boost分割用单个字符或只是一个字符串 [英] boost split with a single character or just one string

问题描述

我希望在单个字符或字符串上拆分字符串。我想使用 boost :: split ，因为boost字符串是我们的基本字符串处理的标准（我不想混合几种技术）。

在单个字符的情况下，我可以做 split（vec，str，is_any_of（'：'））但我想知道如果有一种方法只指定一个字符。它可以提高性能，但更重要的是，我认为代码将更清晰只用一个字符，因为 is_any_of 传达一个不同的意思，我想要的。

为了匹配字符串，我不知道使用什么语法。我不想构造一个正则表达式;一些简单的语法如 split（vec，str，match_str（::）将是好的。

在下面的代码中，为了简洁，让我假设使用命名空间boost 。

对于分割字符，如果只允许 algorithm / string ，
is_from_range 可能用于：

  split（vec，str，is_from_range（'：'，'：'））; 
  

或者，如果允许 lambda ：

  split（vec，str，lambda :: _ 1 =='：'）; 
  

或如果准备专用谓词是允许的：

  struct match_char {
 char c; 
 match_char（char c）：c（c）{} 
 bool operator（）（char x）const {return x == c;} 
}; 
 
 split （vec，str，match_char（'：'））; 
  

提到，
似乎没有办法用 split 。
如果允许 iter_split ，以下代码可能符合目的：

  iter_split（vec，str，first_finder（::））; 
  

I wish to split a string on a single character or a string. I would like to use boost::split since boost string is our standard for basic string handling (I don't wish to mix several techniques).

In the single character case I could do split(vec,str,is_any_of(':')) but I'd like to know if there is a way to specify just a single character. It may improve performance, but more importantly I think the code would be clearer with just a single character, since is_any_of conveys a different meaning that what I want.

For matching against a string I don't know what syntax to use. I don't wish to to construct a regex; some simple syntax like split(vec,str,match_str("::") would be good.

解决方案

In the following code, let me assume using namespace boost for brevity.
As for splitting on a character, if only algorithm/string is allowed, is_from_range might serve the purpose:

split(vec,str, is_from_range(':',':'));

Alternatively, if lambda is allowed:

split(vec,str, lambda::_1 == ':');

or if preparing a dedicated predicate is allowed:

struct match_char {
  char c;
  match_char(char c) : c(c) {}
  bool operator()(char x) const { return x == c; }
};

split(vec,str, match_char(':'));

As for matching against a string, as David Rodri'guez mentioned, there seems not to be the way with split. If iter_split is allowed, probably the following code will meet the purpose:

iter_split(vec,str, first_finder("::"));

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