|||
|
|
|
|||
|
|
#if span_HAVE( BYTE )
|
|||
|
|
using std::byte;
|
|||
|
|
#elif span_HAVE( NONSTD_BYTE )
|
|||
|
|
using nonstd::byte;
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
} // namespace std17
|
|||
|
|
|
|||
|
|
// C++20 emulation:
|
|||
|
|
|
|||
|
|
namespace std20 {
|
|||
|
|
|
|||
|
|
#if span_HAVE( DEDUCTION_GUIDES )
|
|||
|
|
template< class T >
|
|||
|
|
using iter_reference_t = decltype( *std::declval<T&>() );
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
} // namespace std20
|
|||
|
|
|
|||
|
|
// Implementation details:
|
|||
|
|
|
|||
|
|
namespace detail {
|
|||
|
|
|
|||
|
|
/*enum*/ struct enabler{};
|
|||
|
|
|
|||
|
|
template< typename T >
|
|||
|
|
bool is_positive( T x )
|
|||
|
|
{
|
|||
|
|
return std11::is_signed<T>::value ? x >= 0 : true;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#if span_HAVE( TYPE_TRAITS )
|
|||
|
|
|
|||
|
|
template< class Q >
|
|||
|
|
struct is_span_oracle : std::false_type{};
|
|||
|
|
|
|||
|
|
template< class T, span_CONFIG_EXTENT_TYPE Extent >
|
|||
|
|
struct is_span_oracle< span<T, Extent> > : std::true_type{};
|
|||
|
|
|
|||
|
|
template< class Q >
|
|||
|
|
struct is_span : is_span_oracle< typename std::remove_cv<Q>::type >{};
|
|||
|
|
|
|||
|
|
template< class Q >
|
|||
|
|
struct is_std_array_oracle : std::false_type{};
|
|||
|
|
|
|||
|
|
#if span_HAVE( ARRAY )
|
|||
|
|
|
|||
|
|
template< class T, std::size_t Extent >
|
|||
|
|
struct is_std_array_oracle< std::array<T, Extent> > : std::true_type{};
|
|||
|
|
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
template< class Q >
|
|||
|
|
struct is_std_array : is_std_array_oracle< typename std::remove_cv<Q>::type >{};
|
|||
|
|
|
|||
|
|
template< class Q >
|
|||
|
|
struct is_array : std::false_type {};
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
struct is_array<T[]> : std::true_type {};
|
|||
|
|
|
|||
|
|
template< class T, std::size_t N >
|
|||
|
|
struct is_array<T[N]> : std::true_type {};
|
|||
|
|
|
|||
|
|
#if span_CPP11_140 && ! span_BETWEEN( span_COMPILER_GNUC_VERSION, 1, 500 )
|
|||
|
|
|
|||
|
|
template< class, class = void >
|
|||
|
|
struct has_size_and_data : std::false_type{};
|
|||
|
|
|
|||
|
|
template< class C >
|
|||
|
|
struct has_size_and_data
|
|||
|
|
<
|
|||
|
|
C, std17::void_t<
|
|||
|
|
decltype( std17::size(std::declval<C>()) ),
|
|||
|
|
decltype( std17::data(std::declval<C>()) ) >
|
|||
|
|
> : std::true_type{};
|
|||
|
|
|
|||
|
|
template< class, class, class = void >
|
|||
|
|
struct is_compatible_element : std::false_type {};
|
|||
|
|
|
|||
|
|
template< class C, class E >
|
|||
|
|
struct is_compatible_element
|
|||
|
|
<
|
|||
|
|
C, E, std17::void_t<
|
|||
|
|
decltype( std17::data(std::declval<C>()) ) >
|
|||
|
|
> : std::is_convertible< typename std::remove_pointer<decltype( std17::data( std::declval<C&>() ) )>::type(*)[], E(*)[] >{};
|
|||
|
|
|
|||
|
|
template< class C >
|
|||
|
|
struct is_container : std17::bool_constant
|
|||
|
|
<
|
|||
|
|
! is_span< C >::value
|
|||
|
|
&& ! is_array< C >::value
|
|||
|
|
&& ! is_std_array< C >::value
|
|||
|
|
&& has_size_and_data< C >::value
|
|||
|
|
>{};
|
|||
|
|
|
|||
|
|
template< class C, class E >
|
|||
|
|
struct is_compatible_container : std17::bool_constant
|
|||
|
|
<
|
|||
|
|
is_container<C>::value
|
|||
|
|
&& is_compatible_element<C,E>::value
|
|||
|
|
>{};
|
|||
|
|
|
|||
|
|
#else // span_CPP11_140
|
|||
|
|
|
|||
|
|
template<
|
|||
|
|
class C, class E
|
|||
|
|
span_REQUIRES_T((
|
|||
|
|
! is_span< C >::value
|
|||
|
|
&& ! is_array< C >::value
|
|||
|
|
&& ! is_std_array< C >::value
|
|||
|
|
&& ( std::is_convertible< typename std::remove_pointer<decltype( std17::data( std::declval<C&>() ) )>::type(*)[], E(*)[] >::value)
|
|||
|
|
// && has_size_and_data< C >::value
|
|||
|
|
))
|
|||
|
|
, class = decltype( std17::size(std::declval<C>()) )
|
|||
|
|
, class = decltype( std17::data(std::declval<C>()) )
|
|||
|
|
>
|
|||
|
|
struct is_compatible_container : std::true_type{};
|
|||
|
|
|
|||
|
|
#endif // span_CPP11_140
|
|||
|
|
|
|||
|
|
#endif // span_HAVE( TYPE_TRAITS )
|
|||
|
|
|
|||
|
|
#if ! span_CONFIG( NO_EXCEPTIONS )
|
|||
|
|
#if span_FEATURE( MEMBER_AT ) > 1
|
|||
|
|
|
|||
|
|
// format index and size:
|
|||
|
|
|
|||
|
|
#if defined(__clang__)
|
|||
|
|
# pragma clang diagnostic ignored "-Wlong-long"
|
|||
|
|
#elif defined __GNUC__
|
|||
|
|
# pragma GCC diagnostic ignored "-Wformat=ll"
|
|||
|
|
# pragma GCC diagnostic ignored "-Wlong-long"
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
inline void throw_out_of_range( size_t idx, size_t size )
|
|||
|
|
{
|
|||
|
|
const char fmt[] = "span::at(): index '%lli' is out of range [0..%lli)";
