boost_concept_check.h

俄罗斯高人Mamaich的Pocket gcc编译器（运行在PocketPC上）的全部源代码。

//
// (C) Copyright Jeremy Siek 2000. Permission to copy, use, modify,
// sell and distribute this software is granted provided this
// copyright notice appears in all copies. This software is provided
// "as is" without express or implied warranty, and with no claim as
// to its suitability for any purpose.
//

// GCC Note:  based on version 1.12.0 of the Boost library.

/** @file boost_concept_check.h
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

#ifndef _GLIBCPP_BOOST_CONCEPT_CHECK
#define _GLIBCPP_BOOST_CONCEPT_CHECK 1

#pragma GCC system_header
#include <cstddef>                // for ptrdiff_t, used next
#include <bits/stl_iterator_base_types.h>    // for traits and tags
#include <utility>                           // for pair<>


namespace __gnu_cxx
{

#define _IsUnused __attribute__ ((__unused__))

// When the C-C code is in use, we would like this function to do as little
// as possible at runtime, use as few resources as possible, and hopefully
// be elided out of existence... hmmm.
template <class _Concept>
inline void __function_requires()
{
  void (_Concept::*__x)() _IsUnused = &_Concept::__constraints;
}


// ??? Should the "concept_checking*" structs begin with more than _ ?
#define _GLIBCPP_CLASS_REQUIRES(_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< \
    &_ns::_concept <_type_var>::__constraints> \
    _concept_checking_typedef##_type_var##_concept

#define _GLIBCPP_CLASS_REQUIRES2(_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< \
    &_ns::_concept <_type_var1,_type_var2>::__constraints> \
    _concept_checking_typedef##_type_var1##_type_var2##_concept

#define _GLIBCPP_CLASS_REQUIRES3(_type_var1, _type_var2, _type_var3, _ns, _concept) \
  typedef void (_ns::_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< \
    &_ns::_concept <_type_var1,_type_var2,_type_var3>::__constraints>  \
  _concept_checking_typedef##_type_var1##_type_var2##_type_var3##_concept

#define _GLIBCPP_CLASS_REQUIRES4(_type_var1, _type_var2, _type_var3, _type_var4, _ns, _concept) \
  typedef void (_ns::_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< \
  &_ns::_concept <_type_var1,_type_var2,_type_var3,_type_var4>::__constraints> \
    _concept_checking_typedef##_type_var1##_type_var2##_type_var3##_type_var4##_concept


template <class _Tp1, class _Tp2>
struct _Aux_require_same { };

template <class _Tp>
struct _Aux_require_same<_Tp,_Tp> { typedef _Tp _Type; };

  template <class _Tp1, class _Tp2>
  struct _SameTypeConcept
  {
    void __constraints() {
      typedef typename _Aux_require_same<_Tp1, _Tp2>::_Type _Required;
    }
  };

  template <class _Tp>
  struct _IntegerConcept {
    void __constraints() { 
      __error_type_must_be_an_integer_type();
    }
  };
  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() {} };
  template <> struct _IntegerConcept<long long> { void __constraints() {} };
  template <> struct _IntegerConcept<unsigned long long>
                                                { void __constraints() {} };

  template <class _Tp>
  struct _SignedIntegerConcept {
    void __constraints() { 
      __error_type_must_be_a_signed_integer_type();
    }
  };
  template <> struct _SignedIntegerConcept<short> { void __constraints() {} };
  template <> struct _SignedIntegerConcept<int> { void __constraints() {} };
  template <> struct _SignedIntegerConcept<long> { void __constraints() {} };
  template <> struct _SignedIntegerConcept<long long> { void __constraints(){}};

  template <class _Tp>
  struct _UnsignedIntegerConcept {
    void __constraints() { 
      __error_type_must_be_an_unsigned_integer_type();
    }
  };
  template <> struct _UnsignedIntegerConcept<unsigned short>
    { void __constraints() {} };
  template <> struct _UnsignedIntegerConcept<unsigned int>
    { void __constraints() {} };
  template <> struct _UnsignedIntegerConcept<unsigned long>
    { void __constraints() {} };
  template <> struct _UnsignedIntegerConcept<unsigned long long>
    { void __constraints() {} };

