希望很多同学不是因为看到标题,出于好奇心才进来的. 以前我驻扎在CSDN一段时间,但是后来搬到了博客园. 博客园同CSDN比起来,感觉好很多,自己也不知道
是什么原因. 可能是CSDN现在很多所谓的技术专家都开始转行写小说了,俺不喜欢看小说,喜欢搞技术,所以就到了博客园.
标题上写着是介绍STL中的Concepts Check,可以说是一种机制. 今天我也是在阅读SGI STL源码的过程中遇到这个问题,问了很多人,也查阅了很多资料.但是很
多人表示对此毫不知情~ 下午又去图书馆找资料,最后也只是找到一本<<C++模板元编程>>,粗略的浏览了一下相关章节,有点吃力,原因是它的线索是前后贯穿的,引
用前面章节的例子来说明后面的概念,对于我这种不是很喜欢把一本书从头到尾仔细阅读的少年来说,真的是不方便,麻烦很多.感觉是这样子,我只是为了查找自己想要的
知识点,却要被迫去接受其他的章节知识,这种感觉真不爽~
另外也找到了关于SGI STL Concepts Check的相关介绍文档,可惜都是全英文的.我花了点时间粗略浏览了一下,表示压力很大.收获很小~
也只能结合SGI STL中的相关源码来说明一下Concepts Check这东西是个什么样子的,因为看得到. 要是详细的解释它,可能现在我还做不到.给我时间,相信可以做
到~
1.SGI STL中的Concepts.
// 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 ------ concept_checks.h // This file covers the following concepts: // _Sequence // _FrontInsertionSequence // _BackInsertionSequence ------ sequence_concepts.h
请原谅我的直白,我很直接的就给出了这些Concepts.也许你不知道这些是做什么的.不急,下面会解释的.
2. 随便打开一个类的实现: stl_stack.h
template <class _Tp, class _Sequence>
class stack {
// requirements:
__STL_CLASS_REQUIRES(_Tp, _Assignable); //1
__STL_CLASS_REQUIRES(_Sequence, _BackInsertionSequence); //2
typedef typename _Sequence::value_type _Sequence_value_type;
__STL_CLASS_REQUIRES_SAME_TYPE(_Tp, _Sequence_value_type); //3
//.....
如上面的源码,对后面标注数字的代码我比较感兴趣,从这些宏的名字来看,这些是检测用的宏.(这不算望文生义吧~)
3. 随便选择一个看看呗: 就__STL_CLASS_REQUIRES_SAME_TYPE吧,其他的也都一样.
它的源码很容易找到,在windows下面可以使用Source Insight,Notepad++这样的工具在工程中查找,在Linux下面也可以使用Emacs+cscope查找,很简单的,不多说.
源码如下,先不给出解释,然后慢慢分析:
#define __STL_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
看到这么长的宏,头大吗？ 莫着急,也不要害怕,一点点分析就是了.下面给出注释:(我自己分析的,没有参考其他资料,有错欢迎拍砖~)
#define __STL_CLASS_REQUIRES_SAME_TYPE(__type_x, __type_y) \
typedef void (* __func_##__type_x##__type_y##same_type)( __type_x, \
__type_y ); \ // __func_##__type_x##__type_y##same_type展开为函数指针类型. <1>
template < __func_##__type_x##__type_y##same_type _Tp1> \
struct __dummy_struct_##__type_x##__type_y##_same_type { }; \ // 定义一个傀儡结构体,为什么叫傀儡呢? dummy的中文意思就是傀儡,还有就是
// 这个结构体只是个空架子.什么都没有. 但是它是由作用的 <2>
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 // 利用上面的傀儡结构模板声明一个静态对象. <3>
在傀儡模板中使用_STL_SAME_TYPE_ERROR<__type_x, __type_y>::__type_X_not_same_as_type_Y这样一个模板成员函数.下面来看看这个函数:
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>();
}
};
这是个静态模板成员函数.__check_equal又是什么呢？ 我们继续~
template <class _Type> struct __check_equal { };
感觉这个是不是和傀儡模板结构差不多? 不同的~ 就作用而言都是不同的.
通过__check_equal<_TypeX> t1 = __check_equal<_TypeY>()来检查_TypeX和_TypeY是不是同种类型.
4. 到这里,虽然我们还不知道具体的原理,但是至少知道对于这个宏的理解不是望文生义了~
其实,检验是通过编译期检查的,该宏的作用是在编译器对类型进行检查,如果不相同就会抛出错误.只是编译期的开销,而在运行的时候完全没有开销~
5.扩展一下:仔细看一下concept_checks.h和sequence_concepts.h文件中,会发现大量的宏和傀儡模板结构.这都是为了实现Concepts Check.
