/*

 * Copyright (c) 1999

 * Silicon Graphics Computer Systems, Inc.

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Silicon Graphics makes no

 * representations about the suitability of this software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 */

#ifndef __CONCEPT_CHECKS_H

#define __CONCEPT_CHECKS_H

/*

  Use these macro like assertions, but they assert properties

  on types (usually template arguments). In technical terms they

  verify whether a type "models" a "concept".

  This set of requirements and the terminology used here is derived

  from the book "Generic Programming and the STL" by Matt Austern

  (Addison Wesley). For further information please consult that

  book. The requirements also are intended to match the ANSI/ISO C++

  standard.

  This file covers the basic concepts and the iterator concepts.

  There are several other files that provide the requirements

  for the STL containers:

    container_concepts.h

    sequence_concepts.h

    assoc_container_concepts.h

  Jeremy Siek, 1999

  TO DO:

    - some issues with regards to concept classification and mutability

      including AssociativeContianer -> ForwardContainer

      and SortedAssociativeContainer -> ReversibleContainer

    - HashedAssociativeContainer

    - Allocator

    - Function Object Concepts

  */

#ifndef _STLP_USE_CONCEPT_CHECKS

// Some compilers lack the features that are necessary for concept checks.

// On those compilers we define the concept check macros to do nothing.

#define _STLP_REQUIRES(__type_var, __concept) do {} while(0)

#define _STLP_CLASS_REQUIRES(__type_var, __concept) \

  static int  __##__type_var##_##__concept

#define _STLP_CONVERTIBLE(__type_x, __type_y) do {} while(0)

#define _STLP_REQUIRES_SAME_TYPE(__type_x, __type_y) do {} while(0)

#define _STLP_CLASS_REQUIRES_SAME_TYPE(__type_x, __type_y) \

  static int  __##__type_x##__type_y##_require_same_type

#define _STLP_GENERATOR_CHECK(__func, __ret) do {} while(0)

#define _STLP_CLASS_GENERATOR_CHECK(__func, __ret) \

  static int  __##__func##__ret##_generator_check

#define _STLP_UNARY_FUNCTION_CHECK(__func, __ret, __arg) do {} while(0)

#define _STLP_CLASS_UNARY_FUNCTION_CHECK(__func, __ret, __arg) \

  static int  __##__func##__ret##__arg##_unary_function_check

#define _STLP_BINARY_FUNCTION_CHECK(__func, __ret, __first, __second) \

  do {} while(0)

#define _STLP_CLASS_BINARY_FUNCTION_CHECK(__func, __ret, __first, __second) \

  static int  __##__func##__ret##__first##__second##_binary_function_check

#define _STLP_REQUIRES_BINARY_OP(__opname, __ret, __first, __second) \

  do {} while(0)

#define _STLP_CLASS_REQUIRES_BINARY_OP(__opname, __ret, __first, __second) \

  static int __##__opname##__ret##__first##__second##_require_binary_op

#else /* _STLP_USE_CONCEPT_CHECKS */

// This macro tests whether the template argument "__type_var"

// satisfies the requirements of "__concept".  Here is a list of concepts

// that we know how to check:

//       _Allocator

//       _Assignable

//       _DefaultConstructible

//       _EqualityComparable

//       _LessThanComparable

//       _TrivialIterator

//       _InputIterator

//       _OutputIterator

//       _ForwardIterator

//       _BidirectionalIterator

//       _RandomAccessIterator

//       _Mutable_TrivialIterator

//       _Mutable_ForwardIterator

//       _Mutable_BidirectionalIterator

//       _Mutable_RandomAccessIterator

#define _STLP_REQUIRES(__type_var, __concept) \

do { \

  void (*__x)( __type_var ) = __concept##_concept_specification< __type_var >\

    ::##__concept##_requirement_violation; __x = __x; } while (0)

