std::ctype<char>::is
STD：：Ctype<char>*IS
| Defined in header | | |
|---|---|---|
| bool is(mask m, char c) const; | (1) | |
| const char* is(const char* low, const char* high, mask* vec) const; | (2) | |
1%29检查字符是否c按面具分类m根据成员函数返回的分类表table().有效地计算table()[(unsigned char)c] & m
2%29对字符数组中的每个字符[low, high)，从成员函数返回的分类表中读取其完整的分类掩码。table()%28，即，评估table()[ (unsigned char)*p]并将其存储在vec
如果(unsignedchar)c >=std::ctype<char>::table_size，则替换一个实现定义的值，而不是table()[(unsigned char)c]的值不同，可能会有所不同。c...
参数
| c | - | character to classify |
|---|---|---|
| m | - | mask to use for classifying a single character |
| low | - | pointer to the first character in an array of characters to classify |
| high | - | one past the end pointer for the array of characters to classify |
| vec | - | pointer to the first element of the array of masks to fill |
返回值
1%29true如果c按m在table()
2%29high
注记
与主模板不同std::ctype，此专门化在对字符进行分类时不执行虚拟函数调用。要自定义行为，派生类可以向基类构造函数提供非默认的分类表。
例
另见
| do_is virtual | classifies a character or a character sequence (virtual protected member function of std::ctype) |
|---|
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