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Add boost/core/string_view.hpp
This commit is contained in:
Peter Dimov
567
include/boost/core/string_view.hpp
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567
include/boost/core/string_view.hpp
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@@ -0,0 +1,567 @@
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#ifndef BOOST_CORE_STRING_VIEW_HPP_INCLUDED
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#define BOOST_CORE_STRING_VIEW_HPP_INCLUDED
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// MS compatible compilers support #pragma once
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#if defined(_MSC_VER) && (_MSC_VER >= 1020)
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# pragma once
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#endif
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// boost::core::basic_string_view<Ch>
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//
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// Copyright 2021 Peter Dimov
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// Distributed under the Boost Software License, Version 1.0.
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// https://www.boost.org/LICENSE_1_0.txt
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#include <boost/assert.hpp>
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#include <boost/throw_exception.hpp>
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#include <boost/config.hpp>
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#include <string>
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#include <algorithm>
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#include <utility>
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#include <stdexcept>
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#include <cstddef>
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#include <cstring>
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#if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
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# include <string_view>
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#endif
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namespace boost
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{
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namespace core
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{
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template<class Ch> class basic_string_view
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{
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private:
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Ch const* p_;
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std::size_t n_;
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public:
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// types
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typedef std::char_traits<Ch> traits_type;
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typedef Ch value_type;
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typedef Ch* pointer;
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typedef Ch const* const_pointer;
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typedef Ch& reference;
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typedef Ch const& const_reference;
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typedef Ch const* const_iterator;
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typedef const_iterator iterator;
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typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
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typedef const_reverse_iterator reverse_iterator;
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typedef std::size_t size_type;
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typedef std::ptrdiff_t difference_type;
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// npos
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BOOST_STATIC_CONSTEXPR size_type npos = static_cast<size_type>( -1 );
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public:
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// construction and assignment
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BOOST_CONSTEXPR basic_string_view() BOOST_NOEXCEPT: p_(), n_()
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{
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}
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BOOST_CONSTEXPR basic_string_view( Ch const* str ) BOOST_NOEXCEPT: p_( str ), n_( traits_type::length( str ) )
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{
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}
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BOOST_CONSTEXPR basic_string_view( Ch const* str, size_type len ) BOOST_NOEXCEPT: p_( str ), n_( len )
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{
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}
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BOOST_CXX14_CONSTEXPR basic_string_view( Ch const* begin, Ch const* end ) BOOST_NOEXCEPT: p_( begin ), n_( end - begin )
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{
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BOOST_ASSERT( end - begin >= 0 );
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}
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template<class A> basic_string_view( std::basic_string<Ch, std::char_traits<Ch>, A> const& str ) BOOST_NOEXCEPT: p_( str.data() ), n_( str.size() )
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{
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}
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#if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
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basic_string_view( std::basic_string_view<Ch, std::char_traits<Ch> > const& str ) BOOST_NOEXCEPT: p_( str.data() ), n_( str.size() )
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{
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}
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#endif
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// BOOST_CONSTEXPR basic_string_view& operator=( basic_string_view const& ) BOOST_NOEXCEPT & = default;
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// iterator support
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BOOST_CONSTEXPR const_iterator begin() const BOOST_NOEXCEPT
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{
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return p_;
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}
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BOOST_CONSTEXPR const_iterator end() const BOOST_NOEXCEPT
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{
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return p_ + n_;
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}
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BOOST_CONSTEXPR const_iterator cbegin() const BOOST_NOEXCEPT
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{
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return p_;
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}
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BOOST_CONSTEXPR const_iterator cend() const BOOST_NOEXCEPT
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{
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return p_ + n_;
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}
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BOOST_CONSTEXPR const_reverse_iterator rbegin() const BOOST_NOEXCEPT
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{
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return const_reverse_iterator( begin() );
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}
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BOOST_CONSTEXPR const_reverse_iterator rend() const BOOST_NOEXCEPT
