throwcall.h

Go to the documentation of this file.

#ifndef __throwcall_h__
#define __throwcall_h__
 
/*
  template functions to do exceptions for standard syscalls
    Copyright (C) 2018  Juergen Hannappel
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
 
#include <system_error>
#include <sstream>
 
namespace throwcall {
    template <typename T> void conCatString(std::ostringstream& msg, const T& begin) {
        msg << begin;
    }
    template <typename T, typename ... Args> inline void conCatString(std::ostringstream& msg,
            const T& begin,
            const Args& ... args) {
        msg << begin;
        if (sizeof...(args)) {
            conCatString(msg, args...);
        }
    }
    template <typename T, typename ... Args> inline void good0(T call, const Args& ... args) {
        if (__builtin_expect(call, 0)) {
            std::ostringstream msg;
            conCatString(msg, args...);
            throw std::system_error(errno, std::system_category(), msg.str());
        }
    };
    template <typename T, typename t, typename ... Args> inline T badval(T call, t badvalue, const Args& ... args) {
        if (__builtin_expect(call == badvalue, false)) {
            std::ostringstream msg;
            conCatString(msg, args...);
            throw std::system_error(errno, std::system_category(), msg.str());
        }
        return call;
    };
}
#endif