Expression Value is Constant (EVC)

Description:

EVC detects expressions that always evaluate to the same value, whatever the operand values may be. EVC detects expressions where a constant value is constructed from compile-time constant expressions and does not produce a warning message in such cases.

Incorrect:

procedure putChar(c:char; isLetter:boolean; isDigit:boolean);
var isLetterOrDigit:boolean;
begin
    if isDigit then 
        isLetterOrDigit := isLetter or isDigit;
    ...
end;