/External/boost/boost/utility/string_ref.hpp

/* 

   Copyright (c) Marshall Clow 2012-2012.



   Distributed under the Boost Software License, Version 1.0. (See accompanying

   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)



    For more information, see http://www.boost.org

    

    Based on the StringRef implementation in LLVM (http://llvm.org) and

    N3422 by Jeffrey Yasskin

        http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3442.html



*/



#ifndef BOOST_STRING_REF_HPP

#define BOOST_STRING_REF_HPP



#include <boost/config.hpp>

#include <boost/detail/workaround.hpp>



#include <stdexcept>

#include <algorithm>

#include <functional>

#include <string>



namespace boost {

    

    namespace detail {

    //  A helper functor because sometimes we don't have lambdas

        template <typename charT, typename traits>

        class string_ref_traits_eq {

        public:

            string_ref_traits_eq ( charT ch ) : ch_(ch) {}

            bool operator () ( charT val ) const { return traits::eq ( ch_, val ); }

            charT ch_;

            };

        }

    

    template<typename charT, typename traits> class basic_string_ref;

    typedef basic_string_ref<char,     std::char_traits<char> >        string_ref;

    typedef basic_string_ref<wchar_t,  std::char_traits<wchar_t> >    wstring_ref;



#ifndef BOOST_NO_CXX11_CHAR16_T

    typedef basic_string_ref<char16_t, std::char_traits<char16_t> > u16string_ref;

#endif



#ifndef BOOST_NO_CXX11_CHAR32_T

    typedef basic_string_ref<char32_t, std::char_traits<char32_t> > u32string_ref;

#endif

    

    template<typename charT, typename traits>

    class basic_string_ref {

    public:

        // types

        typedef charT value_type;

        typedef const charT* pointer;

        typedef const charT& reference;

        typedef const charT& const_reference;

        typedef pointer const_iterator; // impl-defined

        typedef const_iterator iterator;

        typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

        typedef const_reverse_iterator reverse_iterator;

        typedef std::size_t size_type;

        typedef ptrdiff_t difference_type;

        static BOOST_CONSTEXPR_OR_CONST size_type npos = size_type(-1);

        

        // construct/copy

        BOOST_CONSTEXPR basic_string_ref ()

            : ptr_(NULL), len_(0) {}



        BOOST_CONSTEXPR basic_string_ref (const basic_string_ref &rhs)

            : ptr_(rhs.ptr_), len_(rhs.len_) {}



        basic_string_ref& operator=(const basic_string_ref &rhs) {

            ptr_ = rhs.ptr_;

            len_ = rhs.len_;

            return *this;

            }

            

        basic_string_ref(const charT* str)

            : ptr_(str), len_(traits::length(str)) {}



        template<typename Allocator>

        basic_string_ref(const std::basic_string<charT, traits, Allocator>& str)

            : ptr_(str.data()), len_(str.length()) {}



        BOOST_CONSTEXPR basic_string_ref(const charT* str, size_type len)

            : ptr_(str), len_(len) {}



#ifndef BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS

        template<typename Allocator>

        explicit operator std::basic_string<charT, traits, Allocator>() const {

            return std::basic_string<charT, traits, Allocator> ( ptr_, len_ );

            }

#endif

        

        // iterators

        BOOST_CONSTEXPR const_iterator   begin() const { return ptr_; }

        BOOST_CONSTEXPR const_iterator  cbegin() const { return ptr_; }

        BOOST_CONSTEXPR const_iterator     end() const { return ptr_ + len_; }

        BOOST_CONSTEXPR const_iterator    cend() const { return ptr_ + len_; }

                const_reverse_iterator  rbegin() const { return const_reverse_iterator (end()); }

                const_reverse_iterator crbegin() const { return const_reverse_iterator (end()); }

                const_reverse_iterator    rend() const { return const_reverse_iterator (begin()); }

                const_reverse_iterator   crend() const { return const_reverse_iterator (begin()); }

        

        // capacity

        BOOST_CONSTEXPR size_type size()     const { return len_; }

        BOOST_CONSTEXPR size_type length()   const { return len_; }

        BOOST_CONSTEXPR size_type max_size() const { return len_; }

        BOOST_CONSTEXPR bool empty()         const { return len_ == 0; }

        

        // element access

        BOOST_CONSTEXPR const charT& operator[](size_type pos) const { return ptr_[pos]; }



        const charT& at(size_t pos) const {

            if ( pos >= len_ )

                throw std::out_of_range ( "boost::string_ref::at" );

            return ptr_[pos];

            }

            

        BOOST_CONSTEXPR const charT& front() const { return ptr_[0]; }

        BOOST_CONSTEXPR const charT& back()  const { return ptr_[len_-1]; }

        BOOST_CONSTEXPR const charT* data()  const { return ptr_; }

        