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{
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return const_reverse_iterator( end() );
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}
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BOOST_CONSTEXPR const_reverse_iterator crbegin() const BOOST_NOEXCEPT
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{
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return const_reverse_iterator( begin() );
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}
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BOOST_CONSTEXPR const_reverse_iterator crend() const BOOST_NOEXCEPT
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{
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return const_reverse_iterator( end() );
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}
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// capacity
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BOOST_CONSTEXPR size_type size() const BOOST_NOEXCEPT
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{
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return n_;
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}
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BOOST_CONSTEXPR size_type length() const BOOST_NOEXCEPT
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{
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return n_;
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}
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BOOST_CONSTEXPR size_type max_size() const BOOST_NOEXCEPT
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{
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return npos / sizeof( Ch );
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}
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BOOST_CONSTEXPR bool empty() const BOOST_NOEXCEPT
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{
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return n_ == 0;
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}
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// element access
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BOOST_CONSTEXPR const_reference operator[]( size_type pos ) const BOOST_NOEXCEPT
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{
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BOOST_ASSERT( pos < size() );
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return p_[ pos ];
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}
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BOOST_CONSTEXPR const_reference at( size_type pos ) const
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{
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if( pos >= size() )
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{
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boost::throw_exception( std::out_of_range( "basic_string_view::at" ), BOOST_CURRENT_LOCATION );
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}
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return p_[ pos ];
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}
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BOOST_CONSTEXPR const_reference front() const BOOST_NOEXCEPT
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{
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BOOST_ASSERT( !empty() );
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return p_[ 0 ];
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}
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BOOST_CONSTEXPR const_reference back() const BOOST_NOEXCEPT
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{
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BOOST_ASSERT( !empty() );
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return p_[ n_ - 1 ];
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}
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BOOST_CONSTEXPR const_pointer data() const BOOST_NOEXCEPT
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{
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return p_;
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}
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// modifiers
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BOOST_CXX14_CONSTEXPR void remove_prefix( size_type n ) BOOST_NOEXCEPT
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{
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BOOST_ASSERT( n <= size() );
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p_ += n;
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n_ -= n;
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}
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BOOST_CXX14_CONSTEXPR void remove_suffix( size_type n ) BOOST_NOEXCEPT
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{
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BOOST_ASSERT( n <= size() );
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n_ -= n;
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}
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BOOST_CXX14_CONSTEXPR void swap( basic_string_view& s ) BOOST_NOEXCEPT
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{
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std::swap( p_, s.p_ );
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std::swap( n_, s.n_ );
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}
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// string operations
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BOOST_CONSTEXPR size_type copy( Ch* s, size_type n, size_type pos = 0 ) const
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{
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if( pos > size() )
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{
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boost::throw_exception( std::out_of_range( "basic_string_view::copy" ), BOOST_CURRENT_LOCATION );
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}
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std::size_t rlen = std::min( n, size() - pos );
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traits_type::copy( s, data() + pos, rlen );
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return rlen;
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}
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BOOST_CONSTEXPR basic_string_view substr( size_type pos = 0, size_type n = npos ) const
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{
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if( pos > size() )
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{
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boost::throw_exception( std::out_of_range( "basic_string_view::substr" ), BOOST_CURRENT_LOCATION );
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}
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std::size_t rlen = std::min( n, size() - pos );
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return basic_string_view( data() + pos, rlen );
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}
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// compare
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BOOST_CONSTEXPR int compare( basic_string_view str ) const BOOST_NOEXCEPT
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{
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std::size_t rlen = std::min( size(), str.size() );
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int cmp = traits_type::compare( data(), str.data(), rlen );
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if( cmp != 0 ) return cmp;
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if( size() == str.size() ) return 0;
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return size() < str.size()? -1: +1;
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}
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BOOST_CONSTEXPR int compare( size_type pos1, size_type n1, basic_string_view str ) const
