C++ 概念： BitmaskType
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定义了一种类型，它可以被用来表示一组常数值或这些值的任何组合。这种特质的典型实现是整数类型，std::bitset，或枚举（范围和无作用域）额外的运算符重载.
原文：
Defines a type that can be used to represent a set of constant values or any combination of those values. This trait is typically implemented by integer types, std::bitset, or enumerations (scoped and unscoped) with additional operator overloads.
[编辑] 要求
的位掩码类型支持有限数量的位掩码的元素，这是不同的值的位掩码类型，例如，对于任何一对Ci和Cj，Ci & Ci != 0和Ci & Cj == 0.
原文：
The bitmask type supports a finite number of bitmask elements, which are distinct values of the bitmask type, such that, for any pair Ci and Cj, Ci & Ci != 0 and Ci & Cj == 0.
按位运算符operator&，operator|，operator^，operator~，operator&=，operator|=，并operator^=定义的位掩码类型的值，并有相应的内置运营商无符号整数相同的语义，如果是不同的整数位掩码元素两个权力.
原文：
The bitwise operators operator&, operator|, operator^, operator~, operator&=, operator|=, and operator^= are defined for values of the bitmask type and have the same semantics as the corresponding built-in operators on unsigned integers would have if the bitmask elements were the distinct integer powers of two.
下面的表达式是良好的，任何BitsetType十
原文：
The following expressions are well-formed and have the following meaning for any BitsetType X
| X |= Y | 设置对象的X值Y
|
| X &= ~Y | 清除对象的X值Y
|
| X&Y != 0 | 表示的值Y被设置在对象的X
原文： indicates that the value Y is set in the object X |
具有以下涵义。
的每个representible位掩码元素被定义作为constexpr位掩码类型值.
原文：
Each representible bitmask element is defined as a constexpr value of the bitmask type.
[编辑] 用法
以下的标准库，能满足不同
BitmaskType原文：
The following standard library types satisfy
BitmaskType:- std::ctype_base::mask
- std::ios_base::fmtflags
- std::ios_base::iostate
- std::ios_base::openmode
- std::regex_traits::char_class_type
- std::regex_constants::syntax_option_type
- std::regex_constants::match_flag_type
- std::launch,
依赖于一些特定的实施方案（例如int n = std::ios_base::hex），代码是不可移植的，因为std::ios_base::fmtflags不一定是隐式转换为int.
原文：
Code that relies on some particular implementation option (e.g. int n = std::ios_base::hex), is nonportable because std::ios_base::fmtflags is not necessarily implicitly convertible to int.
