std::basic_string_view::compare
性病：基本[医]弦[医]意见：：比较
| constexpr int compare(basic_string_view v) const; | (1) | (since C++17) |
|---|---|---|
| constexpr int compare(size_type pos1, size_type count1, basic_string_view v) const; | (2) | (since C++17) |
| constexpr int compare(size_type pos1, size_type count1, basic_string_view v, size_type pos2, size_type count2) const; | (3) | (since C++17) |
| constexpr int compare(const CharT* s) const; | (4) | (since C++17) |
| constexpr int compare(size_type pos1, size_type count1, const CharT* s) const; | (5) | (since C++17) |
| constexpr int compare(size_type pos1, size_type count1, const CharT* s, size_type count2) const; | (6) | (since C++17) |
比较两个字符序列。
1%29长度rlen要比较的序列中，较小的size()和v.size()函数通过调用traits::compare(data(), v.data(), rlen)，并根据下表返回一个值：
| Condition | Result | Return value |
|---|---|---|
| Traits::compare(data(), v.data(), rlen) < 0 | this is less than v | <0 |
| Traits::compare(data(), v.data(), rlen) == 0 | size() < v.size() | this is less than v |
| size() == v.size() | this is equal to v | 0 |
| size() > v.size() | this is greater than v | 0 |
| Traits::compare(data(), v.data(), rlen) > 0 | this is greater than v | 0 |
2%29相当于substr(pos1, count1).compare(v)...
3%29相当于substr(pos1, count1).compare(v.substr(pos2, count2))...
4%29相当于compare(basic_string_view(s))...
5%29相当于substr(pos1, count1).compare(basic_string_view(s))...
6%29相当于substr(pos1, count1).compare(basic_string_view(s, count2))...
参数
| v | - | view to compare |
|---|---|---|
| s | - | pointer to the character string to compare to |
| count1 | - | number of characters of this view to compare |
| pos1 | - | position of the first character in this view to compare |
| count2 | - | number of characters of the given view to compare |
| pos2 | - | position of the first character of the given view to compare |
返回值
如果此视图小于其他字符序列，则为负值；如果两个字符序列相等，则为零；如果此视图大于其他字符序列，则为正值。
例外
1%29
noexcept规格：
noexcept
复杂性
1%~29线性在字符数比较。
另见
| operator==operator!=operator | lexicographically compares two string views (function template) |
|---|
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