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{
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return substr( pos1, n1 ).compare( str );
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}
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BOOST_CONSTEXPR int compare( size_type pos1, size_type n1, basic_string_view str, size_type pos2, size_type n2 ) const
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{
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return substr( pos1, n1 ).compare( str.substr( pos2, n2 ) );
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}
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BOOST_CONSTEXPR int compare( Ch const* s ) const BOOST_NOEXCEPT
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{
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return compare( basic_string_view( s ) );
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}
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BOOST_CONSTEXPR int compare( size_type pos1, size_type n1, Ch const* s ) const
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{
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return substr( pos1, n1 ).compare( basic_string_view( s ) );
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}
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BOOST_CONSTEXPR int compare( size_type pos1, size_type n1, Ch const* s, size_type n2 ) const
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{
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return substr( pos1, n1 ).compare( basic_string_view( s, n2 ) );
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}
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// starts_with
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BOOST_CONSTEXPR bool starts_with( basic_string_view x ) const BOOST_NOEXCEPT
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{
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return substr( 0, x.size() ) == x;
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}
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BOOST_CONSTEXPR bool starts_with( Ch x ) const BOOST_NOEXCEPT
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{
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return !empty() && front() == x;
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}
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BOOST_CONSTEXPR bool starts_with( Ch const* x ) const
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{
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return starts_with( basic_string_view( x ) );
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}
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// ends_with
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BOOST_CONSTEXPR bool ends_with( basic_string_view x ) const BOOST_NOEXCEPT
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{
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return size() >= x.size() && compare( size() - x.size(), npos, x ) == 0;
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}
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BOOST_CONSTEXPR bool ends_with( Ch x ) const BOOST_NOEXCEPT
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{
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return !empty() && back() == x;
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}
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BOOST_CONSTEXPR bool ends_with( Ch const* x ) const
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{
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return ends_with( basic_string_view( x ) );
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}
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// find
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BOOST_CONSTEXPR size_type find( basic_string_view str, size_type pos = 0 ) const BOOST_NOEXCEPT
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{
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return find( str.data(), pos, str.size() );
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}
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BOOST_CONSTEXPR size_type find( Ch c, size_type pos = 0 ) const BOOST_NOEXCEPT
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{
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if( pos >= size() ) return npos;
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Ch const* r = traits_type::find( data() + pos, size() - pos, c );
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return r? r - data(): npos;
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}
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BOOST_CONSTEXPR size_type find( Ch const* s, size_type pos, size_type n ) const BOOST_NOEXCEPT
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{
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if( pos + n > size() ) return npos;
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if( n == 0 ) return pos;
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Ch const* p = data() + pos;
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Ch const* last = data() + size();
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for( ;; )
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{
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p = traits_type::find( p, last - p, s[0] );
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if( p == 0 ) break;
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if( last - p < n ) break;
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if( traits_type::compare( p, s, n ) == 0 ) return p - data();
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++p;
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}
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return npos;
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}
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BOOST_CONSTEXPR size_type find( Ch const* s, size_type pos = 0 ) const BOOST_NOEXCEPT
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{
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return find( s, pos, traits_type::length( s ) );
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}
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// rfind
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BOOST_CONSTEXPR size_type rfind( basic_string_view str, size_type pos = npos ) const BOOST_NOEXCEPT
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{
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return rfind( str.data(), pos, str.size() );
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}
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BOOST_CONSTEXPR size_type rfind( Ch c, size_type pos = npos ) const BOOST_NOEXCEPT
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{
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if( pos > size() )
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{
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pos = size();
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}
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const_reverse_iterator r = std::find( rbegin() + pos, rend(), c );
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return r == rend()? npos: size() - 1 - ( r - rbegin() );
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}
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BOOST_CONSTEXPR size_type rfind( Ch const* s, size_type pos, size_type n ) const BOOST_NOEXCEPT
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{
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if( n > size() ) return npos;
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if( pos > size() - n )
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{
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pos = size() - n;
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}
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if( n == 0 ) return pos;
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for( ;; )
