third_party/LLVM/include/llvm/ADT/StringRef.h - SwiftShader - Git at Google

 //===--- StringRef.h - Constant String Reference Wrapper --------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//

 #ifndef LLVM_ADT_STRINGREF_H
 #define LLVM_ADT_STRINGREF_H

 #include <cassert>
 #include <cstring>
 #include <utility>
 #include <string>

 namespace llvm {
   template<typename T>
   class SmallVectorImpl;
   class APInt;

   /// StringRef - Represent a constant reference to a string, i.e. a character
   /// array and a length, which need not be null terminated.
   ///
   /// This class does not own the string data, it is expected to be used in
   /// situations where the character data resides in some other buffer, whose
   /// lifetime extends past that of the StringRef. For this reason, it is not in
   /// general safe to store a StringRef.
   class StringRef {
   public:
     typedef const char *iterator;
     typedef const char *const_iterator;
     static const size_t npos = ~size_t(0);
     typedef size_t size_type;

   private:
     /// The start of the string, in an external buffer.
     const char *Data;

     /// The length of the string.
     size_t Length;

     // Workaround PR5482: nearly all gcc 4.x miscompile StringRef and std::min()
     // Changing the arg of min to be an integer, instead of a reference to an
     // integer works around this bug.
     static size_t min(size_t a, size_t b) { return a < b ? a : b; }
     static size_t max(size_t a, size_t b) { return a > b ? a : b; }

     // Workaround memcmp issue with null pointers (undefined behavior)
     // by providing a specialized version
     static int compareMemory(const char *Lhs, const char *Rhs, size_t Length) {
       if (Length == 0) { return 0; }
       return ::memcmp(Lhs,Rhs,Length);
     }

   public:
     /// @name Constructors
     /// @{

     /// Construct an empty string ref.
     /*implicit*/ StringRef() : Data(0), Length(0) {}

     /// Construct a string ref from a cstring.
     /*implicit*/ StringRef(const char *Str)
       : Data(Str) {
         assert(Str && "StringRef cannot be built from a NULL argument");
         Length = ::strlen(Str); // invoking strlen(NULL) is undefined behavior
       }

     /// Construct a string ref from a pointer and length.
     /*implicit*/ StringRef(const char *data, size_t length)
       : Data(data), Length(length) {
         assert((data || length == 0) &&
         "StringRef cannot be built from a NULL argument with non-null length");
       }

     /// Construct a string ref from an std::string.
     /*implicit*/ StringRef(const std::string &Str)
       : Data(Str.data()), Length(Str.length()) {}

     /// @}
     /// @name Iterators
     /// @{

     iterator begin() const { return Data; }

     iterator end() const { return Data + Length; }

     /// @}
     /// @name String Operations
     /// @{

     /// data - Get a pointer to the start of the string (which may not be null
     /// terminated).
     const char *data() const { return Data; }

     /// empty - Check if the string is empty.
     bool empty() const { return Length == 0; }

     /// size - Get the string size.
     size_t size() const { return Length; }

     /// front - Get the first character in the string.
     char front() const {
       assert(!empty());
       return Data[0];
     }

     /// back - Get the last character in the string.
     char back() const {
       assert(!empty());
       return Data[Length-1];
     }

     /// equals - Check for string equality, this is more efficient than
     /// compare() when the relative ordering of inequal strings isn't needed.
     bool equals(StringRef RHS) const {
       return (Length == RHS.Length &&
               compareMemory(Data, RHS.Data, RHS.Length) == 0);
     }

     /// equals_lower - Check for string equality, ignoring case.
     bool equals_lower(StringRef RHS) const {
       return Length == RHS.Length && compare_lower(RHS) == 0;
     }

     /// compare - Compare two strings; the result is -1, 0, or 1 if this string
     /// is lexicographically less than, equal to, or greater than the \arg RHS.
     int compare(StringRef RHS) const {
       // Check the prefix for a mismatch.
       if (int Res = compareMemory(Data, RHS.Data, min(Length, RHS.Length)))
         return Res < 0 ? -1 : 1;

       // Otherwise the prefixes match, so we only need to check the lengths.
       if (Length == RHS.Length)
         return 0;
       return Length < RHS.Length ? -1 : 1;
     }

     /// compare_lower - Compare two strings, ignoring case.
     int compare_lower(StringRef RHS) const;

