c++: python_like code in c++. 在C++中以python的方式写部分代码

python_like.h

#ifndef __PYTHON_LIKE__
#define __PYTHON_LIKE__

#include <stdio.h>
#include <string>
#include <fstream>
#include <streambuf>
#include <vector>
#include <iostream>
#include <stdarg.h>
#include <assert.h>

namespace pyl {

// 超级无敌print
template <class T> void print(T v) { std::cout << v << std::endl; }
template <class T,class T2> void print(T v,T2 v2) { std::cout << v << " " << v2 << std::endl; }
template <class T,class T2,class T3> void print(T v,T2 v2,T3 v3) { std::cout << v << " " << v2 << " " << v3 << std::endl; }
template <class T,class T2,class T3,class T4> void print(T v,T2 v2,T3 v3,T4 v4) { std::cout << v << " " << v2 << " " << v3 << " " << v4 << std::endl; }
template <class T,class T2,class T3,class T4,class T5> void print(T v,T2 v2,T3 v3,T4 v4,T5 v5) { std::cout << v << " " << v2 << " " << v3 << " " << v4 << " " << v5 << std::endl; }
template <class T,class T2,class T3,class T4,class T5,class T6> void print(T v,T2 v2,T3 v3,T4 v4,T5 v5,T6 v6) { std::cout << v << " " << v2 << " " << v3 << " " << v4 << " " << v5 << " " << v6 << std::endl; }
template <class T,class T2,class T3,class T4,class T5,class T6,class T7> void print(T v,T2 v2,T3 v3,T4 v4,T5 v5,T6 v6,T7 v7) { std::cout << v << " " << v2 << " " << v3 << " " << v4 << " " << v5 << " " << v6 << " " << v7 << std::endl; }

/*
 * 格式化字符串，并返回为string形式
 * strf string_format
 */
std::string strf(const char *format, ...){
    static const int BUF_SIZE = 256;
    std::string ret;

    char buffer[BUF_SIZE];

    va_list args;

    // use vsnprintf to format 
    va_start(args, format);
    int n = vsnprintf(buffer, BUF_SIZE, format, args);
    va_end(args);

    if (n >= 0 && n < BUF_SIZE) {
        // ok
        ret = std::string(buffer);
    } else if (n >= BUF_SIZE) {
        // buffer not enough. try again.
        
        char *buf = new char[n+1];

        // format again
        va_start(args, format);
        int n2 = vsnprintf(buf, n+1, format, args);
        va_end(args);
        
        // they must be equal
        assert(n2 == n);

        delete buf;

        ret = std::string(buf);
    }

    return ret;
}

/*
 * 模仿 Python 的 str object
 */
class str: public std::string {
public:
    str(){}
    str(const char *s): std::string(s){}
    str(const std::string &s): std::string(s){}
    str(int v) {
        *this = strf("%d", v);
    }

    std::vector<str> split(char seg) {
        std::vector<str> res;
        const char *cstr = this->c_str();

        std::string s;

        int i = 0;
        int end = strlen(cstr);
        while (true) {
            while (i < end && cstr[i] == seg) i++;
            while (i < end && cstr[i] != seg) {
                s = s + cstr[i];
                i++;
            }

            res.push_back(str(s));
            s = "";
            if (i == end) {
                break;
            }
        }
        return res;
    }

    //////////////// c
    template <class T>
    str cformat(T v1) {
        return str(strf(this->c_str(), v1));
    }

    template <class T, class T2>
    str cformat(T v1, T2 v2) {
        return str(strf(this->c_str(), v1, v2));
    }

    template <class T, class T2, class T3>
    str cformat(T v1, T2 v2, T3 v3) {
        return str(strf(this->c_str(), v1, v2, v3));
    }

    friend std::ostream &operator<< (std::ostream& os, const str& s) {
        return os << s.c_str();
    }
};

class Path {
public:
    Path():_path(".") {}
    Path(const str &s):_path(s) {}

    str read_text(){

        std::ifstream t(_path.c_str());  
        if (!t.is_open()) {
            throw strf("[ERROR] IOError: Can't open file: %s", _path.c_str());
        }

        std::string s((std::istreambuf_iterator<char>(t)),  std::istreambuf_iterator<char>()); 
        return str(s);
    }

protected:
    str _path;
};


}

#endif // __PYTHON_LIKE__