// Use this to check whether type X is convertible to type Y

#define _STLP_CONVERTIBLE(__type_x, __type_y) \

do { \

  void (*__x)( __type_x , __type_y ) = _STL_CONVERT_ERROR< __type_x , \

  __type_y >::__type_X_is_not_convertible_to_type_Y; \

  __x = __x; } while (0)

// Use this to test whether two template arguments are the same type

#define _STLP_REQUIRES_SAME_TYPE(__type_x, __type_y) \

do { \

  void (*__x)( __type_x , __type_y ) = _STL_SAME_TYPE_ERROR< __type_x, \

    __type_y  >::__type_X_not_same_as_type_Y; \

  __x = __x; } while (0)

// function object checks

#define _STLP_GENERATOR_CHECK(__func, __ret) \

do { \

  __ret (*__x)( __func&) = \

     _STL_GENERATOR_ERROR< \

  __func, __ret>::__generator_requirement_violation; \

  __x = __x; } while (0)

#define _STLP_UNARY_FUNCTION_CHECK(__func, __ret, __arg) \

do { \

  __ret (*__x)( __func&, const __arg& ) = \

     _STL_UNARY_FUNCTION_ERROR< \

  __func, __ret, __arg>::__unary_function_requirement_violation; \

  __x = __x; } while (0)

#define _STLP_BINARY_FUNCTION_CHECK(__func, __ret, __first, __second) \

do { \

  __ret (*__x)( __func&, const __first&, const __second& ) = \

     _STL_BINARY_FUNCTION_ERROR< \

  __func, __ret, __first, __second>::__binary_function_requirement_violation; \

  __x = __x; } while (0)

#define _STLP_REQUIRES_BINARY_OP(__opname, __ret, __first, __second) \

    do { \

  __ret (*__x)( __first&, __second& ) = _STL_BINARY##__opname##_ERROR< \

    __ret, __first, __second>::__binary_operator_requirement_violation; \

  __ret (*__y)( const __first&, const __second& ) = \

    _STL_BINARY##__opname##_ERROR< __ret, __first, __second>:: \

      __const_binary_operator_requirement_violation; \

  __y = __y; __x = __x; } while (0)

#ifdef _STLP_NO_FUNCTION_PTR_IN_CLASS_TEMPLATE

#define _STLP_CLASS_REQUIRES(__type_var, __concept)

#define _STLP_CLASS_REQUIRES_SAME_TYPE(__type_x, __type_y)

#define _STLP_CLASS_GENERATOR_CHECK(__func, __ret)

#define _STLP_CLASS_UNARY_FUNCTION_CHECK(__func, __ret, __arg)

#define _STLP_CLASS_BINARY_FUNCTION_CHECK(__func, __ret, __first, __second)

#define _STLP_CLASS_REQUIRES_BINARY_OP(__opname, __ret, __first, __second)

#else

// Use this macro inside of template classes, where you would

// like to place requirements on the template arguments to the class

// Warning: do not pass pointers and such (e.g. T*) in as the __type_var,

// since the type_var is used to construct identifiers. Instead typedef

// the pointer type, then use the typedef name for the __type_var.

