From the makers of InspIRCd.

Contents 1 Type sizes on various machines, for reference 1.1 C++ rules on type sizes 1.2 System Results 1.2.1 AMD64 Gentoo Linux 64bit, GCC Gentoo 3.4.6-r1 1.2.2 i386 FreeBSD 32bit, GCC 3.4.2 [FreeBSD]

Type sizes on various machines, for reference

This is mainly a developer resource, please contribute your system results if you have a notably different system, or a similar system with different results.

C++ rules on type sizes

1 === sizeof(char) <= sizeof(short) <= sizeof(int) <= sizeof(long)
1 <= sizeof(bool) <= sizeof(long)
sizeof(char) <= sizeof(wchar_t) <= sizeof(long)
sizeof(float) <= sizeof(double) <= sizeof(long double)

N == (char, short, int, long)
sizeof(N) === sizeof(unsigned N) === sizeof(signed N)

char >= 8 bits
short >= 16 bits
long >= 32 bits

System Results

All results generated with the following C++ program:

#include <iostream>

#define PRINT(x) (std::cout << "sizeof(" #x ") = " << sizeof(x) << std::endl)

int main()
{
        PRINT(bool);
        PRINT(char);
        PRINT(wchar_t);
        PRINT(short);
        PRINT(int);
        PRINT(float);
        PRINT(double);
        PRINT(long double);
        PRINT(long);
        PRINT(long long);
        return 0;
}

AMD64 Gentoo Linux 64bit, GCC Gentoo 3.4.6-r1

sizeof(bool) = 1
sizeof(char) = 1
sizeof(wchar_t) = 4
sizeof(short) = 2
sizeof(int) = 4
sizeof(float) = 4
sizeof(double) = 8
sizeof(long double) = 16
sizeof(long) = 8
sizeof(long long) = 8

i386 FreeBSD 32bit, GCC 3.4.2 [FreeBSD]

sizeof(bool) = 1
sizeof(char) = 1
sizeof(wchar_t) = 4
sizeof(short) = 2
sizeof(int) = 4
sizeof(float) = 4
sizeof(double) = 8
sizeof(long double) = 12
sizeof(long) = 4
sizeof(long long) = 8