如何构造一个带有嵌入式null的std :: string？ [英] How do you construct a std::string with an embedded null?

问题描述

如果我想构造一个带有如下行的std :: string：

  std :: string my_string \0b）; 
  

我想在结果字符串（a，null，b）中有三个字符，得到一个。正确的语法是什么？

解决方案

问题是 std :: string 构造函数，它接受一个 const char * 假设输入是一个C字符串。 C字符串 \0 终止，因此解析在到达 \0 字符时停止。

为了弥补这一点，您需要使用从char数组（而不是C-String）构建字符串的构造函数。这需要两个参数 - 指向数组的指针和长度：

  std :: string x（pq \0rs ）; //两个字符，因为输入假设为C-String 
 std :: string x（pq\0rs，5）; // 5字符作为输入现在是一个有5个字符的字符数组。 
  

注意：C ++ std :: string NOT \0 - 已终止（如其他帖子中所建议）。但是，您可以使用方法 c_str（）提取包含C字符串的内部缓冲区的指针。

另请参阅 Doug T的回答

a>

If I want to construct a std::string with a line like:

std::string my_string("a\0b");

Where i want to have three characters in the resulting string (a, null, b), I only get one. What is the proper syntax?

解决方案

The problem is the std::string constructor that takes a const char* assumes the input is a C-string. C-strings are \0 terminated and thus parsing stops when it reaches the \0 character.

To compensate for this, you need to use the constructor that builds the string from a char array (not a C-String). This takes two parameters - a pointer to the array and a length:

std::string   x("pq\0rs");   // Two characters because input assumed to be C-String
std::string   x("pq\0rs",5); // 5 Characters as the input is now a char array with 5 characters.

Note: C++ std::string is NOT \0-terminated (as suggested in other posts). However, you can extract a pointer to an internal buffer that contains a C-String with the method c_str().

Also check out Doug T's answer below about using a vector<char>.

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