/*
* 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 __STL_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 __STL_REQUIRES(__type_var, __concept) do {} while(0)
#define __STL_CLASS_REQUIRES(__type_var, __concept) \
static int __##__type_var##_##__concept
#define __STL_CONVERTIBLE(__type_x, __type_y) do {} while(0)
#define __STL_REQUIRES_SAME_TYPE(__type_x, __type_y) do {} while(0)
#define __STL_CLASS_REQUIRES_SAME_TYPE(__type_x, __type_y) \
static int __##__type_x##__type_y##_require_same_type
#define __STL_GENERATOR_CHECK(__func, __ret) do {} while(0)
#define __STL_CLASS_GENERATOR_CHECK(__func, __ret) \
static int __##__func##__ret##_generator_check
#define __STL_UNARY_FUNCTION_CHECK(__func, __ret, __arg) do {} while(0)
#define __STL_CLASS_UNARY_FUNCTION_CHECK(__func, __ret, __arg) \
static int __##__func##__ret##__arg##_unary_function_check
#define __STL_BINARY_FUNCTION_CHECK(__func, __ret, __first, __second) \
do {} while(0)
#define __STL_CLASS_BINARY_FUNCTION_CHECK(__func, __ret, __first, __second) \
static int __##__func##__ret##__first##__second##_binary_function_check
#define __STL_REQUIRES_BINARY_OP(__opname, __ret, __first, __second) \
do {} while(0)
#define __STL_CLASS_REQUIRES_BINARY_OP(__opname, __ret, __first, __second) \
static int __##__opname##__ret##__first##__second##_require_binary_op
#else /* __STL_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 __STL_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 __STL_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 __STL_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 __STL_GENERATOR_CHECK(__func, __ret) \
do { \
__ret (*__x)( __func&) = \
_STL_GENERATOR_ERROR< \
__func, __ret>::__generator_requirement_violation; \
__x = __x; } while (0)
#define __STL_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 __STL_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 __STL_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 __STL_NO_FUNCTION_PTR_IN_CLASS_TEMPLATE
#define __STL_CLASS_REQUIRES(__type_var, __concept)
#define __STL_CLASS_REQUIRES_SAME_TYPE(__type_x, __type_y)
#define __STL_CLASS_GENERATOR_CHECK(__func, __ret)
#define __STL_CLASS_UNARY_FUNCTION_CHECK(__func, __ret, __arg)
#define __STL_CLASS_BINARY_FUNCTION_CHECK(__func, __ret, __first, __second)
#define __STL_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 __STL_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 __STL_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 __STL_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 __STL_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 __STL_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 __STL_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 __STL_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; \
} \
}
__STL_DEFINE_BINARY_OP_CHECK(==, _OP_EQUAL);
__STL_DEFINE_BINARY_OP_CHECK(!=, _OP_NOT_EQUAL);
__STL_DEFINE_BINARY_OP_CHECK(<, _OP_LESS_THAN);
__STL_DEFINE_BINARY_OP_CHECK(<=, _OP_LESS_EQUAL);
__STL_DEFINE_BINARY_OP_CHECK(>, _OP_GREATER_THAN);
__STL_DEFINE_BINARY_OP_CHECK(>=, _OP_GREATER_EQUAL);
__STL_DEFINE_BINARY_OP_CHECK(+, _OP_PLUS);
__STL_DEFINE_BINARY_OP_CHECK(*, _OP_TIMES);
__STL_DEFINE_BINARY_OP_CHECK(/, _OP_DIVIDE);
__STL_DEFINE_BINARY_OP_CHECK(-, _OP_SUBTRACT);
__STL_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 */
__STL_BEGIN_NAMESPACE
template <class _Iterator> struct iterator_traits;
__STL_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) {
_STL_ERROR::__assignment_operator_requirement_violation(__a);
_STL_ERROR::__copy_constructor_requirement_violation(__a);
_STL_ERROR::__const_parameter_required_for_copy_constructor(__a,__a);
_STL_ERROR::__const_parameter_required_for_assignment_operator(__a,__a);
}
};
/* DefaultConstructible Requirements */
template <class _Type>
struct _DefaultConstructible_concept_specification {
static void _DefaultConstructible_requirement_violation(_Type __a) {
_STL_ERROR::__default_constructor_requirement_violation(__a);
}
};
/* EqualityComparable Requirements */
template <class _Type>
struct _EqualityComparable_concept_specification {
static void _EqualityComparable_requirement_violation(_Type __a) {
_STL_ERROR::__equality_comparable_requirement_violation(__a, __a);
}
};
/* LessThanComparable Requirements */
template <class _Type>
struct _LessThanComparable_concept_specification {