#define _STLP_CLASS_REQUIRES(__type_var, __concept) \

  typedef void (* __func##__type_var##__concept)( __type_var ); \

  template <__func##__type_var##__concept _Tp1> \

  struct __dummy_struct_##__type_var##__concept { }; \

  static __dummy_struct_##__type_var##__concept< \

    __concept##_concept_specification< \

      __type_var>::__concept##_requirement_violation>  \

  __dummy_ptr_##__type_var##__concept

#define _STLP_CLASS_REQUIRES_SAME_TYPE(__type_x, __type_y) \

  typedef void (* __func_##__type_x##__type_y##same_type)( __type_x, \

                                                            __type_y ); \

  template < __func_##__type_x##__type_y##same_type _Tp1> \

  struct __dummy_struct_##__type_x##__type_y##_same_type { }; \

  static __dummy_struct_##__type_x##__type_y##_same_type< \

    _STL_SAME_TYPE_ERROR<__type_x, __type_y>::__type_X_not_same_as_type_Y>  \

  __dummy_ptr_##__type_x##__type_y##_same_type

#define _STLP_CLASS_GENERATOR_CHECK(__func, __ret) \

  typedef __ret (* __f_##__func##__ret##_generator)( __func& ); \

  template <__f_##__func##__ret##_generator _Tp1> \

  struct __dummy_struct_##__func##__ret##_generator { }; \

  static __dummy_struct_##__func##__ret##_generator< \

    _STL_GENERATOR_ERROR< \

      __func, __ret>::__generator_requirement_violation>  \

  __dummy_ptr_##__func##__ret##_generator

#define _STLP_CLASS_UNARY_FUNCTION_CHECK(__func, __ret, __arg) \

  typedef __ret (* __f_##__func##__ret##__arg##_unary_check)( __func&, \

                                                         const __arg& ); \

  template <__f_##__func##__ret##__arg##_unary_check _Tp1> \

  struct __dummy_struct_##__func##__ret##__arg##_unary_check { }; \

  static __dummy_struct_##__func##__ret##__arg##_unary_check< \

    _STL_UNARY_FUNCTION_ERROR< \

      __func, __ret, __arg>::__unary_function_requirement_violation>  \

  __dummy_ptr_##__func##__ret##__arg##_unary_check

#define _STLP_CLASS_BINARY_FUNCTION_CHECK(__func, __ret, __first, __second) \

  typedef __ret (* __f_##__func##__ret##__first##__second##_binary_check)( __func&, const __first&,\

                                                    const __second& ); \

  template <__f_##__func##__ret##__first##__second##_binary_check _Tp1> \

  struct __dummy_struct_##__func##__ret##__first##__second##_binary_check { }; \

  static __dummy_struct_##__func##__ret##__first##__second##_binary_check< \

    _STL_BINARY_FUNCTION_ERROR<__func, __ret, __first, __second>:: \

  __binary_function_requirement_violation>  \

  __dummy_ptr_##__func##__ret##__first##__second##_binary_check

#define _STLP_CLASS_REQUIRES_BINARY_OP(__opname, __ret, __first, __second) \

  typedef __ret (* __f_##__func##__ret##__first##__second##_binary_op)(const __first&, \

                                                    const __second& ); \

  template <__f_##__func##__ret##__first##__second##_binary_op _Tp1> \

  struct __dummy_struct_##__func##__ret##__first##__second##_binary_op { }; \

  static __dummy_struct_##__func##__ret##__first##__second##_binary_op< \

    _STL_BINARY##__opname##_ERROR<__ret, __first, __second>:: \

  __binary_operator_requirement_violation>  \

  __dummy_ptr_##__func##__ret##__first##__second##_binary_op

#endif

/* helper class for finding non-const version of a type. Need to have

   something to assign to etc. when testing constant iterators. */

template <class _Tp>

struct _Mutable_trait {

  typedef _Tp _Type;

};

template <class _Tp>

struct _Mutable_trait<const _Tp> {

  typedef _Tp _Type;

};

/* helper function for avoiding compiler warnings about unused variables */

template <class _Type>

void __sink_unused_warning(_Type) { }

template <class _TypeX, class _TypeY>

struct _STL_CONVERT_ERROR {

  static void

  __type_X_is_not_convertible_to_type_Y(_TypeX __x, _TypeY) {

    _TypeY __y = __x;

    __sink_unused_warning(__y);

  }

};

template <class _Type> struct __check_equal { };

template <class _TypeX, class _TypeY>

struct _STL_SAME_TYPE_ERROR {

  static void

  __type_X_not_same_as_type_Y(_TypeX , _TypeY ) { 

    __check_equal<_TypeX> t1 = __check_equal<_TypeY>();

  }

};

// Some Functon Object Checks

template <class _Func, class _Ret>

struct _STL_GENERATOR_ERROR {

  static _Ret __generator_requirement_violation(_Func& __f) {

    return __f();