        // modifiers

        void clear() { len_ = 0; }

        void remove_prefix(size_type n) {

            if ( n > len_ )

                n = len_;

            ptr_ += n;

            len_ -= n;

            }

            

        void remove_suffix(size_type n) {

            if ( n > len_ )

                n = len_;

            len_ -= n;

            }

            

        

        // basic_string_ref string operations

        BOOST_CONSTEXPR

        basic_string_ref substr(size_type pos, size_type n=npos) const {

#if BOOST_WORKAROUND(BOOST_MSVC, <= 1600)

            // Looks like msvc 8 and 9 have a codegen bug when one branch of

            // a conditional operator is a throw expression. -EAN 2012/12/04

            if ( pos > size()) throw std::out_of_range ( "string_ref::substr" );

            if ( n == npos || pos + n > size()) n = size () - pos;

            return basic_string_ref ( data() + pos, n );

#else

            return pos > size() ? throw std::out_of_range ( "string_ref::substr" ) :

                basic_string_ref ( data() + pos, n == npos || pos + n > size() ? size() - pos : n );

#endif

            }

        

        int compare(basic_string_ref x) const {

            int cmp = traits::compare ( ptr_, x.ptr_, (std::min)(len_, x.len_));

            return cmp != 0 ? cmp : ( len_ == x.len_ ? 0 : len_ < x.len_ ? -1 : 1 );

            }

        

        bool starts_with(charT c) const { return !empty() && traits::eq ( c, front()); }

        bool starts_with(basic_string_ref x) const {

            return len_ >= x.len_ && traits::compare ( ptr_, x.ptr_, x.len_ ) == 0;

            }

        

        bool ends_with(charT c) const { return !empty() && traits::eq ( c, back()); }

        bool ends_with(basic_string_ref x) const {

            return len_ >= x.len_ && traits::compare ( ptr_ + len_ - x.len_, x.ptr_, x.len_ ) == 0;

            }



        size_type find(basic_string_ref s) const {

            const_iterator iter = std::search ( this->cbegin (), this->cend (), 

                                                s.cbegin (), s.cend (), traits::eq );

            return iter = this->cend () ? npos : std::distance ( this->cbegin (), iter );

            }

        

        size_type find(charT c) const {

            const_iterator iter = std::find_if ( this->cbegin (), this->cend (), 

                                    detail::string_ref_traits_eq<charT, traits> ( c ));

            return iter == this->cend () ? npos : std::distance ( this->cbegin (), iter );

            }

                        

        size_type rfind(basic_string_ref s) const {

            const_reverse_iterator iter = std::search ( this->crbegin (), this->crend (), 

                                                s.crbegin (), s.crend (), traits::eq );

            return iter == this->crend () ? npos : reverse_distance ( this->crbegin (), iter );

            }



        size_type rfind(charT c) const {

            const_reverse_iterator iter = std::find_if ( this->crbegin (), this->crend (), 

                                    detail::string_ref_traits_eq<charT, traits> ( c ));

            return iter == this->crend () ? npos : reverse_distance ( this->crbegin (), iter );

            }

        

        size_type find_first_of(charT c) const { return  find (c); }

        size_type find_last_of (charT c) const { return rfind (c); }

        

        size_type find_first_of(basic_string_ref s) const {

            const_iterator iter = std::find_first_of 

            	( this->cbegin (), this->cend (), s.cbegin (), s.cend (), traits::eq );

            return iter == this->cend () ? npos : std::distance ( this->cbegin (), iter );

            }

        

        size_type find_last_of(basic_string_ref s) const {

            const_reverse_iterator iter = std::find_first_of 

                ( this->crbegin (), this->crend (), s.cbegin (), s.cend (), traits::eq );

            return iter == this->crend () ? npos : reverse_distance ( this->crbegin (), iter);

            }

        

        size_type find_first_not_of(basic_string_ref s) const {

        	const_iterator iter = find_not_of ( this->cbegin (), this->cend (), s );

            return iter == this->cend () ? npos : std::distance ( this->cbegin (), iter );

            }

        

        size_type find_first_not_of(charT c) const {

            for ( const_iterator iter = this->cbegin (); iter != this->cend (); ++iter )

                if ( !traits::eq ( c, *iter ))

                    return std::distance ( this->cbegin (), iter );

            return npos;

            }

        

        size_type find_last_not_of(basic_string_ref s) const {

        	const_reverse_iterator iter = find_not_of ( this->crbegin (), this->crend (), s );

            return iter == this->crend () ? npos : reverse_distance ( this->crbegin (), iter );

            }

        

        size_type find_last_not_of(charT c) const {

            for ( const_reverse_iterator iter = this->crbegin (); iter != this->crend (); ++iter )

                if ( !traits::eq ( c, *iter ))

                    return reverse_distance ( this->crbegin (), iter );

            return npos;