     /// compare_numeric - Compare two strings, treating sequences of digits as
     /// numbers.
     int compare_numeric(StringRef RHS) const;

     /// \brief Determine the edit distance between this string and another
     /// string.
     ///
     /// \param Other the string to compare this string against.
     ///
     /// \param AllowReplacements whether to allow character
     /// replacements (change one character into another) as a single
     /// operation, rather than as two operations (an insertion and a
     /// removal).
     ///
     /// \param MaxEditDistance If non-zero, the maximum edit distance that
     /// this routine is allowed to compute. If the edit distance will exceed
     /// that maximum, returns \c MaxEditDistance+1.
     ///
     /// \returns the minimum number of character insertions, removals,
     /// or (if \p AllowReplacements is \c true) replacements needed to
     /// transform one of the given strings into the other. If zero,
     /// the strings are identical.
     unsigned edit_distance(StringRef Other, bool AllowReplacements = true,
                            unsigned MaxEditDistance = 0);

     /// str - Get the contents as an std::string.
     std::string str() const {
       if (Data == 0) return std::string();
       return std::string(Data, Length);
     }

     /// @}
     /// @name Operator Overloads
     /// @{

     char operator[](size_t Index) const {
       assert(Index < Length && "Invalid index!");
       return Data[Index];
     }

     /// @}
     /// @name Type Conversions
     /// @{

     operator std::string() const {
       return str();
     }

     /// @}
     /// @name String Predicates
     /// @{

     /// startswith - Check if this string starts with the given \arg Prefix.
     bool startswith(StringRef Prefix) const {
       return Length >= Prefix.Length &&
              compareMemory(Data, Prefix.Data, Prefix.Length) == 0;
     }

     /// endswith - Check if this string ends with the given \arg Suffix.
     bool endswith(StringRef Suffix) const {
       return Length >= Suffix.Length &&
         compareMemory(end() - Suffix.Length, Suffix.Data, Suffix.Length) == 0;
     }

     /// @}
     /// @name String Searching
     /// @{

     /// find - Search for the first character \arg C in the string.
     ///
     /// \return - The index of the first occurrence of \arg C, or npos if not
     /// found.
     size_t find(char C, size_t From = 0) const {
       for (size_t i = min(From, Length), e = Length; i != e; ++i)
         if (Data[i] == C)
           return i;
       return npos;
     }

     /// find - Search for the first string \arg Str in the string.
     ///
     /// \return - The index of the first occurrence of \arg Str, or npos if not
     /// found.
     size_t find(StringRef Str, size_t From = 0) const;

     /// rfind - Search for the last character \arg C in the string.
     ///
     /// \return - The index of the last occurrence of \arg C, or npos if not
     /// found.
     size_t rfind(char C, size_t From = npos) const {
       From = min(From, Length);
       size_t i = From;
       while (i != 0) {
         --i;
         if (Data[i] == C)
           return i;
       }
       return npos;
     }

     /// rfind - Search for the last string \arg Str in the string.
     ///
     /// \return - The index of the last occurrence of \arg Str, or npos if not
     /// found.
     size_t rfind(StringRef Str) const;

     /// find_first_of - Find the first character in the string that is \arg C,
     /// or npos if not found. Same as find.
     size_type find_first_of(char C, size_t From = 0) const {
       return find(C, From);
     }

     /// find_first_of - Find the first character in the string that is in \arg
     /// Chars, or npos if not found.
     ///
     /// Note: O(size() + Chars.size())
     size_type find_first_of(StringRef Chars, size_t From = 0) const;

     /// find_first_not_of - Find the first character in the string that is not
     /// \arg C or npos if not found.
     size_type find_first_not_of(char C, size_t From = 0) const;

     /// find_first_not_of - Find the first character in the string that is not
     /// in the string \arg Chars, or npos if not found.
     ///
     /// Note: O(size() + Chars.size())
     size_type find_first_not_of(StringRef Chars, size_t From = 0) const;

     /// find_last_of - Find the last character in the string that is \arg C, or
     /// npos if not found.
     size_type find_last_of(char C, size_t From = npos) const {
       return rfind(C, From);
     }

     /// find_last_of - Find the last character in the string that is in \arg C,
     /// or npos if not found.
     ///
     /// Note: O(size() + Chars.size())
     size_type find_last_of(StringRef Chars, size_t From = npos) const;

