6.6 Overloading of Operators
Name Resolution Rules
Each use of a unary or binary operator is equivalent
to a
function_call
with
function_prefix
being the corresponding
operator_symbol,
and with (respectively) one or two positional actual parameters being
the operand(s) of the operator (in order).
Legality Rules
The
subprogram_specification
of a unary or binary operator shall have one or two parameters, respectively.
The parameters shall be of mode
in. A generic function instantiation
whose
designator
is an
operator_symbol
is only allowed if the specification of the generic function has the
corresponding number of parameters, and they are all of mode
in.
An explicit declaration of "/=" shall not
have a result type of the predefined type Boolean.
Static Semantics
An explicit declaration of "=" whose result
type is Boolean implicitly declares an operator "/=" that gives
the complementary result.
8 The operators "+" and "–"
are both unary and binary operators, and hence may be overloaded with
both one- and two-parameter functions.
Examples
Examples of user-defined
operators:
function "+" (Left, Right : Matrix) return Matrix;
function "+" (Left, Right : Vector) return Vector;
-- assuming that A, B, and C are of the type Vector
-- the following two statements are equivalent:
A := B + C;
A := "+"(B, C);
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