Navigating C++ and Object-Oriented Design

2.1. Data Representation and Built-in Types

The C++ compiler manipulates built-in types in your programs. Data type representation is machine specific in C++, but Table 2.1 lists typical sizes.

Table 2.1. Typical built-in type sizes in bits

Built-in Type	16-Bit Word Size	32-Bit Word Size	64-Bit Word Size
char (signed)	8	8	8
wchar_t (signed)	16	16	16
int (signed)	16	32	32
bool	16	32	32
short (signed)	16	16	16
long (signed)	32	32	64
float (signed)	32	32	32
double (signed)	64	64	64
unsigned char	8	8	8
unsigned int	16	32	32
unsigned short	16	16	16
unsigned long	32	32	64
long double (signed)	64	128	128

Integer formats (one's complement or two's complement) and extended precision formats are machine dependent and have different representations. Built-in ...