|
|||
|
|
char buffer[ 2 * 20 + sizeof fmt ];
|
|||
|
|
sprintf( buffer, fmt, static_cast<long long>(idx), static_cast<long long>(size) );
|
|||
|
|
|
|||
|
|
throw std::out_of_range( buffer );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#else // MEMBER_AT
|
|||
|
|
|
|||
|
|
inline void throw_out_of_range( size_t /*idx*/, size_t /*size*/ )
|
|||
|
|
{
|
|||
|
|
throw std::out_of_range( "span::at(): index outside span" );
|
|||
|
|
}
|
|||
|
|
#endif // MEMBER_AT
|
|||
|
|
#endif // NO_EXCEPTIONS
|
|||
|
|
|
|||
|
|
#if span_CONFIG( CONTRACT_VIOLATION_THROWS_V )
|
|||
|
|
|
|||
|
|
struct contract_violation : std::logic_error
|
|||
|
|
{
|
|||
|
|
explicit contract_violation( char const * const message )
|
|||
|
|
: std::logic_error( message )
|
|||
|
|
{}
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
inline void report_contract_violation( char const * msg )
|
|||
|
|
{
|
|||
|
|
throw contract_violation( msg );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#else // span_CONFIG( CONTRACT_VIOLATION_THROWS_V )
|
|||
|
|
|
|||
|
|
span_noreturn inline void report_contract_violation( char const * /*msg*/ ) span_noexcept
|
|||
|
|
{
|
|||
|
|
std::terminate();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#endif // span_CONFIG( CONTRACT_VIOLATION_THROWS_V )
|
|||
|
|
|
|||
|
|
} // namespace detail
|
|||
|
|
|
|||
|
|
// Prevent signed-unsigned mismatch:
|
|||
|
|
|
|||
|
|
#define span_sizeof(T) static_cast<extent_t>( sizeof(T) )
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
inline span_constexpr size_t to_size( T size )
|
|||
|
|
{
|
|||
|
|
return static_cast<size_t>( size );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// [views.span] - A view over a contiguous, single-dimension sequence of objects
|
|||
|
|
//
|
|||
|
|
template< class T, extent_t Extent /*= dynamic_extent*/ >
|
|||
|
|
class span
|
|||
|
|
{
|
|||
|
|
public:
|
|||
|
|
// constants and types
|
|||
|
|
|
|||
|
|
typedef T element_type;
|
|||
|
|
typedef typename std11::remove_cv< T >::type value_type;
|
|||
|
|
|
|||
|
|
typedef T & reference;
|
|||
|
|
typedef T * pointer;
|
|||
|
|
typedef T const * const_pointer;
|
|||
|
|
typedef T const & const_reference;
|
|||
|
|
|
|||
|
|
typedef size_t size_type;
|
|||
|
|
typedef extent_t extent_type;
|
|||
|
|
|
|||
|
|
typedef pointer iterator;
|
|||
|
|
typedef const_pointer const_iterator;
|
|||
|
|
|
|||
|
|
typedef std::ptrdiff_t difference_type;
|
|||
|
|
|
|||
|
|
typedef std::reverse_iterator< iterator > reverse_iterator;
|
|||
|
|
typedef std::reverse_iterator< const_iterator > const_reverse_iterator;
|
|||
|
|
|
|||
|
|
// static constexpr extent_type extent = Extent;
|
|||
|
|
enum { extent = Extent };
|
|||
|
|
|
|||
|
|
// 26.7.3.2 Constructors, copy, and assignment [span.cons]
|
|||
|
|
|
|||
|
|
span_REQUIRES_0(
|
|||
|
|
( Extent == 0 ) ||
|
|||
|
|
( Extent == dynamic_extent )
|
|||
|
|
)
|
|||
|
|
span_constexpr span() span_noexcept
|
|||
|
|
: data_( span_nullptr )
|
|||
|
|
, size_( 0 )
|
|||
|
|
{
|
|||
|
|
// span_EXPECTS( data() == span_nullptr );
|
|||
|
|
// span_EXPECTS( size() == 0 );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#if span_HAVE( ITERATOR_CTOR )
|
|||
|
|
// Didn't yet succeed in combining the next two constructors:
|
|||
|
|
|
|||
|
|
span_constexpr_exp span( std::nullptr_t, size_type count )
|
|||
|
|
: data_( span_nullptr )
|
|||
|
|
, size_( count )
|
|||
|
|
{
|
|||
|
|
span_EXPECTS( data_ == span_nullptr && count == 0 );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< typename It
|
|||
|
|
span_REQUIRES_T((
|
|||
|
|
std::is_convertible<decltype(*std::declval<It&>()), element_type>::value
|
|||
|
|
))
|
|||
|
|
>
|
|||
|
|
span_constexpr_exp span( It first, size_type count )
|
|||
|
|
: data_( to_address( first ) )
|
|||
|
|
, size_( count )
|
|||
|
|
{
|
|||
|
|
span_EXPECTS(
|
|||
|
|
( data_ == span_nullptr && count == 0 ) ||
|
|||
|
|
( data_ != span_nullptr && detail::is_positive( count ) )
|
|||
|
|
);
|
|||
|
|
}
|
|||
|
|
#else
|
|||
|
|
span_constexpr_exp span( pointer ptr, size_type count )
|
|||
|
|
: data_( ptr )
|
|||
|
|
, size_( count )
|
|||
|
|
{
|
|||
|
|
span_EXPECTS(
|
|||
|
|
( ptr == span_nullptr && count == 0 ) ||
|
|||
|
|
( ptr != span_nullptr && detail::is_positive( count ) )
|
|||
|
|
);
|
|||
|
|
}
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE( ITERATOR_CTOR )
|
|||
|
|
template< typename It, typename End
|
|||
|
|
span_REQUIRES_T((
|
|||
|
|
std::is_convertible<decltype(*std::declval<It&>()), element_type>::value
|
|||
|
|
&& ! std::is_convertible<End, std::size_t>::value
|
|||
|
|
))
|
|||
|
|
>
|
|||
|
|
