The ANSI C standard suggests several environmental limits on the use of the C language. These limits are an effort to define minimal standards for a conforming implementation of a C compiler. For example, the number of significant characters in an identifier is implementation-defined, with a minimum set required by the ANSI C standard.
The standard also includes several numerical limits that restrict the characteristics of integral and floating-point types. For the most part, these limits will not affect your use of the C language or compiler. However, for unusually large or unusually constructed programs, certain limits can be reached. The ANSI standard contains a list of minimum limits, and your platform-specific DEC C documentation contains the actual limits used in DEC C.
As intended by the ANSI C standard, the DEC C implementation avoids imposing many of the translation limits, allowing applications more flexibility. The DEC C limits are:
Numerical limits define the sizes and characteristics of
integral and floating-point types. Numerical limits are described in
the limits.h and float.h header files. The
limits are:
char is represented in
8 bits.
wchar_t is represented
in 32 bits.
char type is the same as for the signed
char type. A compiler command-line option changes this
equivalence to unsigned char .
int and signed
int types are the same as for the long int
type.
unsigned int type are the
same as for the unsigned long int type.
long int
and unsigned long int types are 64 bits, while
int and unsigned int are 32 bits.
long double type is the same as for the
double type.
Characters from the executable character set are output to the active position on the screen or in a file. The active position is defined by the ANSI C standard as the spot where the next output character will appear. After a character is output, the active position advances to the next position on the current line (to the left or right).
The DEC C compiler moves the active position from left to right across an output line.