//

// (C) Copyright Jeremy Siek 2000.

// 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)

//

// Revision History:

//   05 May   2001: Workarounds for HP aCC from Thomas Matelich. (Jeremy Siek)

//   02 April 2001: Removed limits header altogether. (Jeremy Siek)

//   01 April 2001: Modified to use new <boost/limits.hpp> header. (JMaddock)

//

// See http://www.boost.org/libs/concept_check for documentation.

#ifndef BOOST_CONCEPT_CHECKS_HPP

#define BOOST_CONCEPT_CHECKS_HPP

#include <boost/config.hpp>

#include <boost/iterator.hpp>

#include <boost/type_traits/conversion_traits.hpp>

#include <utility>

#include <boost/type_traits/conversion_traits.hpp>

#include <boost/static_assert.hpp>

#include <boost/mpl/identity.hpp>

#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 || defined(__BORLANDC__)

#define BOOST_FPTR

#else

#define BOOST_FPTR &

#endif

namespace boost {

/*

  "inline" is used for ignore_unused_variable_warning()

   and function_requires() to make sure there is no

   overhead with g++.

 */

template <class T> inline void ignore_unused_variable_warning(const T&) { }

// the unused, defaulted parameter is a workaround for MSVC and Compaq C++

template <class Concept>

inline void function_requires(mpl::identity<Concept>* = 0)

{

#if !defined(NDEBUG)

  void (Concept::*x)() = BOOST_FPTR Concept::constraints;

  ignore_unused_variable_warning(x);

#endif

}

#define BOOST_CLASS_REQUIRE(type_var, ns, concept) \

  typedef void (ns::concept <type_var>::* func##type_var##concept)(); \

  template <func##type_var##concept Tp1_> \

  struct concept_checking_##type_var##concept { }; \

  typedef concept_checking_##type_var##concept< \

    BOOST_FPTR ns::concept<type_var>::constraints> \

    concept_checking_typedef_##type_var##concept

#define BOOST_CLASS_REQUIRE2(type_var1, type_var2, ns, concept) \

  typedef void (ns::concept <type_var1,type_var2>::* \

     func##type_var1##type_var2##concept)(); \

  template <func##type_var1##type_var2##concept Tp1_> \

  struct concept_checking_##type_var1##type_var2##concept { }; \

  typedef concept_checking_##type_var1##type_var2##concept< \

    BOOST_FPTR ns::concept<type_var1,type_var2>::constraints> \

    concept_checking_typedef_##type_var1##type_var2##concept

#define BOOST_CLASS_REQUIRE3(tv1, tv2, tv3, ns, concept) \

  typedef void (ns::concept <tv1,tv2,tv3>::* \

     func##tv1##tv2##tv3##concept)(); \

  template <func##tv1##tv2##tv3##concept Tp1_> \

  struct concept_checking_##tv1##tv2##tv3##concept { }; \

  typedef concept_checking_##tv1##tv2##tv3##concept< \

    BOOST_FPTR ns::concept<tv1,tv2,tv3>::constraints> \

    concept_checking_typedef_##tv1##tv2##tv3##concept

#define BOOST_CLASS_REQUIRE4(tv1, tv2, tv3, tv4, ns, concept) \

  typedef void (ns::concept <tv1,tv2,tv3,tv4>::* \

     func##tv1##tv2##tv3##tv4##concept)(); \

  template <func##tv1##tv2##tv3##tv4##concept Tp1_> \

  struct concept_checking_##tv1##tv2##tv3##tv4##concept { }; \

  typedef concept_checking_##tv1##tv2##tv3##tv4##concept< \

    BOOST_FPTR ns::concept<tv1,tv2,tv3,tv4>::constraints> \

    concept_checking_typedef_##tv1##tv2##tv3##tv4##concept

// NOTE: The BOOST_CLASS_REQUIRES (with an 'S' at the end) is deprecated.

// The BOOST_CLASS_REQUIRES macros use function pointers as

// template parameters, which VC++ does not support.

