HP C/iX Reference Manual (31506-90011)

Chapter 5 71
Expressions
Cast Operators
Cast Operators
The cast operator is used to convert an expression of one type to another type.
Syntax
cast-expression :=
unary-expression
( type-name ) cast-expression
Description
An expression preceded by a parenthesized type name causes the expression to be
converted to the named type. This operation is called a cast. The cast does not alter the
type of the expression, only the type of the value. Unless the type name specifies void type,
the type name must specify a scalar type, and the operand must have scalar type.
The result of a cast operation is not an lvalue.
Conversions involving pointers (other than assignment to or from a "pointer to void" or
assignment of a null pointer constant to a pointer) require casts.
A pointer can be cast to an integral type and back again provided the integral type is at
least as wide as an int.
A pointer to any object can safely be converted to a pointer to char or a pointer to void,
and back again. If converted to a pointer to char, it will point to the first (lowest address)
byte of the original object. For example, a pointer to an integer converted to a character
pointer points to the most significant byte of the integer.
A pointer to a function of one type can safely be converted to a pointer to a function of
another type, and back again.