c++ strip

#include <cctype>
#include <vector>
#include <optional>
#include <string>
#include <stdexcept>
#include <fstream>

class Utils {
public:
    static bool endswith(const std::string &a, const std::string &b) {
        if (a.rfind(b) == (a.length() - b.length())) {
            return true;
        }

        return false;
    }

    static bool startswith(const std::string &a, const std::string &b) {
        if (a.compare(0, b.size(), b) == 0) {
            return true;
        }

        return false;
    }

    static std::vector<std::string> split(const std::string& s, const std::string delimiter=" ") {
        std::string cp = s;
        std::vector<std::string> vecStr;
        size_t pos = 0;
        std::string token;
        while ((pos = cp.find(delimiter)) != std::string::npos) {
            token = cp.substr(0, pos);
            vecStr.push_back(token);
            cp.erase(0, pos + delimiter.length());
        }
        vecStr.push_back(cp);
        return vecStr;
    }

    static std::string strip(const std::string &str,char ch=' ')
    {
        //除去str两端的ch字符
        int i = 0;
        while (str[i] == ch)// 头部ch字符个数是 i
            i++;
        int j = str.size() - 1;
        while (str[j] == ch ) //
            j--;        
        return str.substr(i, j+1 -i );
    }

    static std::string lstrip(const std::string &str, char ch)
    {
        //除去str两端的ch字符
        int i = 0;
        while (str[i] == ch)// 头部ch字符个数是 i
            i++;
        int j = str.size() - 1;
        return str.substr(i, j + 1 - i);
    }

    static std::string rstrip(const std::string &str, char ch)
    {
        //除去str两端的ch字符
        int i = 0;
        int j = str.size() - 1;
        while (str[j] == ch ) //
            j--;        
        return str.substr(i, j + 1 - i );
    }

    static std::string strip(const std::string &str)
    {
        //除去str两端的ch字符
        int i = 0;
        while (std::isspace(str[i]))// 头部ch字符个数是 i
            i++;
        int j = str.size() - 1;
        while (std::isspace(str[j])) //
            j--;        
        return str.substr(i, j+1 -i );
    }

    static std::string lstrip(const std::string &str)
    {
        //除去str两端的ch字符
        int i = 0;
        while (std::isspace(str[i]))// 头部ch字符个数是 i
            i++;
        int j = str.size() - 1;
        return str.substr(i, j + 1 - i);
    }

    static std::string rstrip(const std::string &str)
    {
        //除去str两端的ch字符
        int i = 0;
        int j = str.size() - 1;
        while (std::isspace(str[j])) //
            j--;        
        return str.substr(i, j + 1 - i );
    }

    static std::string read_file(const std::string &name) {
        std::ifstream ifs(name);
        std::string content( (std::istreambuf_iterator<char>(ifs) ),
                (std::istreambuf_iterator<char>()    ) );
        return content;
    }
};