Expression type and precision

Primary (single-operator) expression type and calculation precision depends on the operand that has higher precision class. There are 4 precision classes:

1. int (int, word, byte). In expressions, word and byte are implicitly converted to int.

2. unsigned int (pointers (including lpstr and interface pointers), unsigned int constants).

3. long (long).

4. double (double, OLE types).

The following are the exceptions:

• If operator is logical or comparison, expression type is int (result 0 or 1).
• Else, if both operands are lpstr or pointer, and operator is -, expression type is int (difference between two pointers).
• Else, if operand1 is lpstr or pointer, and operand2 is int (int, byte or word) or unsigned int, expression type is type of operand1.
• Before calculating a bitwise operator, operands are converted to unsigned int or unsigned long.
• Before calculating the % operator (integer remainder), double operands are converted to int or long.

Type of more complex expression can be found by splitting it to primary expressions.