static void _LessThanComparable_requirement_violation(_Type __a) {
_STL_ERROR::__less_than_comparable_requirement_violation(__a, __a);
}
};
/* TrivialIterator Requirements */
template <class _TrivialIterator>
struct _TrivialIterator_concept_specification {
static void
_TrivialIterator_requirement_violation(_TrivialIterator __i) {
typedef typename
__value_type_type_definition_requirement_violation<_TrivialIterator>::
value_type __T;
// Refinement of Assignable
_Assignable_concept_specification<_TrivialIterator>::
_Assignable_requirement_violation(__i);
// Refinement of DefaultConstructible
_DefaultConstructible_concept_specification<_TrivialIterator>::
_DefaultConstructible_requirement_violation(__i);
// Refinement of EqualityComparable
_EqualityComparable_concept_specification<_TrivialIterator>::
_EqualityComparable_requirement_violation(__i);
// Valid Expressions
_STL_ERROR::__dereference_operator_requirement_violation(__i);
}
};
template <class _TrivialIterator>
struct _Mutable_TrivialIterator_concept_specification {
static void
_Mutable_TrivialIterator_requirement_violation(_TrivialIterator __i) {
_TrivialIterator_concept_specification<_TrivialIterator>::
_TrivialIterator_requirement_violation(__i);
// Valid Expressions
_STL_ERROR::__dereference_operator_and_assignment_requirement_violation(__i);
}
};
/* InputIterator Requirements */
template <class _InputIterator>
struct _InputIterator_concept_specification {
static void
_InputIterator_requirement_violation(_InputIterator __i) {
// Refinement of TrivialIterator
_TrivialIterator_concept_specification<_InputIterator>::
_TrivialIterator_requirement_violation(__i);
// Associated Types
__difference_type_type_definition_requirement_violation<_InputIterator>();
__reference_type_definition_requirement_violation<_InputIterator>();
__pointer_type_definition_requirement_violation<_InputIterator>();
__iterator_category_type_definition_requirement_violation<_InputIterator>();
// Valid Expressions
_STL_ERROR::__preincrement_operator_requirement_violation(__i);
_STL_ERROR::__postincrement_operator_requirement_violation(__i);
}
};
/* OutputIterator Requirements */
template <class _OutputIterator>
struct _OutputIterator_concept_specification {
static void
_OutputIterator_requirement_violation(_OutputIterator __i) {
// Refinement of Assignable
_Assignable_concept_specification<_OutputIterator>::
_Assignable_requirement_violation(__i);
// Associated Types
__iterator_category_type_definition_requirement_violation<_OutputIterator>();
// Valid Expressions
_STL_ERROR::__dereference_operator_requirement_violation(__i);
_STL_ERROR::__preincrement_operator_requirement_violation(__i);
_STL_ERROR::__postincrement_operator_requirement_violation(__i);
_STL_ERROR::
__postincrement_operator_and_assignment_requirement_violation(__i, *__i);
}
};
/* ForwardIterator Requirements */
template <class _ForwardIterator>
struct _ForwardIterator_concept_specification {
static void
_ForwardIterator_requirement_violation(_ForwardIterator __i) {
// Refinement of InputIterator
_InputIterator_concept_specification<_ForwardIterator>::
_InputIterator_requirement_violation(__i);
}
};
template <class _ForwardIterator>
struct _Mutable_ForwardIterator_concept_specification {
static void
_Mutable_ForwardIterator_requirement_violation(_ForwardIterator __i) {
_ForwardIterator_concept_specification<_ForwardIterator>::
_ForwardIterator_requirement_violation(__i);
// Refinement of OutputIterator
_OutputIterator_concept_specification<_ForwardIterator>::
_OutputIterator_requirement_violation(__i);
}
};
/* BidirectionalIterator Requirements */
template <class _BidirectionalIterator>
struct _BidirectionalIterator_concept_specification {
static void
_BidirectionalIterator_requirement_violation(_BidirectionalIterator __i) {
// Refinement of ForwardIterator
_ForwardIterator_concept_specification<_BidirectionalIterator>::
_ForwardIterator_requirement_violation(__i);
// Valid Expressions
_STL_ERROR::__predecrement_operator_requirement_violation(__i);
_STL_ERROR::__postdecrement_operator_requirement_violation(__i);
}
};
template <class _BidirectionalIterator>
struct _Mutable_BidirectionalIterator_concept_specification {
static void
_Mutable_BidirectionalIterator_requirement_violation(
_BidirectionalIterator __i)
{
_BidirectionalIterator_concept_specification<_BidirectionalIterator>::
