std::binary_negate
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< cpp | utility | functional
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在头文件 <functional> 中定义
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template< class Predicate > struct binary_negate : |
(至 C++11) | |
template< class Predicate > struct binary_negate; |
(C++11 起) | |
binary_negate
是一个包装函数对象返回其持有的二元谓词的补.原文:
binary_negate
is a wrapper function object returning the complement of the binary predicate it holds.二元谓词类型必须定义两个的成员类型
first_argument_type
和second_argument_type
,可转换谓词的参数类型。从std::owner_less的函数对象,std::ref,std::cref,std::plus,std::minus,std::multiplies,std::divides,std::modulus,std::equal_to,std::not_equal_to,std::greater,std::less,std::greater_equal,std::less_equal,std::logical_not,std::logical_or,std::bit_and,std::bit_or,std::bit_xor,std::mem_fn,std::map::value_comp,std::multimap::value_comp,std::function ,或调用std::not2这些定义的类型,函数对象来自过时的std::binary_function. 原文:
The binary predicate type must define two member types,
first_argument_type
and second_argument_type
, that are convertible to the predicate's parameter types. The function objects obtained from std::owner_less, std::ref, std::cref, std::plus, std::minus, std::multiplies, std::divides, std::modulus, std::equal_to, std::not_equal_to, std::greater, std::less, std::greater_equal, std::less_equal, std::logical_not, std::logical_or, std::bit_and, std::bit_or, std::bit_xor, std::mem_fn, std::map::value_comp, std::multimap::value_comp, std::function, or from a call to std::not2 have these types defined, as are function objects derived from the deprecated std::binary_function. binary_negate
对象很容易构造辅助函数std::not2.原文:
binary_negate
objects are easily constructed with helper function std::not2.目录 |
[编辑] 会员类型
类型
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Definition |
first_argument_type
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Predicate::first_argument_type |
second_argument_type
|
Predicate::second_argument_type |
result_type
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bool |
[编辑] 成员函数
(constructor) |
constructs a new binary_negate object with the supplied predicate (公共成员函数) |
operator() |
返回的逻辑补码的呼叫的结果,所存储的谓词 原文: returns the logical complement of the result of a call to the stored predicate (公共成员函数) |
的std :: binary_negate ::binary_negate
explicit binary_negate( Predicate const& pred ); |
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Constructs a binary_negate
function object with the stored predicate pred
.
Parameters
pred | - | 谓词函数对象
|
的std :: binary_negate ::operator()
bool operator()( first_argument_type const& x, second_argument_type const& y ) const; |
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Returns the logical complement of the result of calling pred(x, y).
Parameters
x | - | 第一个参数传递到谓词
原文: first argument to pass through to predicate |
y | - | 第二个参数传递到谓词
原文: second argument to pass through to predicate |
Return value
The logical complement of the result of calling pred(x, y).
[编辑] 示例
#include <algorithm> #include <functional> #include <iostream> #include <vector> struct same : std::binary_function<int, int, bool> { bool operator()(int a, int b) const { return a == b; } }; int main() { std::vector<int> v1; std::vector<int> v2; for (int i = 0; i < 10; ++i) v1.push_back(i); for (int i = 0; i < 10; ++i) v2.push_back(10 - i); std::vector<bool> v3(v1.size()); std::binary_negate<same> not_same((same())); std::transform(v1.begin(), v1.end(), v2.begin(), v3.begin(), not_same); /* C++11 solution: // Use std::function<bool (int, int)> std::function<bool (int, int)> not_same = [](int x, int y)->bool{ return !same()(x, y); }; std::transform(v1.begin(), v1.end(), v2.begin(), v3.begin(), not_same); */ std::cout.setf(std::ios_base::boolalpha); for (int i = 0; i < 10; ++i) std::cout << v1[i] << ' ' << v2[i] << ' ' << v3[i] << '\n'; }
输出:
0 10 true 1 9 true 2 8 true 3 7 true 4 6 true 5 5 false 6 4 true 7 3 true 8 2 true 9 1 true
[编辑] 另请参阅
(已弃用) |
适配器兼容的二元函数的基类 原文: adaptor-compatible binary function base class (类模板) |
(C++11) |
包装任何类型的可调用对象与指定的函数调用签名 原文: wraps callable object of any type with specified function call signature (类模板) |
构造自定义std::binary_negate对象 原文: constructs custom std::binary_negate object (函数模板) | |
(已弃用) |
创建适配器兼容功能的包装对象从一个指针到函数 原文: creates an adaptor-compatible function object wrapper from a pointer to function (函数模板) |
包装函数对象返回的补一元谓词其持有的 原文: wrapper function object returning the complement of the unary predicate it holds (类模板) |