span_constexpr_exp span( It first, End last )
|
|||
|
|
: data_( to_address( first ) )
|
|||
|
|
, size_( to_size( last - first ) )
|
|||
|
|
{
|
|||
|
|
span_EXPECTS(
|
|||
|
|
last - first >= 0
|
|||
|
|
);
|
|||
|
|
}
|
|||
|
|
#else
|
|||
|
|
span_constexpr_exp span( pointer first, pointer last )
|
|||
|
|
: data_( first )
|
|||
|
|
, size_( to_size( last - first ) )
|
|||
|
|
{
|
|||
|
|
span_EXPECTS(
|
|||
|
|
last - first >= 0
|
|||
|
|
);
|
|||
|
|
}
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
template< std::size_t N
|
|||
|
|
span_REQUIRES_T((
|
|||
|
|
(Extent == dynamic_extent || Extent == static_cast<extent_t>(N))
|
|||
|
|
&& std::is_convertible< value_type(*)[], element_type(*)[] >::value
|
|||
|
|
))
|
|||
|
|
>
|
|||
|
|
span_constexpr span( element_type ( &arr )[ N ] ) span_noexcept
|
|||
|
|
: data_( span_ADDRESSOF( arr[0] ) )
|
|||
|
|
, size_( N )
|
|||
|
|
{}
|
|||
|
|
|
|||
|
|
#if span_HAVE( ARRAY )
|
|||
|
|
|
|||
|
|
template< std::size_t N
|
|||
|
|
span_REQUIRES_T((
|
|||
|
|
(Extent == dynamic_extent || Extent == static_cast<extent_t>(N))
|
|||
|
|
&& std::is_convertible< value_type(*)[], element_type(*)[] >::value
|
|||
|
|
))
|
|||
|
|
>
|
|||
|
|
# if span_FEATURE( CONSTRUCTION_FROM_STDARRAY_ELEMENT_TYPE )
|
|||
|
|
span_constexpr span( std::array< element_type, N > & arr ) span_noexcept
|
|||
|
|
# else
|
|||
|
|
span_constexpr span( std::array< value_type, N > & arr ) span_noexcept
|
|||
|
|
# endif
|
|||
|
|
: data_( arr.data() )
|
|||
|
|
, size_( to_size( arr.size() ) )
|
|||
|
|
{}
|
|||
|
|
|
|||
|
|
template< std::size_t N
|
|||
|
|
# if span_HAVE( DEFAULT_FUNCTION_TEMPLATE_ARG )
|
|||
|
|
span_REQUIRES_T((
|
|||
|
|
(Extent == dynamic_extent || Extent == static_cast<extent_t>(N))
|
|||
|
|
&& std::is_convertible< value_type(*)[], element_type(*)[] >::value
|
|||
|
|
))
|
|||
|
|
# endif
|
|||
|
|
>
|
|||
|
|
span_constexpr span( std::array< value_type, N> const & arr ) span_noexcept
|
|||
|
|
: data_( arr.data() )
|
|||
|
|
, size_( to_size( arr.size() ) )
|
|||
|
|
{}
|
|||
|
|
|
|||
|
|
#endif // span_HAVE( ARRAY )
|
|||
|
|
|
|||
|
|
#if span_HAVE( CONSTRAINED_SPAN_CONTAINER_CTOR )
|
|||
|
|
template< class Container
|
|||
|
|
span_REQUIRES_T((
|
|||
|
|
detail::is_compatible_container< Container, element_type >::value
|
|||
|
|
))
|
|||
|
|
>
|
|||
|
|
span_constexpr span( Container & cont )
|
|||
|
|
: data_( std17::data( cont ) )
|
|||
|
|
, size_( to_size( std17::size( cont ) ) )
|
|||
|
|
{}
|
|||
|
|
|
|||
|
|
template< class Container
|
|||
|
|
span_REQUIRES_T((
|
|||
|
|
std::is_const< element_type >::value
|
|||
|
|
&& detail::is_compatible_container< Container, element_type >::value
|
|||
|
|
))
|
|||
|
|
>
|
|||
|
|
span_constexpr span( Container const & cont )
|
|||
|
|
: data_( std17::data( cont ) )
|
|||
|
|
, size_( to_size( std17::size( cont ) ) )
|
|||
|
|
{}
|
|||
|
|
|
|||
|
|
#endif // span_HAVE( CONSTRAINED_SPAN_CONTAINER_CTOR )
|
|||
|
|
|
|||
|
|
#if span_FEATURE( WITH_CONTAINER )
|
|||
|
|
|
|||
|
|
template< class Container >
|
|||
|
|
span_constexpr span( with_container_t, Container & cont )
|
|||
|
|
: data_( cont.size() == 0 ? span_nullptr : span_ADDRESSOF( cont[0] ) )
|
|||
|
|
, size_( to_size( cont.size() ) )
|
|||
|
|
{}
|
|||
|
|
|
|||
|
|
template< class Container >
|
|||
|
|
span_constexpr span( with_container_t, Container const & cont )
|
|||
|
|
: data_( cont.size() == 0 ? span_nullptr : const_cast<pointer>( span_ADDRESSOF( cont[0] ) ) )
|
|||
|
|
, size_( to_size( cont.size() ) )
|
|||
|
|
{}
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE( IS_DEFAULT )
|
|||
|
|
span_constexpr span( span const & other ) span_noexcept = default;
|
|||
|
|
|
|||
|
|
~span() span_noexcept = default;
|
|||
|
|
|
|||
|
|
span_constexpr14 span & operator=( span const & other ) span_noexcept = default;
|
|||
|
|
#else
|
|||
|
|
span_constexpr span( span const & other ) span_noexcept
|
|||
|
|
: data_( other.data_ )
|
|||
|
|
, size_( other.size_ )
|
|||
|
|
{}
|
|||
|
|
|
|||
|
|
~span() span_noexcept
|
|||
|
|
{}
|
|||
|
|
|
|||
|
|
span_constexpr14 span & operator=( span const & other ) span_noexcept
|
|||
|
|
{
|
|||
|
|
data_ = other.data_;
|
|||
|
|
size_ = other.size_;
|
|||
|
|
|
|||
|
|
return *this;
|
|||
|
|
}
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
template< class OtherElementType, extent_type OtherExtent
|
|||
|
|
span_REQUIRES_T((
|
|||
|
|
(Extent == dynamic_extent || Extent == OtherExtent)
|
|||
|
|
&& std::is_convertible<OtherElementType(*)[], element_type(*)[]>::value
|
|||
|
|
))
|
|||
|
|
>
|
|||
|
|
span_constexpr_exp span( span<OtherElementType, OtherExtent> const & other ) span_noexcept
|
|||
|
|