_BidirectionalIterator_requirement_violation(__i);
// Refinement of mutable_ForwardIterator
_Mutable_ForwardIterator_concept_specification<_BidirectionalIterator>::
_Mutable_ForwardIterator_requirement_violation(__i);
typedef typename
__value_type_type_definition_requirement_violation<
_BidirectionalIterator>::value_type __T;
typename _Mutable_trait<__T>::_Type* __tmp_ptr = 0;
// Valid Expressions
_STL_ERROR::
__postincrement_operator_and_assignment_requirement_violation(__i,
*__tmp_ptr);
}
};
/* RandomAccessIterator Requirements */
template <class _RandAccIter>
struct _RandomAccessIterator_concept_specification {
static void
_RandomAccessIterator_requirement_violation(_RandAccIter __i) {
// Refinement of BidirectionalIterator
_BidirectionalIterator_concept_specification<_RandAccIter>::
_BidirectionalIterator_requirement_violation(__i);
// Refinement of LessThanComparable
_LessThanComparable_concept_specification<_RandAccIter>::
_LessThanComparable_requirement_violation(__i);
typedef typename
__value_type_type_definition_requirement_violation<_RandAccIter>
::value_type
value_type;
typedef typename
__difference_type_type_definition_requirement_violation<_RandAccIter>
::difference_type
_Dist;
typedef typename _Mutable_trait<_Dist>::_Type _MutDist;
// Valid Expressions
_STL_ERROR::__iterator_addition_assignment_requirement_violation(__i,
_MutDist());
_STL_ERROR::__iterator_addition_requirement_violation(__i,
_MutDist());
_STL_ERROR::
__iterator_subtraction_assignment_requirement_violation(__i,
_MutDist());
_STL_ERROR::__iterator_subtraction_requirement_violation(__i,
_MutDist());
_STL_ERROR::__difference_operator_requirement_violation(__i, __i,
_MutDist());
typename _Mutable_trait<value_type>::_Type* __dummy_ptr = 0;
_STL_ERROR::__element_access_operator_requirement_violation(__i,
__dummy_ptr,
_MutDist());
}
};
template <class _RandAccIter>
struct _Mutable_RandomAccessIterator_concept_specification {
static void
_Mutable_RandomAccessIterator_requirement_violation(_RandAccIter __i)
{
_RandomAccessIterator_concept_specification<_RandAccIter>::
_RandomAccessIterator_requirement_violation(__i);
// Refinement of mutable_BidirectionalIterator
_Mutable_BidirectionalIterator_concept_specification<_RandAccIter>::
_Mutable_BidirectionalIterator_requirement_violation(__i);
typedef typename
__value_type_type_definition_requirement_violation<_RandAccIter>
::value_type
value_type;
typedef typename
__difference_type_type_definition_requirement_violation<_RandAccIter>
::difference_type
_Dist;
typename _Mutable_trait<value_type>::_Type* __tmp_ptr = 0;
// Valid Expressions
_STL_ERROR::__element_assignment_operator_requirement_violation(__i,
__tmp_ptr, _Dist());
}
};
#define __STL_TYPEDEF_REQUIREMENT(__REQUIREMENT) \
template <class Type> \
struct __##__REQUIREMENT##__typedef_requirement_violation { \
typedef typename Type::__REQUIREMENT __REQUIREMENT; \
}
__STL_TYPEDEF_REQUIREMENT(value_type);
__STL_TYPEDEF_REQUIREMENT(difference_type);
__STL_TYPEDEF_REQUIREMENT(size_type);
__STL_TYPEDEF_REQUIREMENT(reference);
__STL_TYPEDEF_REQUIREMENT(const_reference);
__STL_TYPEDEF_REQUIREMENT(pointer);
__STL_TYPEDEF_REQUIREMENT(const_pointer);
template <class _Alloc>
struct _Allocator_concept_specification {
static void
_Allocator_requirement_violation(_Alloc __a) {
// Refinement of DefaultConstructible
_DefaultConstructible_concept_specification<_Alloc>::
_DefaultConstructible_requirement_violation(__a);
// Refinement of EqualityComparable
_EqualityComparable_concept_specification<_Alloc>::
_EqualityComparable_requirement_violation(__a);
// Associated Types
__value_type__typedef_requirement_violation<_Alloc>();
__difference_type__typedef_requirement_violation<_Alloc>();
__size_type__typedef_requirement_violation<_Alloc>();
__reference__typedef_requirement_violation<_Alloc>();
__const_reference__typedef_requirement_violation<_Alloc>();
__pointer__typedef_requirement_violation<_Alloc>();
__const_pointer__typedef_requirement_violation<_Alloc>();
typedef typename _Alloc::value_type _Tp;
//__STL_REQUIRES_SAME_TYPE(typename _Alloc::__STL_TEMPLATE rebind<_Tp>::other,
// _Alloc);
}
};
#endif /* __STL_USE_CONCEPT_CHECKS */
#endif /* __CONCEPT_CHECKS_H */
// Local Variables:
// mode:C++
// End:
上面贴了concept_checks.h源码,感兴趣的话可以看一下.
"可不可以 牵你的手呢 从来没有 这样要求" -- 陈升<<不再让你孤单>>