  //===========================================================================
  // Basic Concepts

  template <class _Tp>
  struct _DefaultConstructibleConcept
  {
    void __constraints() {
      _Tp __a _IsUnused;                // require default constructor
    }
  };

  template <class _Tp>
  struct _AssignableConcept
  {
    void __constraints() {
      __a = __a;                        // require assignment operator
      __const_constraints(__a);
    }
    void __const_constraints(const _Tp& __b) {
      __a = __b;                   // const required for argument to assignment
    }
    _Tp __a;
    // possibly should be "Tp* a;" and then dereference "a" in constraint
    // functions?  present way would require a default ctor, i think...
  };

  template <class _Tp>
  struct _CopyConstructibleConcept
  {
    void __constraints() {
      _Tp __a(__b);                     // require copy constructor
      _Tp* __ptr _IsUnused = &__a;      // require address of operator
      __const_constraints(__a);
    }
    void __const_constraints(const _Tp& __a) {
      _Tp __c(__a) _IsUnused;           // require const copy constructor
      const _Tp* __ptr _IsUnused = &__a; // require const address of operator
    }
    _Tp __b;
  };

  // The SGI STL version of Assignable requires copy constructor and operator=
  template <class _Tp>
  struct _SGIAssignableConcept
  {
    void __constraints() {
      _Tp __b(__a) _IsUnused;
      __a = __a;                        // require assignment operator
      __const_constraints(__a);
    }
    void __const_constraints(const _Tp& __b) {
      _Tp __c(__b) _IsUnused;
      __a = __b;              // const required for argument to assignment
    }
    _Tp __a;
  };

  template <class _From, class _To>
  struct _ConvertibleConcept
  {
    void __constraints() {
      _To __y _IsUnused = __x;
    }
    _From __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 _Tp>
  void __aux_require_boolean_expr(const _Tp& __t) {
    bool __x _IsUnused = __t;
  }

// FIXME
  template <class _Tp>
  struct _EqualityComparableConcept
  {
    void __constraints() {
      __aux_require_boolean_expr(__a == __b);
      __aux_require_boolean_expr(__a != __b);
    }
    _Tp __a, __b;
  };

  template <class _Tp>
  struct _LessThanComparableConcept
  {
    void __constraints() {
      __aux_require_boolean_expr(__a < __b);
    }
    _Tp __a, __b;
  };

  // This is equivalent to SGI STL's LessThanComparable.
  template <class _Tp>
  struct _ComparableConcept
  {
    void __constraints() {
      __aux_require_boolean_expr(__a < __b);
      __aux_require_boolean_expr(__a > __b);
      __aux_require_boolean_expr(__a <= __b);
      __aux_require_boolean_expr(__a >= __b);
    }
    _Tp __a, __b;
  };

#define _GLIBCPP_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 _GLIBCPP_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; \
  }

  _GLIBCPP_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(==, _EqualOpConcept);
  _GLIBCPP_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(!=, _NotEqualOpConcept);
  _GLIBCPP_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(<, _LessThanOpConcept);
  _GLIBCPP_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(<=, _LessEqualOpConcept);
  _GLIBCPP_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(>, _GreaterThanOpConcept);
  _GLIBCPP_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT(>=, _GreaterEqualOpConcept);

  _GLIBCPP_DEFINE_BINARY_OPERATOR_CONSTRAINT(+, _PlusOpConcept);
  _GLIBCPP_DEFINE_BINARY_OPERATOR_CONSTRAINT(*, _TimesOpConcept);
  _GLIBCPP_DEFINE_BINARY_OPERATOR_CONSTRAINT(/, _DivideOpConcept);
  _GLIBCPP_DEFINE_BINARY_OPERATOR_CONSTRAINT(-, _SubtractOpConcept);
  _GLIBCPP_DEFINE_BINARY_OPERATOR_CONSTRAINT(%, _ModOpConcept);

