C using switch-case return value as a condition for if statement-CodePudding

May one write something like this in c :

// ...
if(value <= switch(secValue){
   case First:
      return 1;
   case Second:
      return 2;
   return -1;
}){
   //... do some logic ...
} // end if

Thanks

CodePudding user response：

Exactly this, no. But you could get close with a lambda expression.

Example:

#include <iostream>
int main() 
{
    // dummy types and values needed for demo
    enum test_enum 
    {
        First, Second
    } secValue = First;
    int value = 1;
    
    if (value <= [secValue]() 
    //            ^ Capture secValue in lambda expression
            {
                switch (secValue) 
                {
                    case First:
                        return 1;
                    case Second:
                        return 2;
                    default: // needed default case. Can't just have a stray return 
                             // in a switch
                        return -1;
                }
            }()) 
    //       ^ immediately invoke lambda    
    {
        std::cout << "Huzah!";
    } 
}

CodePudding user response：

Not with a `switch’, but with the ternary operator:

if (value <= (secValue == First ? 1
    : secValue == Second ? 2
    : -1)) {
    // . . .
}

But you really should put the right-hand side in a function so that the code is more readable.