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{
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size_type xpos = rfind( s[0], pos );
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if( xpos == npos ) return npos;
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if( traits_type::compare( data() + xpos, s, n ) == 0 ) return xpos;
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if( xpos == 0 ) return npos;
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pos = xpos - 1;
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}
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}
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BOOST_CONSTEXPR size_type rfind( Ch const* s, size_type pos = npos ) const BOOST_NOEXCEPT
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{
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return rfind( s, pos, traits_type::length( s ) );
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}
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// find_first_of
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BOOST_CONSTEXPR size_type find_first_of( basic_string_view str, size_type pos = 0 ) const BOOST_NOEXCEPT
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{
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for( std::size_t i = pos; i < n_; ++i )
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{
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if( str.contains( p_[ i ] ) ) return i;
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}
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return npos;
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}
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BOOST_CONSTEXPR size_type find_first_of( Ch c, size_type pos = 0 ) const BOOST_NOEXCEPT
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{
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return find( c, pos );
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}
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BOOST_CONSTEXPR size_type find_first_of( Ch const* s, size_type pos, size_type n ) const BOOST_NOEXCEPT
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{
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return find_first_of( basic_string_view( s, n ), pos );
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}
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BOOST_CONSTEXPR size_type find_first_of( Ch const* s, size_type pos = 0 ) const BOOST_NOEXCEPT
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{
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return find_first_of( basic_string_view( s ), pos );
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}
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// find_last_of
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BOOST_CONSTEXPR size_type find_last_of( basic_string_view str, size_type pos = npos ) const BOOST_NOEXCEPT
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{
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if( pos > size() )
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||||
{
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pos = size();
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}
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for( std::size_t i = pos; i > 0; --i )
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{
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if( str.contains( p_[ i - 1 ] ) ) return i - 1;
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}
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return npos;
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||||
}
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BOOST_CONSTEXPR size_type find_last_of( Ch c, size_type pos = npos ) const BOOST_NOEXCEPT
|
||||
{
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return rfind( c, pos );
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||||
}
|
||||
|
||||
BOOST_CONSTEXPR size_type find_last_of( Ch const* s, size_type pos, size_type n ) const BOOST_NOEXCEPT
|
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{
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return find_last_of( basic_string_view( s, n ), pos );
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||||
}
|
||||
|
||||
BOOST_CONSTEXPR size_type find_last_of( Ch const* s, size_type pos = npos ) const BOOST_NOEXCEPT
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||||
{
|
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return find_last_of( basic_string_view( s ), pos );
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||||
}
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||||
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||||
// find_first_not_of
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||||
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||||
BOOST_CONSTEXPR size_type find_first_not_of( basic_string_view str, size_type pos = 0 ) const BOOST_NOEXCEPT
|
||||
{
|
||||
for( std::size_t i = pos; i < n_; ++i )
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||||
{
|
||||
if( !str.contains( p_[ i ] ) ) return i;
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}
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||||
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||||
return npos;
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||||
}
|
||||
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||||
BOOST_CONSTEXPR size_type find_first_not_of( Ch c, size_type pos = 0 ) const BOOST_NOEXCEPT
|
||||
{
|
||||
for( std::size_t i = pos; i < n_; ++i )
|
||||
{
|
||||
if( p_[ i ] != c ) return i;
|
||||
}
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||||
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||||
return npos;
|
||||
}
|
||||
|
||||
BOOST_CONSTEXPR size_type find_first_not_of( Ch const* s, size_type pos, size_type n ) const BOOST_NOEXCEPT
|
||||
{
|
||||
return find_first_not_of( basic_string_view( s, n ), pos );
|
||||
}
|
||||
|
||||
BOOST_CONSTEXPR size_type find_first_not_of( Ch const* s, size_type pos = 0 ) const BOOST_NOEXCEPT
|
||||
{
|
||||
return find_first_not_of( basic_string_view( s ), pos );
|
||||
}
|
||||
|
||||
// find_last_not_of
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||||
|
||||
BOOST_CONSTEXPR size_type find_last_not_of( basic_string_view str, size_type pos = npos ) const BOOST_NOEXCEPT
|
||||
{
|
||||
if( pos > size() )
|
||||
{
|
||||
pos = size();
|
||||
}
|
||||
|
||||
for( std::size_t i = pos; i > 0; --i )
|
||||
{
|
||||
if( !str.contains( p_[ i - 1 ] ) ) return i - 1;
|
||||
}
|
||||
|
||||
return npos;
|
||||
}
|
||||
|
||||
BOOST_CONSTEXPR size_type find_last_not_of( Ch c, size_type pos = npos ) const BOOST_NOEXCEPT
|
||||
{
|
||||
if( pos > size() )
|
||||
{
|
||||
pos = size();
|
||||
}
|
||||
|
||||
for( std::size_t i = pos; i > 0; --i )
|
||||
{
|
||||
if( p_[ i - 1 ] != c ) return i - 1;
|
||||
}
|
||||
|
||||
return npos;
|
||||
}
|
||||
|
||||
BOOST_CONSTEXPR size_type find_last_not_of( Ch const* s, size_type pos, size_type n ) const BOOST_NOEXCEPT
|
||||
{
|
||||
return find_last_not_of( basic_string_view( s, n ), pos );
|
||||
}
|
||||
|
||||
BOOST_CONSTEXPR size_type find_last_not_of( Ch const* s, size_type pos = npos ) const BOOST_NOEXCEPT
|
||||
{
|
||||
return find_last_not_of( basic_string_view( s ), pos );
|
||||
}
|
||||
|
||||
// contains
|
||||
|
||||
BOOST_CONSTEXPR bool contains( basic_string_view sv ) const BOOST_NOEXCEPT
|
||||
{
|
||||
return find( sv ) != npos;
|
||||
}
|
||||
|
||||
BOOST_CONSTEXPR bool contains( Ch c ) const BOOST_NOEXCEPT
|
||||
{
|
||||
return traits_type::find( data(), size(), c ) == 0;
|
||||
}
|
||||
|
||||
BOOST_CONSTEXPR bool contains( Ch const* s ) const BOOST_NOEXCEPT
|
||||
{
|
||||
return find( s ) != npos;
|
||||
}
|
||||
};
|
||||
|
||||
#if defined(BOOST_NO_CXX17_INLINE_VARIABLES)
|
||||
template<class Ch> std::size_t const basic_string_view<Ch>::npos;
|
||||
#endif
|
||||
|
||||
Reference in New Issue
Block a user