     /// @}
     /// @name Helpful Algorithms
     /// @{

     /// count - Return the number of occurrences of \arg C in the string.
     size_t count(char C) const {
       size_t Count = 0;
       for (size_t i = 0, e = Length; i != e; ++i)
         if (Data[i] == C)
           ++Count;
       return Count;
     }

     /// count - Return the number of non-overlapped occurrences of \arg Str in
     /// the string.
     size_t count(StringRef Str) const;

     /// getAsInteger - Parse the current string as an integer of the specified
     /// radix.  If Radix is specified as zero, this does radix autosensing using
     /// extended C rules: 0 is octal, 0x is hex, 0b is binary.
     ///
     /// If the string is invalid or if only a subset of the string is valid,
     /// this returns true to signify the error.  The string is considered
     /// erroneous if empty.
     ///
     bool getAsInteger(unsigned Radix, long long &Result) const;
     bool getAsInteger(unsigned Radix, unsigned long long &Result) const;
     bool getAsInteger(unsigned Radix, int &Result) const;
     bool getAsInteger(unsigned Radix, unsigned &Result) const;

     // TODO: Provide overloads for int/unsigned that check for overflow.

     /// getAsInteger - Parse the current string as an integer of the
     /// specified radix, or of an autosensed radix if the radix given
     /// is 0.  The current value in Result is discarded, and the
     /// storage is changed to be wide enough to store the parsed
     /// integer.
     ///
     /// Returns true if the string does not solely consist of a valid
     /// non-empty number in the appropriate base.
     ///
     /// APInt::fromString is superficially similar but assumes the
     /// string is well-formed in the given radix.
     bool getAsInteger(unsigned Radix, APInt &Result) const;

     /// @}
     /// @name Substring Operations
     /// @{

     /// substr - Return a reference to the substring from [Start, Start + N).
     ///
     /// \param Start - The index of the starting character in the substring; if
     /// the index is npos or greater than the length of the string then the
     /// empty substring will be returned.
     ///
     /// \param N - The number of characters to included in the substring. If N
     /// exceeds the number of characters remaining in the string, the string
     /// suffix (starting with \arg Start) will be returned.
     StringRef substr(size_t Start, size_t N = npos) const {
       Start = min(Start, Length);
       return StringRef(Data + Start, min(N, Length - Start));
     }

     /// slice - Return a reference to the substring from [Start, End).
     ///
     /// \param Start - The index of the starting character in the substring; if
     /// the index is npos or greater than the length of the string then the
     /// empty substring will be returned.
     ///
     /// \param End - The index following the last character to include in the
     /// substring. If this is npos, or less than \arg Start, or exceeds the
     /// number of characters remaining in the string, the string suffix
     /// (starting with \arg Start) will be returned.
     StringRef slice(size_t Start, size_t End) const {
       Start = min(Start, Length);
       End = min(max(Start, End), Length);
       return StringRef(Data + Start, End - Start);
     }

     /// split - Split into two substrings around the first occurrence of a
     /// separator character.
     ///
     /// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
     /// such that (*this == LHS + Separator + RHS) is true and RHS is
     /// maximal. If \arg Separator is not in the string, then the result is a
     /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
     ///
     /// \param Separator - The character to split on.
     /// \return - The split substrings.
     std::pair<StringRef, StringRef> split(char Separator) const {
       size_t Idx = find(Separator);
       if (Idx == npos)
         return std::make_pair(*this, StringRef());
       return std::make_pair(slice(0, Idx), slice(Idx+1, npos));
     }

     /// split - Split into two substrings around the first occurrence of a
     /// separator string.
     ///
     /// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
     /// such that (*this == LHS + Separator + RHS) is true and RHS is
     /// maximal. If \arg Separator is not in the string, then the result is a
     /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
     ///
     /// \param Separator - The string to split on.
     /// \return - The split substrings.
     std::pair<StringRef, StringRef> split(StringRef Separator) const {
       size_t Idx = find(Separator);
       if (Idx == npos)
         return std::make_pair(*this, StringRef());
       return std::make_pair(slice(0, Idx), slice(Idx + Separator.size(), npos));
     }