: data_( reinterpret_cast<pointer>( other.data() ) )
|
|||
|
|
, size_( other.size() )
|
|||
|
|
{
|
|||
|
|
span_EXPECTS( OtherExtent == dynamic_extent || other.size() == to_size(OtherExtent) );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// 26.7.3.3 Subviews [span.sub]
|
|||
|
|
|
|||
|
|
template< extent_type Count >
|
|||
|
|
span_constexpr_exp span< element_type, Count >
|
|||
|
|
first() const
|
|||
|
|
{
|
|||
|
|
span_EXPECTS( detail::is_positive( Count ) && Count <= size() );
|
|||
|
|
|
|||
|
|
return span< element_type, Count >( data(), Count );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< extent_type Count >
|
|||
|
|
span_constexpr_exp span< element_type, Count >
|
|||
|
|
last() const
|
|||
|
|
{
|
|||
|
|
span_EXPECTS( detail::is_positive( Count ) && Count <= size() );
|
|||
|
|
|
|||
|
|
return span< element_type, Count >( data() + (size() - Count), Count );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#if span_HAVE( DEFAULT_FUNCTION_TEMPLATE_ARG )
|
|||
|
|
template< size_type Offset, extent_type Count = dynamic_extent >
|
|||
|
|
#else
|
|||
|
|
template< size_type Offset, extent_type Count /*= dynamic_extent*/ >
|
|||
|
|
#endif
|
|||
|
|
span_constexpr_exp span< element_type, Count >
|
|||
|
|
subspan() const
|
|||
|
|
{
|
|||
|
|
span_EXPECTS(
|
|||
|
|
( detail::is_positive( Offset ) && Offset <= size() ) &&
|
|||
|
|
( Count == dynamic_extent || (detail::is_positive( Count ) && Count + Offset <= size()) )
|
|||
|
|
);
|
|||
|
|
|
|||
|
|
return span< element_type, Count >(
|
|||
|
|
data() + Offset, Count != dynamic_extent ? Count : (Extent != dynamic_extent ? Extent - Offset : size() - Offset) );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr_exp span< element_type, dynamic_extent >
|
|||
|
|
first( size_type count ) const
|
|||
|
|
{
|
|||
|
|
span_EXPECTS( detail::is_positive( count ) && count <= size() );
|
|||
|
|
|
|||
|
|
return span< element_type, dynamic_extent >( data(), count );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr_exp span< element_type, dynamic_extent >
|
|||
|
|
last( size_type count ) const
|
|||
|
|
{
|
|||
|
|
span_EXPECTS( detail::is_positive( count ) && count <= size() );
|
|||
|
|
|
|||
|
|
return span< element_type, dynamic_extent >( data() + ( size() - count ), count );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr_exp span< element_type, dynamic_extent >
|
|||
|
|
subspan( size_type offset, size_type count = static_cast<size_type>(dynamic_extent) ) const
|
|||
|
|
{
|
|||
|
|
span_EXPECTS(
|
|||
|
|
( ( detail::is_positive( offset ) && offset <= size() ) ) &&
|
|||
|
|
( count == static_cast<size_type>(dynamic_extent) || ( detail::is_positive( count ) && offset + count <= size() ) )
|
|||
|
|
);
|
|||
|
|
|
|||
|
|
return span< element_type, dynamic_extent >(
|
|||
|
|
data() + offset, count == static_cast<size_type>(dynamic_extent) ? size() - offset : count );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// 26.7.3.4 Observers [span.obs]
|
|||
|
|
|
|||
|
|
span_constexpr size_type size() const span_noexcept
|
|||
|
|
{
|
|||
|
|
return size_;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr std::ptrdiff_t ssize() const span_noexcept
|
|||
|
|
{
|
|||
|
|
return static_cast<std::ptrdiff_t>( size_ );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr size_type size_bytes() const span_noexcept
|
|||
|
|
{
|
|||
|
|
return size() * to_size( sizeof( element_type ) );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_nodiscard span_constexpr bool empty() const span_noexcept
|
|||
|
|
{
|
|||
|
|
return size() == 0;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// 26.7.3.5 Element access [span.elem]
|
|||
|
|
|
|||
|
|
span_constexpr_exp reference operator[]( size_type idx ) const
|
|||
|
|
{
|
|||
|
|
span_EXPECTS( detail::is_positive( idx ) && idx < size() );
|
|||
|
|
|
|||
|
|
return *( data() + idx );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#if span_FEATURE( MEMBER_CALL_OPERATOR )
|
|||
|
|
span_deprecated("replace operator() with operator[]")
|
|||
|
|
|
|||
|
|
span_constexpr_exp reference operator()( size_type idx ) const
|
|||
|
|
{
|
|||
|
|
span_EXPECTS( detail::is_positive( idx ) && idx < size() );
|
|||
|
|
|
|||
|
|
return *( data() + idx );
|
|||
|
|
}
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_FEATURE( MEMBER_AT )
|
|||
|
|
span_constexpr14 reference at( size_type idx ) const
|
|||
|
|
{
|
|||
|
|
#if span_CONFIG( NO_EXCEPTIONS )
|
|||
|
|
return this->operator[]( idx );
|
|||
|
|
#else
|
|||
|
|
if ( !detail::is_positive( idx ) || size() <= idx )
|
|||
|
|
{
|
|||
|
|
detail::throw_out_of_range( idx, size() );
|
|||
|
|
}
|
|||
|
|
return *( data() + idx );