#undef _GLIBCPP_DEFINE_BINARY_PREDICATE_OP_CONSTRAINT
#undef _GLIBCPP_DEFINE_BINARY_OPERATOR_CONSTRAINT

  //===========================================================================
  // Function Object Concepts

  template <class _Func, class _Return>
  struct _GeneratorConcept
  {
    void __constraints() {
      const _Return& __r _IsUnused = __f();// require operator() member function
    }
    _Func __f;
  };


  template <class _Func>
  struct _GeneratorConcept<_Func,void>
  {
    void __constraints() {
      __f();                            // require operator() member function
    }
    _Func __f;
  };

  template <class _Func, class _Return, class _Arg>
  struct _UnaryFunctionConcept
  {
    void __constraints() {
      __r = __f(__arg);                  // require operator()
    }
    _Func __f;
    _Arg __arg;
    _Return __r;
  };

  template <class _Func, class _Arg>
  struct _UnaryFunctionConcept<_Func, void, _Arg> {
    void __constraints() { 
      __f(__arg);                       // require operator()
    }
    _Func __f;
    _Arg __arg;
  };

  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;
  };

  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;
  };

  template <class _Func, class _Arg>
  struct _UnaryPredicateConcept
  {
    void __constraints() {
      __aux_require_boolean_expr(__f(__arg)); // require op() returning bool
    }
    _Func __f;
    _Arg __arg;
  };

  template <class _Func, class _First, class _Second>
  struct _BinaryPredicateConcept
  {
    void __constraints() {
      __aux_require_boolean_expr(__f(__a, __b)); // require op() 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
      __aux_require_boolean_expr(__fun(__a, __b));
    }
    _Func __f;
    _First __a;
    _Second __b;
  };

  //===========================================================================
  // Iterator Concepts

  template <class _Tp>
  struct _TrivialIteratorConcept
  {
    void __constraints() {
      __function_requires< _DefaultConstructibleConcept<_Tp> >();
      __function_requires< _AssignableConcept<_Tp> >();
      __function_requires< _EqualityComparableConcept<_Tp> >();
//      typedef typename std::iterator_traits<_Tp>::value_type _V;
      (void)*__i;                       // require dereference operator
    }
    _Tp __i;
  };

  template <class _Tp>
  struct _Mutable_TrivialIteratorConcept
  {
    void __constraints() {
      __function_requires< _TrivialIteratorConcept<_Tp> >();
      *__i = *__j;                      // require dereference and assignment
    }
    _Tp __i, __j;
  };

  template <class _Tp>
  struct _InputIteratorConcept
  {
    void __constraints() {
      __function_requires< _TrivialIteratorConcept<_Tp> >();
      // require iterator_traits typedef's
      typedef typename std::iterator_traits<_Tp>::difference_type _D;
//      __function_requires< _SignedIntegerConcept<_D> >();
      typedef typename std::iterator_traits<_Tp>::reference _R;
      typedef typename std::iterator_traits<_Tp>::pointer _Pt;
      typedef typename std::iterator_traits<_Tp>::iterator_category _Cat;
      __function_requires< _ConvertibleConcept<
        typename std::iterator_traits<_Tp>::iterator_category,
        std::input_iterator_tag> >();
      ++__i;                            // require preincrement operator
      __i++;                            // require postincrement operator
    }
    _Tp __i;
  };

  template <class _Tp, class _ValueT>
  struct _OutputIteratorConcept
  {
    void __constraints() {
      __function_requires< _AssignableConcept<_Tp> >();
      ++__i;                            // require preincrement operator
      __i++;                            // require postincrement operator
      *__i++ = __t;                     // require postincrement and assignment
    }
    _Tp __i;
    _ValueT __t;
  };

  template <class _Tp>
  struct _ForwardIteratorConcept
  {
    void __constraints() {
      __function_requires< _InputIteratorConcept<_Tp> >();
      __function_requires< _ConvertibleConcept<
        typename std::iterator_traits<_Tp>::iterator_category,
        std::forward_iterator_tag> >();
      typedef typename std::iterator_traits<_Tp>::reference _R;
      _R __r _IsUnused = *__i;