     /// split - Split into substrings around the occurrences of a separator
     /// string.
     ///
     /// Each substring is stored in \arg A. If \arg MaxSplit is >= 0, at most
     /// \arg MaxSplit splits are done and consequently <= \arg MaxSplit
     /// elements are added to A.
     /// If \arg KeepEmpty is false, empty strings are not added to \arg A. They
     /// still count when considering \arg MaxSplit
     /// An useful invariant is that
     /// Separator.join(A) == *this if MaxSplit == -1 and KeepEmpty == true
     ///
     /// \param A - Where to put the substrings.
     /// \param Separator - The string to split on.
     /// \param MaxSplit - The maximum number of times the string is split.
     /// \param KeepEmpty - True if empty substring should be added.
     void split(SmallVectorImpl<StringRef> &A,
                StringRef Separator, int MaxSplit = -1,
                bool KeepEmpty = true) const;

     /// rsplit - Split into two substrings around the last occurrence of a
     /// separator character.
     ///
     /// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
     /// such that (*this == LHS + Separator + RHS) is true and RHS is
     /// minimal. If \arg Separator is not in the string, then the result is a
     /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
     ///
     /// \param Separator - The character to split on.
     /// \return - The split substrings.
     std::pair<StringRef, StringRef> rsplit(char Separator) const {
       size_t Idx = rfind(Separator);
       if (Idx == npos)
         return std::make_pair(*this, StringRef());
       return std::make_pair(slice(0, Idx), slice(Idx+1, npos));
     }

     /// @}
   };

   /// @name StringRef Comparison Operators
   /// @{

   inline bool operator==(StringRef LHS, StringRef RHS) {
     return LHS.equals(RHS);
   }

   inline bool operator!=(StringRef LHS, StringRef RHS) {
     return !(LHS == RHS);
   }

   inline bool operator<(StringRef LHS, StringRef RHS) {
     return LHS.compare(RHS) == -1;
   }

   inline bool operator<=(StringRef LHS, StringRef RHS) {
     return LHS.compare(RHS) != 1;
   }

   inline bool operator>(StringRef LHS, StringRef RHS) {
     return LHS.compare(RHS) == 1;
   }

   inline bool operator>=(StringRef LHS, StringRef RHS) {
     return LHS.compare(RHS) != -1;
   }

   inline std::string &operator+=(std::string &buffer, llvm::StringRef string) {
     return buffer.append(string.data(), string.size());
   }

   /// @}

   // StringRefs can be treated like a POD type.
   template <typename T> struct isPodLike;
   template <> struct isPodLike<StringRef> { static const bool value = true; };

 }

 #endif
	//===--- StringRef.h - Constant String Reference Wrapper --------- C++ --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//

	#ifndef LLVM_ADT_STRINGREF_H
	#define LLVM_ADT_STRINGREF_H

	#include <cassert>
	#include <cstring>
	#include <utility>
	#include <string>

	namespace llvm {
	template<typename T>
	class SmallVectorImpl;
	class APInt;

	/// StringRef - Represent a constant reference to a string, i.e. a character
	/// array and a length, which need not be null terminated.
	///
	/// This class does not own the string data, it is expected to be used in
	/// situations where the character data resides in some other buffer, whose
	/// lifetime extends past that of the StringRef. For this reason, it is not in
	/// general safe to store a StringRef.
	class StringRef {
	public:
	typedef const char *iterator;
	typedef const char *const_iterator;
	static const size_t npos = ~size_t(0);
	typedef size_t size_type;

	private:
	/// The start of the string, in an external buffer.
	const char *Data;

	/// The length of the string.
	size_t Length;

	// Workaround PR5482: nearly all gcc 4.x miscompile StringRef and std::min()
	// Changing the arg of min to be an integer, instead of a reference to an
	// integer works around this bug.
	static size_t min(size_t a, size_t b) { return a < b ? a : b; }
	static size_t max(size_t a, size_t b) { return a > b ? a : b; }

	// Workaround memcmp issue with null pointers (undefined behavior)
	// by providing a specialized version
	static int compareMemory(const char Lhs, const char Rhs, size_t Length) {
	if (Length == 0) { return 0; }
	return ::memcmp(Lhs,Rhs,Length);
	}

	public:
	/// @name Constructors
	/// @{

	/// Construct an empty string ref.
	/implicit/ StringRef() : Data(0), Length(0) {}

	/// Construct a string ref from a cstring.
	/implicit/ StringRef(const char *Str)
	: Data(Str) {
	assert(Str && "StringRef cannot be built from a NULL argument");
	Length = ::strlen(Str); // invoking strlen(NULL) is undefined behavior
	}