|
|||
|
|
#endif
|
|||
|
|
}
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
span_constexpr pointer data() const span_noexcept
|
|||
|
|
{
|
|||
|
|
return data_;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#if span_FEATURE( MEMBER_BACK_FRONT )
|
|||
|
|
|
|||
|
|
span_constexpr_exp reference front() const span_noexcept
|
|||
|
|
{
|
|||
|
|
span_EXPECTS( ! empty() );
|
|||
|
|
|
|||
|
|
return *data();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr_exp reference back() const span_noexcept
|
|||
|
|
{
|
|||
|
|
span_EXPECTS( ! empty() );
|
|||
|
|
|
|||
|
|
return *( data() + size() - 1 );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
// xx.x.x.x Modifiers [span.modifiers]
|
|||
|
|
|
|||
|
|
#if span_FEATURE( MEMBER_SWAP )
|
|||
|
|
|
|||
|
|
span_constexpr14 void swap( span & other ) span_noexcept
|
|||
|
|
{
|
|||
|
|
using std::swap;
|
|||
|
|
swap( data_, other.data_ );
|
|||
|
|
swap( size_, other.size_ );
|
|||
|
|
}
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
// 26.7.3.6 Iterator support [span.iterators]
|
|||
|
|
|
|||
|
|
span_constexpr iterator begin() const span_noexcept
|
|||
|
|
{
|
|||
|
|
#if span_CPP11_OR_GREATER
|
|||
|
|
return { data() };
|
|||
|
|
#else
|
|||
|
|
return iterator( data() );
|
|||
|
|
#endif
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr iterator end() const span_noexcept
|
|||
|
|
{
|
|||
|
|
#if span_CPP11_OR_GREATER
|
|||
|
|
return { data() + size() };
|
|||
|
|
#else
|
|||
|
|
return iterator( data() + size() );
|
|||
|
|
#endif
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr const_iterator cbegin() const span_noexcept
|
|||
|
|
{
|
|||
|
|
#if span_CPP11_OR_GREATER
|
|||
|
|
return { data() };
|
|||
|
|
#else
|
|||
|
|
return const_iterator( data() );
|
|||
|
|
#endif
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr const_iterator cend() const span_noexcept
|
|||
|
|
{
|
|||
|
|
#if span_CPP11_OR_GREATER
|
|||
|
|
return { data() + size() };
|
|||
|
|
#else
|
|||
|
|
return const_iterator( data() + size() );
|
|||
|
|
#endif
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr reverse_iterator rbegin() const span_noexcept
|
|||
|
|
{
|
|||
|
|
return reverse_iterator( end() );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr reverse_iterator rend() const span_noexcept
|
|||
|
|
{
|
|||
|
|
return reverse_iterator( begin() );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr const_reverse_iterator crbegin() const span_noexcept
|
|||
|
|
{
|
|||
|
|
return const_reverse_iterator ( cend() );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
span_constexpr const_reverse_iterator crend() const span_noexcept
|
|||
|
|
{
|
|||
|
|
return const_reverse_iterator( cbegin() );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
private:
|
|||
|
|
|
|||
|
|
// Note: C++20 has std::pointer_traits<Ptr>::to_address( it );
|
|||
|
|
|
|||
|
|
#if span_HAVE( ITERATOR_CTOR )
|
|||
|
|
static inline span_constexpr pointer to_address( std::nullptr_t ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return nullptr;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< typename U >
|
|||
|
|
static inline span_constexpr U * to_address( U * p ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return p;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< typename Ptr
|
|||
|
|
span_REQUIRES_T(( ! std::is_pointer<Ptr>::value ))
|
|||
|
|
>
|
|||
|
|
static inline span_constexpr pointer to_address( Ptr const & it ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return to_address( it.operator->() );
|
|||
|
|
}
|
|||
|
|
#endif // span_HAVE( ITERATOR_CTOR )
|
|||
|
|
|
|||
|
|
private:
|
|||
|
|
pointer data_;
|
|||
|
|
size_type size_;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
// class template argument deduction guides:
|
|||
|
|
|
|||
|
|
#if span_HAVE( DEDUCTION_GUIDES )
|
|||
|
|
|
|||
|
|
template< class T, size_t N >
|
|||
|
|
span( T (&)[N] ) -> span<T, static_cast<extent_t>(N)>;
|
|||
|
|
|
|||
|
|
template< class T, size_t N >
|
|||
|
|
span( std::array<T, N> & ) -> span<T, static_cast<extent_t>(N)>;
|
|||
|
|
|
|||
|
|
template< class T, size_t N >
|
|||
|
|
span( std::array<T, N> const & ) -> span<const T, static_cast<extent_t>(N)>;
|
|||
|
|
|
|||
|
|
#if span_HAVE( CONSTRAINED_SPAN_CONTAINER_CTOR )
|
|||
|
|
|
|||
|
|
template< class Container >
|
|||
|
|
span( Container& ) -> span<typename Container::value_type>;
|
|||
|
|
|
|||
|
|
template< class Container >
|
|||
|
|
span( Container const & ) -> span<const typename Container::value_type>;
|
|||
|
|
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
// iterator: constraints: It satisfies contiguous_iterator.
