88 lines
2.0 KiB
C++
88 lines
2.0 KiB
C++
// Copyright 2019 Peter Dimov
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//
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// Distributed under the Boost Software License, Version 1.0.
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// http://www.boost.org/LICENSE_1_0.txt
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#include <boost/endian/detail/order.hpp>
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#include <boost/core/lightweight_test.hpp>
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#include <boost/config.hpp>
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#include <boost/cstdint.hpp>
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#include <cstddef>
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#include <ostream>
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#include <iomanip>
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#if defined(_MSC_VER)
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# pragma warning(disable: 4127) // conditional expression is constant
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#endif
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class byte_span
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{
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private:
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unsigned char const * p_;
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std::size_t n_;
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public:
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byte_span( unsigned char const * p, std::size_t n ): p_( p ), n_( n )
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{
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}
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template<std::size_t N> explicit byte_span( unsigned char const (&a)[ N ] ): p_( a ), n_( N )
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{
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}
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bool operator==( byte_span const& r ) const
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{
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if( n_ != r.n_ ) return false;
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for( std::size_t i = 0; i < n_; ++i )
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{
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if( p_[ i ] != r.p_[ i ] ) return false;
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}
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return true;
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}
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friend std::ostream& operator<<( std::ostream& os, byte_span s )
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{
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if( s.n_ == 0 ) return os;
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os << std::hex << std::setfill( '0' ) << std::uppercase;
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os << std::setw( 2 ) << +s.p_[ 0 ];
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for( std::size_t i = 1; i < s.n_; ++i )
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{
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os << ':' << std::setw( 2 ) << +s.p_[ i ];
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}
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os << std::dec << std::setfill( ' ' ) << std::nouppercase;
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return os;
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}
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};
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int main()
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{
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boost::uint64_t v = static_cast<boost::uint64_t>( 0x0102030405060708ull );
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byte_span v2( reinterpret_cast<unsigned char const*>( &v ), sizeof(v) );
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if( boost::endian::order::native == boost::endian::order::little )
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{
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unsigned char w[] = { 8, 7, 6, 5, 4, 3, 2, 1 };
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BOOST_TEST_EQ( v2, byte_span( w ) );
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}
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else if( boost::endian::order::native == boost::endian::order::big )
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{
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unsigned char w[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
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BOOST_TEST_EQ( v2, byte_span( w ) );
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}
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else
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{
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BOOST_ERROR( "boost::endian::order::native is neither big nor little" );
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}
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return boost::report_errors();
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}
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