strings.h

 
#ifndef THEORETICA_IO_STRINGS_H
#define THEORETICA_IO_STRINGS_H
 
#include <string>
 
 
namespace theoretica {
namespace io {
 
 
    inline bool is_number(const std::string& str) {
 
        if (str.empty())
            return false;
 
        const std::string allowed = "1234567890.,Ee+-Nnaif";
 
        for (char c : str)
            if (allowed.find(c) == std::string::npos)
                return false;
 
        return true;
    }
 
 
    inline std::string trim(const std::string& str) {
        
        size_t start = 0;
        while (start < str.length() && std::isspace(str[start]))
            ++start;
        
        size_t end = str.length();
        while (end > start && std::isspace(str[end - 1]))
            --end;
        
        return str.substr(start, end - start);
    }
 
 
    inline std::string unquote(const std::string& str) {
 
        if (str.length() >= 2 && str.front() == '"' && str.back() == '"')
            return str.substr(1, str.length() - 2);
 
        return str;
    }
 
}}
 
 
#endif