I don't know what the problem. Can't detect the error.

[training91st]

Help me solve this error please

#include <iostream>
using namespace std;
enum days {mon=1, tue, wed, thu, fri, sat, sun};

void main()
{
     
     enum days day_count;
     
     cout<<"Simple day count\n";
     cout<<"       using enum\n";
     
     for(day_count=mon; day_count<=sun; day_count++)
     cout<<" "<<day_count<<"\n";
     
}

[training91st]

I'm using window 8

[chipp]

i don't think that enumeration can be use for increment operations... maybe you better use switch

[training91st]

chipp i need to use enumeration. you got any other way to solve it?

[JLBorges]

Either

for( day_count=mon; day_count<=sun; /*day_count++*/ day_count = days(day_count+1) ) 
{ /* ... */ }

Or overload the increment operator:

#include <iostream>

enum day_t { mon=1, tue, wed, thu, fri, sat, sun, invalid } ;

day_t& operator++( day_t& d ) { return d = day_t( d + 1 ) ; }

// EDIT: corrected to fix the error pointed out by chipp
day_t operator++( day_t& d, int ) { auto old_value = d ; ++d ; return old_value ; }

int main()
{
     for( day_t d = mon ; d != invalid ; ++d ) std::cout << d << ' ' ;
     std::cout << '\n' ;
}

[training91st]

can you give me more details JLBorges?

for( day_count=mon; day_count<=sun; /*day_count++*/ day_count = days(day_count+1) ) 
{ /* ... */ }

[vlad from moscow]

day_t & operator ++( day_t &d ) 
{
   if ( d ==  sun ) return d = mon;
   return d = static_cast<day_t>( d + 1 ) ; 
}

[training91st]

can't. anyone help please? easy way

[vlad from moscow]

I do not understand what help you need. All was already shown. What is the problem? You may simplify your ptogram the following way

#include <iostream>

using namespace std;
enum days {mon=1, tue, wed, thu, fri, sat, sun};

int main()
{
     cout<<"Simple day count\n";
     cout<<"       using enum\n";
     
     for ( int day_count = mon;  day_count <= sun; day_count++ )
     {
          cout << " " << day_count << "\n";
     }
}

[JLBorges]

> can you give me more details JLBorges?
> for( day_count=mon; day_count<=sun; /*day_count++*/ day_count = days(day_count+1) )
>> easy way

There isn't anything easier than:

for( day_count=mon; day_count<=sun; day_count = days(day_count+1) ) 
{ /* ... */ }

1. day_count can be implicitly converted to an int
2. day_count+1 yields an integer with a value one higher than the integer value of day_count
3. days(day_count+1) casts that integer to an object of type days
4. which is assigned to day_count

[training91st]

thanks i will try. thanks so much JLBorges

[training91st]

JLBorges, what do you mean by this?
i'm not very understand

for( day_count=mon; day_count<=sun; /*day_count++*/ day_count = days(day_count+1) ) 
{ /* ... */ }

[vlad from moscow]

Expression day_count+1 is implicitly converted to an integral type. However an integral expression can not be implicitly converted to an enumeration type. You shall explicitly specify the type of enumeration to which you want to convert an integral expression. And this record

days(day_count+1)

means that expression

day_count+1

must be converted to the enumeration type enum days.

[chipp]

day_t& operator++( day_t& d ) { return d = day_t( d + 1 ) ; }

day_t operator++( day_t& d, int ) { return ++d ; }

actually i asked this code in another group, they said that the postfix operator overloading is wrong, it should be:

day_t operator++( day_t& d, int ) {
	day_t dummy = d;
	++d;
	return dummy;
}

it wasn't my actual question, but this one is right too... so i just want to verify your code...

and, can someone give me links for operator++ overloading?

[JLBorges]

Yes, this is wrong:
day_t operator++( day_t& d, int ) { return ++d ; }

Should be as in your example; make a copy before the increment and return the copy.

Thanks for pointing it out, I've corrected it now.

operator++ overloading:
http://www.parashift.com/c++-faq-lite/increment-pre-post-overloading.html

[chipp]

you're welcome, thx for the link... checking it now...