|
|||
|
|
|
|||
|
|
template< class It, class EndOrSize >
|
|||
|
|
span( It, EndOrSize ) -> span< typename std11::remove_reference< typename std20::iter_reference_t<It> >::type >;
|
|||
|
|
|
|||
|
|
#endif // span_HAVE( DEDUCTION_GUIDES )
|
|||
|
|
|
|||
|
|
// 26.7.3.7 Comparison operators [span.comparison]
|
|||
|
|
|
|||
|
|
#if span_FEATURE( COMPARISON )
|
|||
|
|
#if span_FEATURE( SAME )
|
|||
|
|
|
|||
|
|
template< class T1, extent_t E1, class T2, extent_t E2 >
|
|||
|
|
inline span_constexpr bool same( span<T1,E1> const & l, span<T2,E2> const & r ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return std11::is_same<T1, T2>::value
|
|||
|
|
&& l.size() == r.size()
|
|||
|
|
&& static_cast<void const*>( l.data() ) == r.data();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
template< class T1, extent_t E1, class T2, extent_t E2 >
|
|||
|
|
inline span_constexpr bool operator==( span<T1,E1> const & l, span<T2,E2> const & r )
|
|||
|
|
{
|
|||
|
|
return
|
|||
|
|
#if span_FEATURE( SAME )
|
|||
|
|
same( l, r ) ||
|
|||
|
|
#endif
|
|||
|
|
( l.size() == r.size() && std::equal( l.begin(), l.end(), r.begin() ) );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T1, extent_t E1, class T2, extent_t E2 >
|
|||
|
|
inline span_constexpr bool operator<( span<T1,E1> const & l, span<T2,E2> const & r )
|
|||
|
|
{
|
|||
|
|
return std::lexicographical_compare( l.begin(), l.end(), r.begin(), r.end() );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T1, extent_t E1, class T2, extent_t E2 >
|
|||
|
|
inline span_constexpr bool operator!=( span<T1,E1> const & l, span<T2,E2> const & r )
|
|||
|
|
{
|
|||
|
|
return !( l == r );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T1, extent_t E1, class T2, extent_t E2 >
|
|||
|
|
inline span_constexpr bool operator<=( span<T1,E1> const & l, span<T2,E2> const & r )
|
|||
|
|
{
|
|||
|
|
return !( r < l );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T1, extent_t E1, class T2, extent_t E2 >
|
|||
|
|
inline span_constexpr bool operator>( span<T1,E1> const & l, span<T2,E2> const & r )
|
|||
|
|
{
|
|||
|
|
return ( r < l );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T1, extent_t E1, class T2, extent_t E2 >
|
|||
|
|
inline span_constexpr bool operator>=( span<T1,E1> const & l, span<T2,E2> const & r )
|
|||
|
|
{
|
|||
|
|
return !( l < r );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#endif // span_FEATURE( COMPARISON )
|
|||
|
|
|
|||
|
|
// 26.7.2.6 views of object representation [span.objectrep]
|
|||
|
|
|
|||
|
|
#if span_HAVE( BYTE ) || span_HAVE( NONSTD_BYTE )
|
|||
|
|
|
|||
|
|
// Avoid MSVC 14.1 (1910), VS 2017: warning C4307: '*': integral constant overflow:
|
|||
|
|
|
|||
|
|
template< typename T, extent_t Extent >
|
|||
|
|
struct BytesExtent
|
|||
|
|
{
|
|||
|
|
#if span_CPP11_OR_GREATER
|
|||
|
|
enum ET : extent_t { value = span_sizeof(T) * Extent };
|
|||
|
|
#else
|
|||
|
|
enum ET { value = span_sizeof(T) * Extent };
|
|||
|
|
#endif
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
template< typename T >
|
|||
|
|
struct BytesExtent< T, dynamic_extent >
|
|||
|
|
{
|
|||
|
|
#if span_CPP11_OR_GREATER
|
|||
|
|
enum ET : extent_t { value = dynamic_extent };
|
|||
|
|
#else
|
|||
|
|
enum ET { value = dynamic_extent };
|
|||
|
|
#endif
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
template< class T, extent_t Extent >
|
|||
|
|
inline span_constexpr span< const std17::byte, BytesExtent<T, Extent>::value >
|
|||
|
|
as_bytes( span<T,Extent> spn ) span_noexcept
|
|||
|
|
{
|
|||
|
|
#if 0
|
|||
|
|
return { reinterpret_cast< std17::byte const * >( spn.data() ), spn.size_bytes() };
|
|||
|
|
#else
|
|||
|
|
return span< const std17::byte, BytesExtent<T, Extent>::value >(
|
|||
|
|
reinterpret_cast< std17::byte const * >( spn.data() ), spn.size_bytes() ); // NOLINT
|
|||
|
|
#endif
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T, extent_t Extent >
|
|||
|
|
inline span_constexpr span< std17::byte, BytesExtent<T, Extent>::value >
|
|||
|
|
as_writable_bytes( span<T,Extent> spn ) span_noexcept
|
|||
|
|
{
|
|||
|
|
#if 0
|
|||
|
|
return { reinterpret_cast< std17::byte * >( spn.data() ), spn.size_bytes() };
|
|||
|
|
#else
|
|||
|
|
return span< std17::byte, BytesExtent<T, Extent>::value >(
|
|||
|
|
reinterpret_cast< std17::byte * >( spn.data() ), spn.size_bytes() ); // NOLINT
|
|||
|
|
#endif
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#endif // span_HAVE( BYTE ) || span_HAVE( NONSTD_BYTE )
|
|||
|
|
|
|||
|
|
// extensions: non-member views:
|
|||
|
|
// this feature implies the presence of make_span()
|
|||
|
|
|
|||
|
|
#if span_FEATURE( NON_MEMBER_FIRST_LAST_SUB ) && span_CPP11_120
|
|||
|
|
|
|||
|
|
template< extent_t Count, class T >
|
|||
|
|
span_constexpr auto
|
|||
|
|
first( T & t ) -> decltype( make_span(t).template first<Count>() )
|
|||
|
|
{
|
|||
|
|
return make_span( t ).template first<Count>();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
span_constexpr auto
|
|||
|
|
first( T & t, size_t count ) -> decltype( make_span(t).first(count) )
|
|||
|
|
{
|
|||
|
|
return make_span( t ).first( count );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< extent_t Count, class T >
|
|||
|
|
span_constexpr auto
|
|||
|
|
last( T & t ) -> decltype( make_span(t).template last<Count>() )
|
|||
|
|
{
|
|||
|
|
return make_span(t).template last<Count>();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
span_constexpr auto
|
|||
|
|
last( T & t, extent_t count ) -> decltype( make_span(t).last(count) )
|
|||
|
|
{
|
|||
|
|
return make_span( t ).last( count );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< size_t Offset, extent_t Count = dynamic_extent, class T >
|
|||
|
|
span_constexpr auto
|
|||
|
|
subspan( T & t ) -> decltype( make_span(t).template subspan<Offset, Count>() )
|
|||
|
|
{
|
|||
|
|