	/// Construct a string ref from a pointer and length.
	/implicit/ StringRef(const char *data, size_t length)
	: Data(data), Length(length) {
	assert((data \|\| length == 0) &&
	"StringRef cannot be built from a NULL argument with non-null length");
	}

	/// Construct a string ref from an std::string.
	/implicit/ StringRef(const std::string &Str)
	: Data(Str.data()), Length(Str.length()) {}

	/// @}
	/// @name Iterators
	/// @{

	iterator begin() const { return Data; }

	iterator end() const { return Data + Length; }

	/// @}
	/// @name String Operations
	/// @{

	/// data - Get a pointer to the start of the string (which may not be null
	/// terminated).
	const char *data() const { return Data; }

	/// empty - Check if the string is empty.
	bool empty() const { return Length == 0; }

	/// size - Get the string size.
	size_t size() const { return Length; }

	/// front - Get the first character in the string.
	char front() const {
	assert(!empty());
	return Data[0];
	}

	/// back - Get the last character in the string.
	char back() const {
	assert(!empty());
	return Data[Length-1];
	}

	/// equals - Check for string equality, this is more efficient than
	/// compare() when the relative ordering of inequal strings isn't needed.
	bool equals(StringRef RHS) const {
	return (Length == RHS.Length &&
	compareMemory(Data, RHS.Data, RHS.Length) == 0);
	}

	/// equals_lower - Check for string equality, ignoring case.
	bool equals_lower(StringRef RHS) const {
	return Length == RHS.Length && compare_lower(RHS) == 0;
	}

	/// compare - Compare two strings; the result is -1, 0, or 1 if this string
	/// is lexicographically less than, equal to, or greater than the \arg RHS.
	int compare(StringRef RHS) const {
	// Check the prefix for a mismatch.
	if (int Res = compareMemory(Data, RHS.Data, min(Length, RHS.Length)))
	return Res < 0 ? -1 : 1;

	// Otherwise the prefixes match, so we only need to check the lengths.
	if (Length == RHS.Length)
	return 0;
	return Length < RHS.Length ? -1 : 1;
	}

	/// compare_lower - Compare two strings, ignoring case.
	int compare_lower(StringRef RHS) const;

	/// compare_numeric - Compare two strings, treating sequences of digits as
	/// numbers.
	int compare_numeric(StringRef RHS) const;

	/// \brief Determine the edit distance between this string and another
	/// string.
	///
	/// \param Other the string to compare this string against.
	///
	/// \param AllowReplacements whether to allow character
	/// replacements (change one character into another) as a single
	/// operation, rather than as two operations (an insertion and a
	/// removal).
	///
	/// \param MaxEditDistance If non-zero, the maximum edit distance that
	/// this routine is allowed to compute. If the edit distance will exceed
	/// that maximum, returns \c MaxEditDistance+1.
	///
	/// \returns the minimum number of character insertions, removals,
	/// or (if \p AllowReplacements is \c true) replacements needed to
	/// transform one of the given strings into the other. If zero,
	/// the strings are identical.
	unsigned edit_distance(StringRef Other, bool AllowReplacements = true,
	unsigned MaxEditDistance = 0);

	/// str - Get the contents as an std::string.
	std::string str() const {
	if (Data == 0) return std::string();
	return std::string(Data, Length);
	}

	/// @}
	/// @name Operator Overloads
	/// @{

	char operator[](size_t Index) const {
	assert(Index < Length && "Invalid index!");
	return Data[Index];
	}

	/// @}
	/// @name Type Conversions
	/// @{

	operator std::string() const {
	return str();
	}

	/// @}
	/// @name String Predicates
	/// @{

	/// startswith - Check if this string starts with the given \arg Prefix.
	bool startswith(StringRef Prefix) const {
	return Length >= Prefix.Length &&
	compareMemory(Data, Prefix.Data, Prefix.Length) == 0;
	}

	/// endswith - Check if this string ends with the given \arg Suffix.
	bool endswith(StringRef Suffix) const {
	return Length >= Suffix.Length &&
	compareMemory(end() - Suffix.Length, Suffix.Data, Suffix.Length) == 0;
	}

	/// @}
	/// @name String Searching
	/// @{

	/// find - Search for the first character \arg C in the string.
	///
	/// \return - The index of the first occurrence of \arg C, or npos if not
	/// found.
	size_t find(char C, size_t From = 0) const {
	for (size_t i = min(From, Length), e = Length; i != e; ++i)
	if (Data[i] == C)
	return i;
	return npos;
	}

