问题描述
在 array ， string 和 vector 全部得到了 data 方法，该方法为：
In c++11 array, string, and vector all got the data method which:
此方法以可变的 const 版本提供，适用于所有适用的容器，例如：
This method is provided in a mutable and const version for all applicable containers, for example:
T* vector<T>::data();
const T* vector<T>::data() const;
所有适用的容器，即 string ：
All applicable containers, that is, except string which only provides the const version:
const char* string::data() const;
这里发生了什么？为什么 string 变短了，而 char * string :: data（）会如此有用？
What happened here? Why did string get shortchanged, when char* string::data() would be so helpful?
推荐答案
简短的答案是确实提供了。对于类似的 ，这样就可以对底层C字符串进行可变访问：
The short answer is that c++17 does provide the char* string::data() method. Which is vital for the similarly c++17 data function, thus to gain mutable access to the underlying C-String I can now do this:
auto foo = "lorem ipsum"s;
for(auto i = data(foo); *i != '\0'; ++i) ++(*i);
出于历史目的，值得编年表 string 的发展，其中建立在以下基础上：在对 string 的基础缓冲区的访问因其元素的新要求而成为可能连续存储，这样对于任何给定的 string s ：
For historical purposes it's worth chronicling string's development which c++17 is building upon: In c++11 access to string's underlying buffer is made possible possible by a new requirement that it's elements are stored contiguously such that for any given string s:
可以通过v获得对该新要求的基础C字符串的可变访问各种方法，例如：& s.front（），& s [0] 或& * s.first（）但是回到最初的问题，它将避免使用以下选项之一的负担：为什么无法访问 string 的基础缓冲区是以 char * string :: data（）？
Mutable access to this newly required underlying C-String was obtainable by various methods, for example: &s.front(), &s[0], or &*s.first() But back to the original question which would avoid the burden of using one of these options: Why hasn't access to string's underlying buffer been provided in the form of char* string::data()?
要回答这一点，必须注意： T * array< T> :: data（）和 T * vector< T> :: data（）是的问题。 是。在此之前已经存在。尽管不明确保证要指向任何底层缓冲区，但这是从<$ c中获得 const char * 的唯一方法$ c> string
To answer that it is important to note that T* array<T>::data() and T* vector<T>::data() were an addition required by c++11. No additional requirements were incurred by c++11 against other contiguous containers such as deque. And there certainly wasn't an additional requirement for string, in fact the requirement that string was contiguous was new to c++11. Before this const char* string::data() had existed. Though it explicitly was not guaranteed to be pointing to any underlying buffer, it was the only way to obtain a const char* from a string:
这意味着 string 并未变短 agged / c％2b％2b11 class = post-tag title =显示已标记'c ++ 11'的问题 rel = tag> c ++ 11 过渡到 data 访问器，因此根本不包括它，因此只有 const data 访问者先前拥有的 string 仍然存在。在C ++ 11的实现中，有，这需要直接写入字符串的基础缓冲区。
This means that string was not "shortchanged" in c++11's transition to data accessors, it simply was not included thus only the const data accesor that string previously possessed persisted. There are naturally occurring examples in C++11's implementation which necessitate writing directly to the underlying buffer of a string.
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