C++ elegant way to combine switch with if and variable assignment [closed] - c++

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My code looks like this
enum possible_cases; //assigned somewhere
bool decision; //assigned somewhere
//basically the default action for my possible_cases
int value = 10;
do_something(value);
switch (possible_cases)
{
case 0:
//assume covered by do_something(value)
break;
case 1:
if ( decision )
{
value = get_other_value();
do_something(value);
}
break;
case 2:
value = get_other_value(); //will return same value as in case 1
do_something(value);
break;
}
As you see
it has to run do_something() with one specific value
it might have to run do_something() with other values additionally, and the list of cases might grow, to a point, where having bools is impractical
but overall I am not happy as it is kinda redundant and I think there is a way to do it better.
I would like to stay with enum of cases
Edit:
It seems not clear where the problem is:
I see the call of the same function in 3 places, while I assume I could reduce it to 2 as I know I need to run it only 2 times at max.
It is really more the aesthetic aspect

Answer 1

The redundant part in your code is do_something(value)
So I would suggest you to separate that part of the code
enum possible_cases; //assigned somewhere
bool decision; //assigned somewhere
//basically the default action for my possible_cases
int value = 10;
switch (possible_cases)
{
case 1:
if ( decision )
value = get_other_value();
break;
case 2:
value = get_other_value(); //will return same value as in case 1
break;
}
do_something(value);

Answer 2

By adding extra layer you might do:
std::optional<int>
get_additionnal_value(Epossible_cases possible_cases, bool decision)
{
//basically the default action for my possible_cases
const int value = 10;
switch (possible_cases)
{
default:
case 0: return std::nullopt;
#if 1
case 1: return decision ? get_other_value() : value;
#else
case 1: if (!decision) return value;
[[fallthrough]];
#endif
case 2: return get_other_value(); //will return same value as in case 1
}
}
and then
do_something(10);
if (auto opt_value = get_additionnal_value(possible_cases, decision)) {
do_something(opt_value);
}