	/// find - Search for the first string \arg Str in the string.
	///
	/// \return - The index of the first occurrence of \arg Str, or npos if not
	/// found.
	size_t find(StringRef Str, size_t From = 0) const;

	/// rfind - Search for the last character \arg C in the string.
	///
	/// \return - The index of the last occurrence of \arg C, or npos if not
	/// found.
	size_t rfind(char C, size_t From = npos) const {
	From = min(From, Length);
	size_t i = From;
	while (i != 0) {
	--i;
	if (Data[i] == C)
	return i;
	}
	return npos;
	}

	/// rfind - Search for the last string \arg Str in the string.
	///
	/// \return - The index of the last occurrence of \arg Str, or npos if not
	/// found.
	size_t rfind(StringRef Str) const;

	/// find_first_of - Find the first character in the string that is \arg C,
	/// or npos if not found. Same as find.
	size_type find_first_of(char C, size_t From = 0) const {
	return find(C, From);
	}

	/// find_first_of - Find the first character in the string that is in \arg
	/// Chars, or npos if not found.
	///
	/// Note: O(size() + Chars.size())
	size_type find_first_of(StringRef Chars, size_t From = 0) const;

	/// find_first_not_of - Find the first character in the string that is not
	/// \arg C or npos if not found.
	size_type find_first_not_of(char C, size_t From = 0) const;

	/// find_first_not_of - Find the first character in the string that is not
	/// in the string \arg Chars, or npos if not found.
	///
	/// Note: O(size() + Chars.size())
	size_type find_first_not_of(StringRef Chars, size_t From = 0) const;

	/// find_last_of - Find the last character in the string that is \arg C, or
	/// npos if not found.
	size_type find_last_of(char C, size_t From = npos) const {
	return rfind(C, From);
	}

	/// find_last_of - Find the last character in the string that is in \arg C,
	/// or npos if not found.
	///
	/// Note: O(size() + Chars.size())
	size_type find_last_of(StringRef Chars, size_t From = npos) const;

	/// @}
	/// @name Helpful Algorithms
	/// @{

	/// count - Return the number of occurrences of \arg C in the string.
	size_t count(char C) const {
	size_t Count = 0;
	for (size_t i = 0, e = Length; i != e; ++i)
	if (Data[i] == C)
	++Count;
	return Count;
	}

	/// count - Return the number of non-overlapped occurrences of \arg Str in
	/// the string.
	size_t count(StringRef Str) const;

	/// getAsInteger - Parse the current string as an integer of the specified
	/// radix. If Radix is specified as zero, this does radix autosensing using
	/// extended C rules: 0 is octal, 0x is hex, 0b is binary.
	///
	/// If the string is invalid or if only a subset of the string is valid,
	/// this returns true to signify the error. The string is considered
	/// erroneous if empty.
	///
	bool getAsInteger(unsigned Radix, long long &Result) const;
	bool getAsInteger(unsigned Radix, unsigned long long &Result) const;
	bool getAsInteger(unsigned Radix, int &Result) const;
	bool getAsInteger(unsigned Radix, unsigned &Result) const;

	// TODO: Provide overloads for int/unsigned that check for overflow.

	/// getAsInteger - Parse the current string as an integer of the
	/// specified radix, or of an autosensed radix if the radix given
	/// is 0. The current value in Result is discarded, and the
	/// storage is changed to be wide enough to store the parsed
	/// integer.
	///
	/// Returns true if the string does not solely consist of a valid
	/// non-empty number in the appropriate base.
	///
	/// APInt::fromString is superficially similar but assumes the
	/// string is well-formed in the given radix.
	bool getAsInteger(unsigned Radix, APInt &Result) const;

	/// @}
	/// @name Substring Operations
	/// @{

	/// substr - Return a reference to the substring from [Start, Start + N).
	///
	/// \param Start - The index of the starting character in the substring; if
	/// the index is npos or greater than the length of the string then the
	/// empty substring will be returned.
	///
	/// \param N - The number of characters to included in the substring. If N
	/// exceeds the number of characters remaining in the string, the string
	/// suffix (starting with \arg Start) will be returned.
	StringRef substr(size_t Start, size_t N = npos) const {
	Start = min(Start, Length);
	return StringRef(Data + Start, min(N, Length - Start));
	}

