c++ - 通过空行 boost 分割字符串

Question

有没有办法在遇到空行时使用 boost::split 来分割字符串？

这是我的意思的一个片段。

std::stringstream source;
source.str(input_string);
std::string line;
std::getline(source, line, '\0');
std::vector<std::string> token;
boost:split(token,line, boost::is_any_of("what goes here for blank line");

Answer 1

您可以按双 \n\n 分割，除非您将空行表示为“可能包含其他空白的行”。

<强> Live On Coliru

#include <boost/regex.hpp>
#include <boost/algorithm/string_regex.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <sstream>
#include <iostream>
#include <iomanip>

int main() {
    std::stringstream source;
    source.str(R"(line one

that was an empty line, now some whitespace:
      
bye)");

    std::string line(std::istreambuf_iterator<char>(source), {});
    std::vector<std::string> tokens;

    auto re = boost::regex("\n\n");
    boost::split_regex(tokens, line, re);

    for (auto token : tokens) {
        std::cout << std::quoted(token) << "\n";
    }
}

打印

"line one"
"that was an empty line, now some whitespace:
      
bye"

在“空”行上允许有空格

用正则表达式表达即可:

auto re = boost::regex(R"(\n\s*\n)");

现在输出是: Live On Coliru

"line one"
"that was an empty line, now some whitespace:"
"bye"