  }

};

template <class _Func>

struct _STL_GENERATOR_ERROR<_Func, void> {

  static void __generator_requirement_violation(_Func& __f) {

    __f();

  }

};

template <class _Func, class _Ret, class _Arg>

struct _STL_UNARY_FUNCTION_ERROR {

  static _Ret

  __unary_function_requirement_violation(_Func& __f,

                                          const _Arg& __arg) {

    return __f(__arg);

  }

};

template <class _Func, class _Arg>

struct _STL_UNARY_FUNCTION_ERROR<_Func, void, _Arg> {

  static void

  __unary_function_requirement_violation(_Func& __f,

                                          const _Arg& __arg) {

    __f(__arg);

  }

};

template <class _Func, class _Ret, class _First, class _Second>

struct _STL_BINARY_FUNCTION_ERROR {

  static _Ret

  __binary_function_requirement_violation(_Func& __f,

                                          const _First& __first, 

                                          const _Second& __second) {

    return __f(__first, __second);

  }

};

template <class _Func, class _First, class _Second>

struct _STL_BINARY_FUNCTION_ERROR<_Func, void, _First, _Second> {

  static void

  __binary_function_requirement_violation(_Func& __f,

                                          const _First& __first, 

                                          const _Second& __second) {

    __f(__first, __second);

  }

};

#define _STLP_DEFINE_BINARY_OP_CHECK(_OP, _NAME) \

template <class _Ret, class _First, class _Second> \

struct _STL_BINARY##_NAME##_ERROR { \

  static _Ret \

  __const_binary_operator_requirement_violation(const _First& __first,  \

                                                const _Second& __second) { \

    return __first _OP __second; \

  } \

  static _Ret \

  __binary_operator_requirement_violation(_First& __first,  \

                                          _Second& __second) { \

    return __first _OP __second; \

  } \

}

_STLP_DEFINE_BINARY_OP_CHECK(==, _OP_EQUAL);

_STLP_DEFINE_BINARY_OP_CHECK(!=, _OP_NOT_EQUAL);

_STLP_DEFINE_BINARY_OP_CHECK(<, _OP_LESS_THAN);

_STLP_DEFINE_BINARY_OP_CHECK(<=, _OP_LESS_EQUAL);

_STLP_DEFINE_BINARY_OP_CHECK(>, _OP_GREATER_THAN);

_STLP_DEFINE_BINARY_OP_CHECK(>=, _OP_GREATER_EQUAL);

_STLP_DEFINE_BINARY_OP_CHECK(+, _OP_PLUS);

_STLP_DEFINE_BINARY_OP_CHECK(*, _OP_TIMES);

_STLP_DEFINE_BINARY_OP_CHECK(/, _OP_DIVIDE);

_STLP_DEFINE_BINARY_OP_CHECK(-, _OP_SUBTRACT);

_STLP_DEFINE_BINARY_OP_CHECK(%, _OP_MOD);

// ...

// TODO, add unary operators (prefix and postfix)

/*

  The presence of this class is just to trick EDG into displaying

  these error messages before any other errors. Without the

  classes, the errors in the functions get reported after

  other class errors deep inside the library. The name

  choice just makes for an eye catching error message :)

 */

struct _STL_ERROR {

  template <class _Type>

  static _Type

  __default_constructor_requirement_violation(_Type) {

    return _Type();

  }

  template <class _Type>

  static _Type

  __assignment_operator_requirement_violation(_Type __a) {

    __a = __a;

    return __a;

  }

  template <class _Type>

  static _Type

  __copy_constructor_requirement_violation(_Type __a) {

    _Type __c(__a);

    return __c;

  }

  template <class _Type>

  static _Type

  __const_parameter_required_for_copy_constructor(_Type /* __a */, 

                                                  const _Type& __b) {

    _Type __c(__b);

    return __c;

  }

  template <class _Type>

  static _Type

  __const_parameter_required_for_assignment_operator(_Type __a, 

                                                     const _Type& __b) {

    __a = __b;

    return __a;

  }

  template <class _Type>

  static _Type

  __less_than_comparable_requirement_violation(_Type __a, _Type __b) {

    if (__a < __b || __a > __b || __a <= __b || __a >= __b) return __a;

    return __b;