            }



    private:

        template <typename r_iter>

        size_type reverse_distance ( r_iter first, r_iter last ) const {

            return len_ - 1 - std::distance ( first, last );

            }

        

        template <typename Iterator>

        Iterator find_not_of ( Iterator first, Iterator last, basic_string_ref s ) const {

			for ( ; first != last ; ++first )

				if ( 0 == traits::find ( s.ptr_, s.len_, *first ))

					return first;

			return last;

			}

		

       		

        

        const charT *ptr_;

        std::size_t len_;

        };

    

    // Comparison operators

    template<typename charT, typename traits>

    bool operator==(basic_string_ref<charT, traits> x, basic_string_ref<charT, traits> y) {

        if ( x.size () != y.size ()) return false;

        return x.compare(y) == 0;

        }

    

    template<typename charT, typename traits>

    bool operator!=(basic_string_ref<charT, traits> x, basic_string_ref<charT, traits> y) {

        if ( x.size () != y.size ()) return true;

        return x.compare(y) != 0;

        }



    template<typename charT, typename traits>

    bool operator<(basic_string_ref<charT, traits> x, basic_string_ref<charT, traits> y) {

        return x.compare(y) < 0;

        }



    template<typename charT, typename traits>

    bool operator>(basic_string_ref<charT, traits> x, basic_string_ref<charT, traits> y) {

        return x.compare(y) > 0;

        }



    template<typename charT, typename traits>

    bool operator<=(basic_string_ref<charT, traits> x, basic_string_ref<charT, traits> y) {

        return x.compare(y) <= 0;

        }



    template<typename charT, typename traits>

    bool operator>=(basic_string_ref<charT, traits> x, basic_string_ref<charT, traits> y) {

        return x.compare(y) >= 0;

        }



    

    // Inserter

    template<class charT, class traits>

    std::basic_ostream<charT, traits>&

    operator<<(std::basic_ostream<charT, traits>& os, const basic_string_ref<charT,traits>& str) {

#ifdef BOOST_NO_CXX11_RANGE_BASED_FOR

        for ( typename basic_string_ref<charT, traits>::const_iterator iter = str.begin (); iter != str.end (); ++iter )

            os << *iter;

#else

        for ( charT x : str )

            os << x;

#endif

        return os;

        }

    

#if 0

    // numeric conversions

    //

    //  These are short-term implementations.

    //  In a production environment, I would rather avoid the copying.

    //

    int stoi (string_ref str, size_t* idx=0, int base=10) {

        return std::stoi ( std::string(str), idx, base );

        }

    

    long stol (string_ref str, size_t* idx=0, int base=10) {

        return std::stol ( std::string(str), idx, base );

        }

        

    unsigned long stoul (string_ref str, size_t* idx=0, int base=10) {

        return std::stoul ( std::string(str), idx, base );

        }

        

    long long stoll (string_ref str, size_t* idx=0, int base=10) {

        return std::stoll ( std::string(str), idx, base );

        }

    

    unsigned long long stoull (string_ref str, size_t* idx=0, int base=10) {

        return std::stoull ( std::string(str), idx, base );

        }

    

    float stof (string_ref str, size_t* idx=0) {

        return std::stof ( std::string(str), idx );

        }

        

    double stod (string_ref str, size_t* idx=0) {

        return std::stod ( std::string(str), idx );

        }

        

    long double stold (string_ref str, size_t* idx=0)  {

        return std::stold ( std::string(str), idx );

        }

    

    int  stoi (wstring_ref str, size_t* idx=0, int base=10) {

        return std::stoi ( std::wstring(str), idx, base );

        }

        

    long stol (wstring_ref str, size_t* idx=0, int base=10) {

        return std::stol ( std::wstring(str), idx, base );

        }

        

    unsigned long stoul (wstring_ref str, size_t* idx=0, int base=10) {

        return std::stoul ( std::wstring(str), idx, base );

        }

        

    long long stoll (wstring_ref str, size_t* idx=0, int base=10) {

        return std::stoll ( std::wstring(str), idx, base );

        }

        

    unsigned long long stoull (wstring_ref str, size_t* idx=0, int base=10) {

        return std::stoull ( std::wstring(str), idx, base );

        }

    

    float  stof (wstring_ref str, size_t* idx=0) {

        return std::stof ( std::wstring(str), idx );

        }

        

    double stod (wstring_ref str, size_t* idx=0) {

        return std::stod ( std::wstring(str), idx );

        }

        

    long double stold (wstring_ref str, size_t* idx=0) {

        return std::stold ( std::wstring(str), idx );

        }

#endif



}



#if 0

namespace std {

    // Hashing

    template<> struct hash<boost::string_ref>;

    template<> struct hash<boost::u16string_ref>;

    template<> struct hash<boost::u32string_ref>;

    template<> struct hash<boost::wstring_ref>;

}

#endif



#endif