We used the following application in C++
to test the size of an enum
:
#include <iostream> using namespace std; enum SINGLE { S_ZERO = 0x0, S_FULL = 0xFFFFFFFF }; enum DOUBLE { D_ZERO = 0x0, D_FULL = 0xFFFFFFFFFFFFFFFF }; int main() { cout << "Single Zero: Size '" << sizeof(S_ZERO) << "' Value '" << S_ZERO << "'" << endl; cout << "Double Zero: Size '" << sizeof(D_ZERO) << "' Value '" << D_ZERO << "'" << endl; cout << "Single Full: Size '" << sizeof(S_FULL) << "' Value '" << S_FULL << "'" << endl; cout << "Double Full: Size '" << sizeof(D_FULL) << "' Value '" << D_FULL << "'" << endl; return 0; }
The output we got is the following:
Single Zero: Size '4' Value '0' Double Zero: Size '8' Value '0' Single Full: Size '4' Value '4294967295' Double Full: Size '8' Value '18446744073709551615'
From the result it is pretty easy to understand that the size of an enum
will grow to 64bit
when any of its values is greater than 32bit
.
For our test we used g++ (GCC) 5.3.1 20160406 (Red Hat 5.3.1-6)
on a 64bit Fedora 23.
This post is also available in: Greek
Might this be better named “get size of integer variable”