2. Operators¶
2.1. Precedence¶
| Precedence | Operator | Description | Associativity |
|---|---|---|---|
| 1 (highest) | :: |
Scope resolution | N/A |
| 2 | ++ |
Postfix increment | Left-to-right |
-- |
Postfix decrement | ||
() |
Function call | ||
[] |
Array/Slice subscripting | ||
. |
Struct member selection | ||
expect!type |
Safe cast (explicit implicit cast) | ||
cast!type |
Static cast | ||
const_cast!type |
CV removal cast | ||
reinterpret_cast!type |
|||
@ |
Pointer dereference | ||
& |
Address-of | ||
| 3 | ++ |
Prefix increment | Right-to-left |
-- |
Prefix decrement | ||
+ |
Unary plus | ||
- |
Unary minus | ||
~ |
Bitwise NOT (One’s complement) | ||
! |
Logical NOT | ||
| 4 | Reserved [1] | ||
| 5 | * |
Multiplication | Left-to-right |
/ |
Division | ||
% |
Modulo (remainder) | ||
& |
Bitwise AND [2] | ||
| 6 | + |
Addition | Left-to-right |
- |
Subtraction | ||
| |
Bitwise OR [2] | ||
^ |
Bitwise XOR [2] | ||
| 7 | << [3] |
Left shift | Left-to-right |
>> [3] |
Right shift | ||
| 8 | < |
Less than | Left-to-right |
<= |
Less than or equals | ||
> |
Greater than | ||
>= |
Greater than or equals | ||
| 9 | == |
Equals | Left-to-right |
!= |
Not equals | ||
| 10 | && |
Logical AND | Left-to-right |
| 11 | || |
Logical OR | Left-to-right |
| 12 | = |
Assignement | Right-to-left |
+= |
Additive assignment | ||
-= |
Subtractive assignment | ||
*= |
Multiplicative assignment | ||
/= |
Division assignment | ||
%= |
Modulo assignment | ||
<<= |
Left shift assignment | ||
>>= |
Right shift assignment | ||
&= |
Bitwise AND assignment | ||
^= |
Bitwise XOS assignment | ||
|= |
Bitwise OR assignment | ||
2.2. Remarks¶
- Practical has no conditional operator (
?:). Instead,ifcan be used as an expression to the same effect. - Practical has no comma operator (
,). Aside from being a horrible abomination, a compound expression can serve the precise same purpose. - Compared to C/C++, the priority of the bitwise operations (
&,|and^) has changed. They now have a higher precedence than their logical counterparts, and the same precedence as their respective algebraic operations. While this might introduce some confusion, it is believed that 99% of expressions involving both bitwise operations and logical ones in C/C++ either already have parenthesis around the logical ones or are bugs. As such, the (negative) impact is expected to be minimal. - The pointer-to-method/member dereference operator does not, yet, appear in the table above. It has precedence level 4 reserved for it (same as C++), but that precedence, in all likelihood, represents a bug in C++. It is very likely that the final precedence for this operator will be 2. This seems a safer change than the bitwise operators change, as getting this one wrong is almost guaranteed to result in a compilation error.
- The bitwise shift operators (
<<and>>) are only legal for unsigned integers (unless overloaded, of course). Trying to use them on a signed integer will result in a promotion to integer (if VRP allows it) or a compilation error.
Footnotes
| [1] | Precedence level 4 is reserved for the pointer to member/method operator. If implemented, it will likely not remain at level 4 (as it is in C++), but rather at level 2, where it belongs. |
| [2] | (1, 2, 3) This precedence is higher than in C++ |
| [3] | (1, 2) Defined by default only for the unsigned integer types |