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