#if defined(BOOST_NO_FUNCTION_PTR_TEMPLATE_PARAMETERS)

#define BOOST_CLASS_REQUIRES(type_var, concept)

#define BOOST_CLASS_REQUIRES2(type_var1, type_var2, concept)

#define BOOST_CLASS_REQUIRES3(type_var1, type_var2, type_var3, concept)

#define BOOST_CLASS_REQUIRES4(type_var1, type_var2, type_var3, type_var4, concept)

#else

#define BOOST_CLASS_REQUIRES(type_var, concept) \

  typedef void (concept <type_var>::* func##type_var##concept)(); \

  template <func##type_var##concept Tp1_> \

  struct concept_checking_##type_var##concept { }; \

  typedef concept_checking_##type_var##concept< \

    BOOST_FPTR concept <type_var>::constraints> \

    concept_checking_typedef_##type_var##concept

#define BOOST_CLASS_REQUIRES2(type_var1, type_var2, concept) \

  typedef void (concept <type_var1,type_var2>::* func##type_var1##type_var2##concept)(); \

  template <func##type_var1##type_var2##concept Tp1_> \

  struct concept_checking_##type_var1##type_var2##concept { }; \

  typedef concept_checking_##type_var1##type_var2##concept< \

    BOOST_FPTR concept <type_var1,type_var2>::constraints> \

    concept_checking_typedef_##type_var1##type_var2##concept

#define BOOST_CLASS_REQUIRES3(type_var1, type_var2, type_var3, concept) \

  typedef void (concept <type_var1,type_var2,type_var3>::* func##type_var1##type_var2##type_var3##concept)(); \

  template <func##type_var1##type_var2##type_var3##concept Tp1_> \

  struct concept_checking_##type_var1##type_var2##type_var3##concept { }; \

  typedef concept_checking_##type_var1##type_var2##type_var3##concept< \

    BOOST_FPTR concept <type_var1,type_var2,type_var3>::constraints>  \

  concept_checking_typedef_##type_var1##type_var2##type_var3##concept

#define BOOST_CLASS_REQUIRES4(type_var1, type_var2, type_var3, type_var4, concept) \

  typedef void (concept <type_var1,type_var2,type_var3,type_var4>::* func##type_var1##type_var2##type_var3##type_var4##concept)(); \

  template <func##type_var1##type_var2##type_var3##type_var4##concept Tp1_> \

  struct concept_checking_##type_var1##type_var2##type_var3##type_var4##concept { }; \

  typedef concept_checking_##type_var1##type_var2##type_var3##type_var4##concept< \

    BOOST_FPTR concept <type_var1,type_var2,type_var3,type_var4>::constraints>  \

    concept_checking_typedef_##type_var1##type_var2##type_var3##type_var4##concept

#endif

#if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

template <class T, class U>

struct require_same { };

template <class T>

struct require_same<T,T> { typedef T type; };

#else

// This version does not perform checking, but will not do any harm.

template <class T, class U>

struct require_same { typedef T type; };

#endif

  template <class T>

  struct IntegerConcept {

    void constraints() { 

#if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

      x.error_type_must_be_an_integer_type();

#endif      

    }

    T x;

  };

#if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

  template <> struct IntegerConcept<short> { void constraints() {} };

  template <> struct IntegerConcept<unsigned short> { void constraints() {} };

  template <> struct IntegerConcept<int> { void constraints() {} };

  template <> struct IntegerConcept<unsigned int> { void constraints() {} };

  template <> struct IntegerConcept<long> { void constraints() {} };

  template <> struct IntegerConcept<unsigned long> { void constraints() {} };

  // etc.

#endif      

  template <class T>

  struct SignedIntegerConcept {

    void constraints() { 

#if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

      x.error_type_must_be_a_signed_integer_type();

#endif      

    }

    T x;

  };

#if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

  template <> struct SignedIntegerConcept<short> { void constraints() {} };

  template <> struct SignedIntegerConcept<int> { void constraints() {} };

  template <> struct SignedIntegerConcept<long> { void constraints() {} };

# if defined(BOOST_HAS_LONG_LONG)

  template <> struct SignedIntegerConcept< ::boost::long_long_type> { void constraints() {} };

# endif

  // etc.

#endif      

  template <class T>

  struct UnsignedIntegerConcept {

    void constraints() { 

#if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

      x.error_type_must_be_an_unsigned_integer_type();

#endif      

    }

    T x;

  };

#if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

  template <> struct UnsignedIntegerConcept<unsigned short>

    { void constraints() {} };

  template <> struct UnsignedIntegerConcept<unsigned int>

    { void constraints() {} };

  template <> struct UnsignedIntegerConcept<unsigned long>

    { void constraints() {} };

  // etc.

