What does the C standard state the size of int long type to be

Question

I'm seeking for specific information on the sizes of basic C++ types. 

I understand that it is determined by the architecture (16 bits, 32 bits, or 64 bits) and the compiler.

But are there any C++ standards?

On a 32-bit architecture, I'm using Visual Studio 2008. 

This is what I get:

char  : 1 byte
short : 2 bytes
int   : 4 bytes
long  : 4 bytes
float : 4 bytes
double: 8 bytes

I looked for solid information on the sizes of char, short, int, long, double, float (and additional kinds I didn't think of) under different architectures and compilers, but had little luck.

Answer 1

The 'de facto' standard for 32-bit platforms is ILP32, which means that int, long, and pointer are all 32-bit numbers.

The basic Unix 'de facto' standard for 64-bit computers is LP64 — long and pointer are both 64-bit (but int is 32-bit).

LLP64 is the Windows 64-bit standard – long long and pointer are both 64-bit (but long and int are both 32-bit).

Some Unix systems once utilised an ILP64 structure.

The C standard (ISO/IEC 9899:1999) does not mandate any of these de facto standards, although they are all authorised under it.

And, despite the test in the Perl configure script, sizeof(char) is defined as 1.

It should be noted that on some devices (Crays), CHAR BIT was substantially greater than 8.

Because char and int were both 32-bit values, sizeof(int) was likewise 1.