return make_span( t ).template subspan<Offset, Count>();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
span_constexpr auto
|
|||
|
|
subspan( T & t, size_t offset, extent_t count = dynamic_extent ) -> decltype( make_span(t).subspan(offset, count) )
|
|||
|
|
{
|
|||
|
|
return make_span( t ).subspan( offset, count );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#endif // span_FEATURE( NON_MEMBER_FIRST_LAST_SUB )
|
|||
|
|
|
|||
|
|
// 27.8 Container and view access [iterator.container]
|
|||
|
|
|
|||
|
|
template< class T, extent_t Extent /*= dynamic_extent*/ >
|
|||
|
|
span_constexpr std::size_t size( span<T,Extent> const & spn )
|
|||
|
|
{
|
|||
|
|
return static_cast<std::size_t>( spn.size() );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T, extent_t Extent /*= dynamic_extent*/ >
|
|||
|
|
span_constexpr std::ptrdiff_t ssize( span<T,Extent> const & spn )
|
|||
|
|
{
|
|||
|
|
return static_cast<std::ptrdiff_t>( spn.size() );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
} // namespace span_lite
|
|||
|
|
} // namespace nonstd
|
|||
|
|
|
|||
|
|
// make available in nonstd:
|
|||
|
|
|
|||
|
|
namespace nonstd {
|
|||
|
|
|
|||
|
|
using span_lite::dynamic_extent;
|
|||
|
|
|
|||
|
|
using span_lite::span;
|
|||
|
|
|
|||
|
|
using span_lite::with_container;
|
|||
|
|
|
|||
|
|
#if span_FEATURE( COMPARISON )
|
|||
|
|
#if span_FEATURE( SAME )
|
|||
|
|
using span_lite::same;
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
using span_lite::operator==;
|
|||
|
|
using span_lite::operator!=;
|
|||
|
|
using span_lite::operator<;
|
|||
|
|
using span_lite::operator<=;
|
|||
|
|
using span_lite::operator>;
|
|||
|
|
using span_lite::operator>=;
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#if span_HAVE( BYTE )
|
|||
|
|
using span_lite::as_bytes;
|
|||
|
|
using span_lite::as_writable_bytes;
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
using span_lite::size;
|
|||
|
|
using span_lite::ssize;
|
|||
|
|
|
|||
|
|
} // namespace nonstd
|
|||
|
|
|
|||
|
|
#endif // span_USES_STD_SPAN
|
|||
|
|
|
|||
|
|
// make_span() [span-lite extension]:
|
|||
|
|
|
|||
|
|
#if span_FEATURE( MAKE_SPAN ) || span_FEATURE( NON_MEMBER_FIRST_LAST_SUB )
|
|||
|
|
|
|||
|
|
#if span_USES_STD_SPAN
|
|||
|
|
# define span_constexpr constexpr
|
|||
|
|
# define span_noexcept noexcept
|
|||
|
|
# define span_nullptr nullptr
|
|||
|
|
# ifndef span_CONFIG_EXTENT_TYPE
|
|||
|
|
# define span_CONFIG_EXTENT_TYPE std::size_t
|
|||
|
|
# endif
|
|||
|
|
using extent_t = span_CONFIG_EXTENT_TYPE;
|
|||
|
|
#endif // span_USES_STD_SPAN
|
|||
|
|
|
|||
|
|
namespace nonstd {
|
|||
|
|
namespace span_lite {
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
inline span_constexpr span<T>
|
|||
|
|
make_span( T * ptr, size_t count ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return span<T>( ptr, count );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
inline span_constexpr span<T>
|
|||
|
|
make_span( T * first, T * last ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return span<T>( first, last );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T, std::size_t N >
|
|||
|
|
inline span_constexpr span<T, static_cast<extent_t>(N)>
|
|||
|
|
make_span( T ( &arr )[ N ] ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return span<T, static_cast<extent_t>(N)>( &arr[ 0 ], N );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#if span_USES_STD_SPAN || span_HAVE( ARRAY )
|
|||
|
|
|
|||
|
|
template< class T, std::size_t N >
|
|||
|
|
inline span_constexpr span<T, static_cast<extent_t>(N)>
|
|||
|
|
make_span( std::array< T, N > & arr ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return span<T, static_cast<extent_t>(N)>( arr );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T, std::size_t N >
|
|||
|
|
inline span_constexpr span< const T, static_cast<extent_t>(N) >
|
|||
|
|
make_span( std::array< T, N > const & arr ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return span<const T, static_cast<extent_t>(N)>( arr );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#endif // span_HAVE( ARRAY )
|
|||
|
|
|
|||
|
|
#if span_USES_STD_SPAN
|
|||
|
|
|
|||
|
|
template< class Container, class EP = decltype( std::data(std::declval<Container&>())) >
|
|||
|
|
inline span_constexpr auto
|
|||
|
|
make_span( Container & cont ) span_noexcept -> span< typename std::remove_pointer<EP>::type >
|
|||
|
|
{
|
|||
|
|
return span< typename std::remove_pointer<EP>::type >( cont );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class Container, class EP = decltype( std::data(std::declval<Container&>())) >
|
|||
|
|
inline span_constexpr auto
|
|||
|
|
make_span( Container const & cont ) span_noexcept -> span< const typename std::remove_pointer<EP>::type >
|
|||
|
|
{
|
|||
|
|
return span< const typename std::remove_pointer<EP>::type >( cont );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#elif span_HAVE( CONSTRAINED_SPAN_CONTAINER_CTOR ) && span_HAVE( AUTO )
|
|||
|
|
|
|||
|
|
template< class Container, class EP = decltype( std17::data(std::declval<Container&>())) >
|
|||
|
|
inline span_constexpr auto
|
|||
|
|
make_span( Container & cont ) span_noexcept -> span< typename std::remove_pointer<EP>::type >
|
|||
|
|
{
|
|||
|
|
return span< typename std::remove_pointer<EP>::type >( cont );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class Container, class EP = decltype( std17::data(std::declval<Container&>())) >
|
|||
|
|
inline span_constexpr auto
|
|||
|
|
make_span( Container const & cont ) span_noexcept -> span< const typename std::remove_pointer<EP>::type >
|
|||
|
|
{
|
|||
|
|
return span< const typename std::remove_pointer<EP>::type >( cont );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#else
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
inline span_constexpr span<T>
|
|||
|
|
