‘numeric_limits’ was not declared in this scope, no matching function for call to ‘max()’

Question

I compiled this code at home on my mac w/ xcode and there was no provblem. I compile it at school with g++ on linux and I get these errors:

numeric_limits’ is not a member of std

expected primary-expression before ‘>’ token

no matching function for call to ‘max()’

    #include <iostream>
    #include <cstdlib>

    using namespace std;

    int GetIntegerInput(int lower, int upper)
    {
        int integer = -1;
        do
        {    
            cin >> integer;
            cin.clear();
            cin.ignore(std::numeric_limits<streamsize>::max(), '\n');  //errors here
        } while (integer < lower || integer > upper);
    
        return integer;    
    } 

I'm guessing maybe I have to include an extra header. If I take away the std:: it just gives me a similar error:

numeric_limits was not declared in this scope

Answer 1

You need to include the header file <limits>, which is where std::numeric_limits is defined. Your Mac compiler was helping you out by automatically including that header file; however, you should not rely on that behavior and explicitly include any header files you need.