  }

  template <class _Type>

  static _Type

  __equality_comparable_requirement_violation(_Type __a, _Type __b) {

    if (__a == __b || __a != __b) return __a;

    return __b;

  }

  template <class _Iterator>

  static void

  __dereference_operator_requirement_violation(_Iterator __i) {

    __sink_unused_warning(*__i);

  }

  template <class _Iterator>

  static void

  __dereference_operator_and_assignment_requirement_violation(_Iterator __i) {

    *__i = *__i;

  }

  template <class _Iterator>

  static void

  __preincrement_operator_requirement_violation(_Iterator __i) {

    ++__i;

  }

  template <class _Iterator>

  static void

  __postincrement_operator_requirement_violation(_Iterator __i) {

    __i++;

  }

  template <class _Iterator>

  static void

  __predecrement_operator_requirement_violation(_Iterator __i) {

    --__i;

  }

  template <class _Iterator>

  static void

  __postdecrement_operator_requirement_violation(_Iterator __i) {

    __i--;

  }

  template <class _Iterator, class _Type>

  static void

  __postincrement_operator_and_assignment_requirement_violation(_Iterator __i,

                                                                _Type __t) {

    *__i++ = __t;

  }

  template <class _Iterator, class _Distance>

  static _Iterator

  __iterator_addition_assignment_requirement_violation(_Iterator __i, 

                                                       _Distance __n) {

    __i += __n;

    return __i;

  }

  template <class _Iterator, class _Distance>

  static _Iterator

  __iterator_addition_requirement_violation(_Iterator __i, _Distance __n) {

    __i = __i + __n;

    __i = __n + __i;

    return __i;

  }

  template <class _Iterator, class _Distance>

  static _Iterator

  __iterator_subtraction_assignment_requirement_violation(_Iterator __i,

                                                          _Distance __n) {

    __i -= __n;

    return __i;

  }

  template <class _Iterator, class _Distance>

  static _Iterator

  __iterator_subtraction_requirement_violation(_Iterator __i, _Distance __n) {

    __i = __i - __n;

    return __i;

  }

  template <class _Iterator, class _Distance>

  static _Distance

  __difference_operator_requirement_violation(_Iterator __i, _Iterator __j,

                                              _Distance __n) {

    __n = __i - __j;

    return __n;

  }

  template <class _Exp, class _Type, class _Distance>

  static _Type

  __element_access_operator_requirement_violation(_Exp __x, _Type*,

                                                  _Distance __n) {

    return __x[__n];

  }

  template <class _Exp, class _Type, class _Distance>

  static void

  __element_assignment_operator_requirement_violation(_Exp __x,

                                                      _Type* __t,

                                                      _Distance __n) {

    __x[__n] = *__t;

  }

}; /* _STL_ERROR */

/* Associated Type Requirements */

_STLP_BEGIN_NAMESPACE

template <class _Iterator> struct iterator_traits;

_STLP_END_NAMESPACE

template <class _Iter> 

struct __value_type_type_definition_requirement_violation {

  typedef typename __STD::iterator_traits<_Iter>::value_type value_type;

};

template <class _Iter> 

struct __difference_type_type_definition_requirement_violation {

  typedef typename __STD::iterator_traits<_Iter>::difference_type

          difference_type;

};

template <class _Iter> 

struct __reference_type_definition_requirement_violation {

  typedef typename __STD::iterator_traits<_Iter>::reference reference;

};

template <class _Iter> 

struct __pointer_type_definition_requirement_violation {

  typedef typename __STD::iterator_traits<_Iter>::pointer pointer;

};

template <class _Iter> 

struct __iterator_category_type_definition_requirement_violation {

  typedef typename __STD::iterator_traits<_Iter>::iterator_category 

          iterator_category;

};

/* Assignable Requirements */

template <class _Type>

struct _Assignable_concept_specification {

  static void _Assignable_requirement_violation(_Type __a) {