#endif      

  //===========================================================================

  // Basic Concepts

  template <class TT>

  struct DefaultConstructibleConcept

  {

    void constraints() {

      TT a;               // require default constructor

      ignore_unused_variable_warning(a);

    }

  };

  template <class TT>

  struct AssignableConcept

  {

    void constraints() {

#if !defined(_ITERATOR_) // back_insert_iterator broken for VC++ STL

      a = a;              // require assignment operator

#endif

      const_constraints(a);

    }

    void const_constraints(const TT& b) {

#if !defined(_ITERATOR_) // back_insert_iterator broken for VC++ STL

      a = b;              // const required for argument to assignment

#endif

    }

    TT a;

  };

  template <class TT>

  struct CopyConstructibleConcept

  {

    void constraints() {

      TT a(b);            // require copy constructor

      TT* ptr = &a;       // require address of operator

      const_constraints(a);

      ignore_unused_variable_warning(ptr);

    }

    void const_constraints(const TT& a) {

      TT c(a);            // require const copy constructor

      const TT* ptr = &a; // require const address of operator

      ignore_unused_variable_warning(c);

      ignore_unused_variable_warning(ptr);

    }

    TT b;

  };

  // The SGI STL version of Assignable requires copy constructor and operator=

  template <class TT>

  struct SGIAssignableConcept

  {

    void constraints() {

      TT b(a);

#if !defined(_ITERATOR_) // back_insert_iterator broken for VC++ STL

      a = a;              // require assignment operator

#endif

      const_constraints(a);

      ignore_unused_variable_warning(b);

    }

    void const_constraints(const TT& b) {

      TT c(b);

#if !defined(_ITERATOR_) // back_insert_iterator broken for VC++ STL

      a = b;              // const required for argument to assignment

#endif

      ignore_unused_variable_warning(c);

    }

    TT a;

  };

  template <class X, class Y>

  struct ConvertibleConcept

  {

    void constraints() {

      Y y = x;

      ignore_unused_variable_warning(y);

    }

    X x;

  };

  // The C++ standard requirements for many concepts talk about return

  // types that must be "convertible to bool".  The problem with this

  // requirement is that it leaves the door open for evil proxies that

  // define things like operator|| with strange return types.  Two

  // possible solutions are:

  // 1) require the return type to be exactly bool

  // 2) stay with convertible to bool, and also

  //    specify stuff about all the logical operators.

  // For now we just test for convertible to bool.

  template <class TT>

  void require_boolean_expr(const TT& t) {

    bool x = t;

    ignore_unused_variable_warning(x);

  }

  template <class TT>

  struct EqualityComparableConcept

  {

    void constraints() {

      require_boolean_expr(a == b);

      require_boolean_expr(a != b);

    }

    TT a, b;

  };

  template <class TT>

  struct LessThanComparableConcept

  {

    void constraints() {

      require_boolean_expr(a < b);

    }

    TT a, b;

  };

  // This is equivalent to SGI STL's LessThanComparable.

  template <class TT>

  struct ComparableConcept

  {

    void constraints() {

      require_boolean_expr(a < b);

      require_boolean_expr(a > b);

      require_boolean_expr(a <= b);

      require_boolean_expr(a >= b);

    }

    TT a, b;

  };

#define BOOST_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(OP,NAME) \

  template <class First, class Second> \

  struct NAME { \

    void constraints() { (void)constraints_(); } \

    bool constraints_() {  \

      return  a OP b; \

    } \

    First a; \

    Second b; \

  }

#define BOOST_DEFINE_BINARY_OPERATOR_CONSTRAINT(OP,NAME) \

  template <class Ret, class First, class Second> \

  struct NAME { \

    void constraints() { (void)constraints_(); } \

    Ret constraints_() {  \

      return a OP b; \

    } \

    First a; \

    Second b; \

  }

  BOOST_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(==, EqualOpConcept);

  BOOST_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(!=, NotEqualOpConcept);

  BOOST_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(<, LessThanOpConcept);

  BOOST_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(<=, LessEqualOpConcept);

  BOOST_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(>, GreaterThanOpConcept);

  BOOST_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(>=, GreaterEqualOpConcept);

  BOOST_DEFINE_BINARY_OPERATOR_CONSTRAINT(+, PlusOpConcept);

  BOOST_DEFINE_BINARY_OPERATOR_CONSTRAINT(*, TimesOpConcept);

  BOOST_DEFINE_BINARY_OPERATOR_CONSTRAINT(/, DivideOpConcept);