make_span( span<T> spn ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return spn;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T, class Allocator >
|
|||
|
|
inline span_constexpr span<T>
|
|||
|
|
make_span( std::vector<T, Allocator> & cont ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return span<T>( with_container, cont );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T, class Allocator >
|
|||
|
|
inline span_constexpr span<const T>
|
|||
|
|
make_span( std::vector<T, Allocator> const & cont ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return span<const T>( with_container, cont );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#endif // span_USES_STD_SPAN || ( ... )
|
|||
|
|
|
|||
|
|
#if ! span_USES_STD_SPAN && span_FEATURE( WITH_CONTAINER )
|
|||
|
|
|
|||
|
|
template< class Container >
|
|||
|
|
inline span_constexpr span<typename Container::value_type>
|
|||
|
|
make_span( with_container_t, Container & cont ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return span< typename Container::value_type >( with_container, cont );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class Container >
|
|||
|
|
inline span_constexpr span<const typename Container::value_type>
|
|||
|
|
make_span( with_container_t, Container const & cont ) span_noexcept
|
|||
|
|
{
|
|||
|
|
return span< const typename Container::value_type >( with_container, cont );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#endif // ! span_USES_STD_SPAN && span_FEATURE( WITH_CONTAINER )
|
|||
|
|
|
|||
|
|
|
|||
|
|
} // namespace span_lite
|
|||
|
|
} // namespace nonstd
|
|||
|
|
|
|||
|
|
// make available in nonstd:
|
|||
|
|
|
|||
|
|
namespace nonstd {
|
|||
|
|
using span_lite::make_span;
|
|||
|
|
} // namespace nonstd
|
|||
|
|
|
|||
|
|
#endif // #if span_FEATURE_TO_STD( MAKE_SPAN )
|
|||
|
|
|
|||
|
|
#if span_CPP11_OR_GREATER && span_FEATURE( BYTE_SPAN ) && ( span_HAVE( BYTE ) || span_HAVE( NONSTD_BYTE ) )
|
|||
|
|
|
|||
|
|
namespace nonstd {
|
|||
|
|
namespace span_lite {
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
inline span_constexpr auto
|
|||
|
|
byte_span( T & t ) span_noexcept -> span< std17::byte, span_sizeof(T) >
|
|||
|
|
{
|
|||
|
|
return span< std17::byte, span_sizeof(t) >( reinterpret_cast< std17::byte * >( &t ), span_sizeof(T) );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< class T >
|
|||
|
|
inline span_constexpr auto
|
|||
|
|
byte_span( T const & t ) span_noexcept -> span< const std17::byte, span_sizeof(T) >
|
|||
|
|
{
|
|||
|
|
return span< const std17::byte, span_sizeof(t) >( reinterpret_cast< std17::byte const * >( &t ), span_sizeof(T) );
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
} // namespace span_lite
|
|||
|
|
} // namespace nonstd
|
|||
|
|
|
|||
|
|
// make available in nonstd:
|
|||
|
|
|
|||
|
|
namespace nonstd {
|
|||
|
|
using span_lite::byte_span;
|
|||
|
|
} // namespace nonstd
|
|||
|
|
|
|||
|
|
#endif // span_FEATURE( BYTE_SPAN )
|
|||
|
|
|
|||
|
|
#if span_HAVE( STRUCT_BINDING )
|
|||
|
|
|
|||
|
|
#if span_CPP14_OR_GREATER
|
|||
|
|
# include <tuple>
|
|||
|
|
#elif span_CPP11_OR_GREATER
|
|||
|
|
# include <tuple>
|
|||
|
|
namespace std {
|
|||
|
|
template< std::size_t I, typename T >
|
|||
|
|
using tuple_element_t = typename tuple_element<I, T>::type;
|
|||
|
|
}
|
|||
|
|
#else
|
|||
|
|
namespace std {
|
|||
|
|
template< typename T >
|
|||
|
|
class tuple_size; /*undefined*/
|
|||
|
|
|
|||
|
|
template< std::size_t I, typename T >
|
|||
|
|
class tuple_element; /* undefined */
|
|||
|
|
}
|
|||
|
|
#endif // span_CPP14_OR_GREATER
|
|||
|
|
|
|||
|
|
namespace std {
|
|||
|
|
|
|||
|
|
// 26.7.X Tuple interface
|
|||
|
|
|
|||
|
|
// std::tuple_size<>:
|
|||
|
|
|
|||
|
|
template< typename ElementType, nonstd::span_lite::extent_t Extent >
|
|||
|
|
class tuple_size< nonstd::span<ElementType, Extent> > : public integral_constant<size_t, static_cast<size_t>(Extent)> {};
|
|||
|
|
|
|||
|
|
// std::tuple_size<>: Leave undefined for dynamic extent:
|
|||
|
|
|
|||
|
|
template< typename ElementType >
|
|||
|
|
class tuple_size< nonstd::span<ElementType, nonstd::dynamic_extent> >;
|
|||
|
|
|
|||
|
|
// std::tuple_element<>:
|
|||
|
|
|
|||
|
|
template< size_t I, typename ElementType, nonstd::span_lite::extent_t Extent >
|
|||
|
|
class tuple_element< I, nonstd::span<ElementType, Extent> >
|
|||
|
|
{
|
|||
|
|
public:
|
|||
|
|
#if span_HAVE( STATIC_ASSERT )
|
|||
|
|
static_assert( Extent != nonstd::dynamic_extent && I < Extent, "tuple_element<I,span>: dynamic extent or index out of range" );
|
|||
|
|
#endif
|
|||
|
|
using type = ElementType;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
// std::get<>(), 2 variants:
|
|||
|
|
|
|||
|
|
template< size_t I, typename ElementType, nonstd::span_lite::extent_t Extent >
|
|||
|
|
span_constexpr ElementType & get( nonstd::span<ElementType, Extent> & spn ) span_noexcept
|
|||
|
|
{
|
|||
|
|
#if span_HAVE( STATIC_ASSERT )
|
|||
|
|
static_assert( Extent != nonstd::dynamic_extent && I < Extent, "get<>(span): dynamic extent or index out of range" );
|
|||
|
|
#endif
|
|||
|
|
return spn[I];
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
template< size_t I, typename ElementType, nonstd::span_lite::extent_t Extent >
|
|||
|
|
span_constexpr ElementType const & get( nonstd::span<ElementType, Extent> const & spn ) span_noexcept
|
|||
|
|
{
|
|||
|
|
#if span_HAVE( STATIC_ASSERT )
|
|||
|
|
static_assert( Extent != nonstd::dynamic_extent && I < Extent, "get<>(span): dynamic extent or index out of range" );
|
|||
|
|
#endif
|
|||
|
|
return spn[I];
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
} // end namespace std
|
|||
|
|
|
|||
|
|
#endif // span_HAVE( STRUCT_BINDING )
|
|||
|
|
|
|||
|
|
#if ! span_USES_STD_SPAN
|
|||
|
|
span_RESTORE_WARNINGS()
|
|||
|
|
#endif // span_USES_STD_SPAN
|
|||
|
|
|
|||
|
|
#endif // NONSTD_SPAN_HPP_INCLUDED
|