being dumb again

[ansgar.snow]

I stumble on some simple prime generator implementation in basic C, it was supposed to be something like function returning array of size_t values:

size_t *  primeGen(size_t _MAX_)
{
    size_t primes[_MAX_];
    int PrimeIndex = 2;


    primes[0] = 2; primes[1] = 3;


    for (size_t p = primes[1] ; p < _MAX_  ; p = p + 2)
    {
        int isPrime = 1;
        
        for (size_t j = 1 ; j < primes[PrimeIndex] / 2 ; ++j )
        {


            if (p % primes[j] == 0) isPrime = 0; 
            
        }
        
        if (isPrime) 
            {
                primes[PrimeIndex] = p ; PrimeIndex++ ;
            }


    }return primes[PrimeIndex];
}

error: invalid conversion from ‘size_t’ {aka ‘long unsigned int’} to ‘size_t*’ {aka ‘long unsigned int*’} [-fpermissive]

Tried to force casting size_t* on that return but it also doesn't work. Idk but I just keep forgetting everything about C, feels easier to do things in Cpp with vectors and strings modules etc.

[Salem]

> return primes[PrimeIndex];
The basic problem is you can't return an array.

This would fix the syntax error.
return primes;

But the problem is, your array goes out of scope by the time the caller gets to look at the data.

void primeGen(size_t _MAX_, size_t primes[_MAX_])

You make the caller pass in a suitable sized array for you to fill in.