c++ - wstring null 终止了吗？

Question

std::wstring 的内部结构是什么？包括长度吗？它是空终止的吗？两个？

Answer 1

Does it include the length

是的。它是 C++11 标准所要求的。

§ 21.4.4

size_type size() const noexcept;
1. Returns: A count of the number of char-like objects currently in the string.
2. Complexity: constant time.

但是请注意，这是无法识别 unicode 的。

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Is it null terminated

是的。 C++11 标准还要求 std::basic_string::c_str 返回 [0,size()] 范围内的有效指针，其中 my_string[my_string.size ()] 将是有效的，因此是一个空字符。

§ 21.4.7.1

const charT* c_str() const noexcept;
const charT* data() const noexcept;
1. Returns: A pointer p such that p + i == &operator[](i) for each i in [0,size()].
2. Complexity: constant time.
3. Requires: The program shall not alter any of the values stored in the character array.