	/// slice - Return a reference to the substring from [Start, End).
	///
	/// \param Start - The index of the starting character in the substring; if
	/// the index is npos or greater than the length of the string then the
	/// empty substring will be returned.
	///
	/// \param End - The index following the last character to include in the
	/// substring. If this is npos, or less than \arg Start, or exceeds the
	/// number of characters remaining in the string, the string suffix
	/// (starting with \arg Start) will be returned.
	StringRef slice(size_t Start, size_t End) const {
	Start = min(Start, Length);
	End = min(max(Start, End), Length);
	return StringRef(Data + Start, End - Start);
	}

	/// split - Split into two substrings around the first occurrence of a
	/// separator character.
	///
	/// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
	/// such that (*this == LHS + Separator + RHS) is true and RHS is
	/// maximal. If \arg Separator is not in the string, then the result is a
	/// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
	///
	/// \param Separator - The character to split on.
	/// \return - The split substrings.
	std::pair<StringRef, StringRef> split(char Separator) const {
	size_t Idx = find(Separator);
	if (Idx == npos)
	return std::make_pair(*this, StringRef());
	return std::make_pair(slice(0, Idx), slice(Idx+1, npos));
	}

	/// split - Split into two substrings around the first occurrence of a
	/// separator string.
	///
	/// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
	/// such that (*this == LHS + Separator + RHS) is true and RHS is
	/// maximal. If \arg Separator is not in the string, then the result is a
	/// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
	///
	/// \param Separator - The string to split on.
	/// \return - The split substrings.
	std::pair<StringRef, StringRef> split(StringRef Separator) const {
	size_t Idx = find(Separator);
	if (Idx == npos)
	return std::make_pair(*this, StringRef());
	return std::make_pair(slice(0, Idx), slice(Idx + Separator.size(), npos));
	}

	/// split - Split into substrings around the occurrences of a separator
	/// string.
	///
	/// Each substring is stored in \arg A. If \arg MaxSplit is >= 0, at most
	/// \arg MaxSplit splits are done and consequently <= \arg MaxSplit
	/// elements are added to A.
	/// If \arg KeepEmpty is false, empty strings are not added to \arg A. They
	/// still count when considering \arg MaxSplit
	/// An useful invariant is that
	/// Separator.join(A) == *this if MaxSplit == -1 and KeepEmpty == true
	///
	/// \param A - Where to put the substrings.
	/// \param Separator - The string to split on.
	/// \param MaxSplit - The maximum number of times the string is split.
	/// \param KeepEmpty - True if empty substring should be added.
	void split(SmallVectorImpl<StringRef> &A,
	StringRef Separator, int MaxSplit = -1,
	bool KeepEmpty = true) const;

	/// rsplit - Split into two substrings around the last occurrence of a
	/// separator character.
	///
	/// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
	/// such that (*this == LHS + Separator + RHS) is true and RHS is
	/// minimal. If \arg Separator is not in the string, then the result is a
	/// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
	///
	/// \param Separator - The character to split on.
	/// \return - The split substrings.
	std::pair<StringRef, StringRef> rsplit(char Separator) const {
	size_t Idx = rfind(Separator);
	if (Idx == npos)
	return std::make_pair(*this, StringRef());
	return std::make_pair(slice(0, Idx), slice(Idx+1, npos));
	}

	/// @}
	};

	/// @name StringRef Comparison Operators
	/// @{

	inline bool operator==(StringRef LHS, StringRef RHS) {
	return LHS.equals(RHS);
	}

	inline bool operator!=(StringRef LHS, StringRef RHS) {
	return !(LHS == RHS);
	}

	inline bool operator<(StringRef LHS, StringRef RHS) {
	return LHS.compare(RHS) == -1;
	}

	inline bool operator<=(StringRef LHS, StringRef RHS) {
	return LHS.compare(RHS) != 1;
	}

	inline bool operator>(StringRef LHS, StringRef RHS) {
	return LHS.compare(RHS) == 1;
	}

	inline bool operator>=(StringRef LHS, StringRef RHS) {
	return LHS.compare(RHS) != -1;
	}

	inline std::string &operator+=(std::string &buffer, llvm::StringRef string) {
	return buffer.append(string.data(), string.size());
	}

	/// @}

	// StringRefs can be treated like a POD type.
	template <typename T> struct isPodLike;
	template <> struct isPodLike<StringRef> { static const bool value = true; };

	}

	#endif