  BOOST_DEFINE_BINARY_OPERATOR_CONSTRAINT(-, SubtractOpConcept);

  BOOST_DEFINE_BINARY_OPERATOR_CONSTRAINT(%, ModOpConcept);

  //===========================================================================

  // Function Object Concepts

  template <class Func, class Return>

  struct GeneratorConcept

  {

    void constraints() {

      const Return& r = f();   // require operator() member function

      ignore_unused_variable_warning(r);

    }

    Func f;

  };

#if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

  template <class Func>

  struct GeneratorConcept<Func,void>

  {

    void constraints() {

      f();              // require operator() member function

    }

    Func f;

  };

#endif

  template <class Func, class Return, class Arg>

  struct UnaryFunctionConcept

  {

    // required in case any of our template args are const-qualified:

    UnaryFunctionConcept();

    void constraints() {

      r = f(arg); // require operator()

    }

    Func f;

    Arg arg;

    Return r;

  };

#if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

  template <class Func, class Arg>

  struct UnaryFunctionConcept<Func, void, Arg> {

    void constraints() { 

      f(arg);                 // require operator()

    }

    Func f;

    Arg arg;

  };

#endif

  template <class Func, class Return, class First, class Second>

  struct BinaryFunctionConcept

  {

    void constraints() { 

      r = f(first, second); // require operator()

    }

    Func f;

    First first;

    Second second;

    Return r;

  };

#if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

  template <class Func, class First, class Second>

  struct BinaryFunctionConcept<Func, void, First, Second>

  {

    void constraints() {

      f(first, second); // require operator()

    }

    Func f;

    First first;

    Second second;

  };

#endif

  template <class Func, class Arg>

  struct UnaryPredicateConcept

  {

    void constraints() {

      require_boolean_expr(f(arg)); // require operator() returning bool

    }

    Func f;

    Arg arg;

  };

  template <class Func, class First, class Second>

  struct BinaryPredicateConcept

  {

    void constraints() {

      require_boolean_expr(f(a, b)); // require operator() returning bool

    }

    Func f;

    First a;

    Second b;

  };

  // use this when functor is used inside a container class like std::set

  template <class Func, class First, class Second>

  struct Const_BinaryPredicateConcept {

    void constraints() { 

      const_constraints(f);

    }

    void const_constraints(const Func& fun) {

      function_requires<BinaryPredicateConcept<Func, First, Second> >();

      // operator() must be a const member function

      require_boolean_expr(fun(a, b));

    }

    Func f;

    First a;

    Second b;

  };

  template <class Func, class Return>

  struct AdaptableGeneratorConcept

  {

    void constraints() {

      typedef typename Func::result_type result_type;

      BOOST_STATIC_ASSERT((is_convertible<result_type, Return>::value));

      function_requires< GeneratorConcept<Func, result_type> >();

    }

  };

  template <class Func, class Return, class Arg>

  struct AdaptableUnaryFunctionConcept

  {

    void constraints() {

      typedef typename Func::argument_type argument_type;

      typedef typename Func::result_type result_type;

      BOOST_STATIC_ASSERT((is_convertible<result_type, Return>::value));

      BOOST_STATIC_ASSERT((is_convertible<Arg, argument_type>::value));

      function_requires< UnaryFunctionConcept<Func, result_type, argument_type> >();

    }

  };

  template <class Func, class Return, class First, class Second>

  struct AdaptableBinaryFunctionConcept

  {

    void constraints() {

      typedef typename Func::first_argument_type first_argument_type;

      typedef typename Func::second_argument_type second_argument_type;

      typedef typename Func::result_type result_type;

      BOOST_STATIC_ASSERT((is_convertible<result_type, Return>::value));

      BOOST_STATIC_ASSERT((is_convertible<First, first_argument_type>::value));

      BOOST_STATIC_ASSERT((is_convertible<Second, second_argument_type>::value));

      function_requires< BinaryFunctionConcept<Func, result_type, 

        first_argument_type, second_argument_type> >();

    }

  };

  template <class Func, class Arg>

  struct AdaptablePredicateConcept

  {

    void constraints() {

      function_requires< UnaryPredicateConcept<Func, Arg> >();

      function_requires< AdaptableUnaryFunctionConcept<Func, bool, Arg> >();

    }

  };

  template <class Func, class First, class Second>

  struct AdaptableBinaryPredicateConcept

  {

    void constraints() {