Method Names for Operator Methods in C#

Question

Does anyone have a exhaustive list of the names that C#/CLR gives to operators? (Maybe my lack of sleep is kicking in, but I can't seem to find it on Google) E.g. op_Addition, op_Subtraction. Furthermore is there any chance that these would be different in other cultures?

I am trying to create a class that can add/subtract etc. two objects and I have done all the primitives - I just need to do the 'rest'.

Many thanks.

This is covered more fully in http://stackoverflow.com/questions/3016429/reflection-and-operator-overloads-in-c-sharp — John Pursey, Aug 22 '12 at 18:11

IS4 · Answer 1 · 2017-01-02T02:29:24.543

8

Based on the Expression class:

== op_Equality
!= op_Inequality
>  op_GreaterThan
<  op_LessThan
>= op_GreaterThanOrEqual
<= op_LessThanOrEqual
&  op_BitwiseAnd
|  op_BitwiseOr
+  op_Addition
-  op_Subtraction
/  op_Division
%  op_Modulus
*  op_Multiply
<< op_LeftShift
>> op_RightShift
^  op_ExclusiveOr
-  op_UnaryNegation
+  op_UnaryPlus
!  op_LogicalNot
~  op_OnesComplement
   op_False
   op_True
++ op_Increment
-- op_Decrement

edited Jan 02 '17 at 02:29

answered Apr 07 '15 at 15:15

IS4

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Is it possible to use these with `nameof()`? – Aaron Franke Sep 16 '21 at 20:49
@AaronFranke No, operators cannot be referenced directly. – IS4 Sep 17 '21 at 08:36

score 6 · Accepted Answer · edited Feb 15 '19 at 01:32

6

Here is the full list of C# overloadable operators

You can find a list of the operator Metadata/Generated MSIL names under Framework Design Guidelines -> Operator Overloads.

There is a different F# operator overload list.

Finally, refer to ECMA-335 Common Language Infrastructure (CLI) I.10.3 Operator overloading, where the operators for C++/CLI are listed.

edited Feb 15 '19 at 01:32

Theraot

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answered Mar 16 '09 at 05:44

Reed Copsey

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I know, but I need the actual method names in the final assembly, like op_Addition... Maybe I will go implement them all and reflect. – Jonathan C Dickinson Mar 16 '09 at 05:56
Jonathan, I believe the new link above has what you want. – Reed Copsey Mar 16 '09 at 06:05
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Dang! The link is no longer active. I wonder where I can get this list now? – John Alexiou Dec 19 '12 at 16:55

score 4 · Answer 3 · edited May 23 '17 at 12:08

The accepted answer is good because it links to a list of overloadable operators, but it doesn't strictly answer the question because it doesn't provide the names of the operators when they are compiled.

The runner up answer includes that, but it is an incomplete list and not well organized. For completeness' sake, I made my own list, including a few operators that you might expect to be overloadable but that aren't. The list is in order of operator precedence, from highest (tightest) priority to lowest.

Outside of Order of Operations (used when necessary to coerce types)
   op_Implicit
   op_True
   op_False

Unary (only one operator)
++ op_Increment (Includes preincrement and postincrement)
-- op_Decrement (Includes predecrement and postdecrement)
-  op_UnaryNegation
+  op_UnaryPlus
!  op_LogicalNot
~  op_OnesComplement
   op_Explicit
await (Not overloadable)

Multiplicative
/  op_Division
%  op_Modulus
*  op_Multiply

Additive
+  op_Addition
-  op_Subtraction

Shift
<< op_LeftShift
>> op_RightShift

Relational
>  op_GreaterThan
<  op_LessThan
>= op_GreaterThanOrEqual
<= op_LessThanOrEqual
as (Not overloadable)
is (Not overloadable)

Equality
== op_Equality
!= op_Inequality

And
&  op_BitwiseAnd

Exclusive Or
^  op_ExclusiveOr

Inclusive Or
|  op_BitwiseOr

Conditional And
&& (Not overloadable - use "implicit operator bool" or "operator true")

Contional Or
|| (Not overloadable - use "implicit operator bool" or "operator true")

Null-Coalescing Operator
?? (Not overloadable)

Ternary
?: (Not overloadable - use "implicit operator bool" or "operator true")

Assignment
=  (Not overloadable - for combined operator and assignment (such as +=), just use the operator (+))

Note: The C# compiler prefers implicit operator bool instead of the True and False operators, if both are defined.

According to a referenced StackOverflow question, the following method names are also emitted/understood by the C# compiler, but

I have run tests in Visual Studio 2015 and C#6.0 attempting to get these to work, and
The C#5.0 spec lists the "complete set of unary [and binary] operator function names" (Appendix A, page 469) and these appear nowhere therein.

Unary
&   op_AddressOf
*   op_PointerDereference

Binary
.   op_MemberSelection
->  op_PointerToMemberSelection

    op_SignedRightShift
    op_UnsignedRightShift

=   op_Assign
*=  op_MultiplicationAssignment
/=  op_DivisionAssignment
%=  op_ModulusAssignment
-=  op_SubtractionAssignment
+=  op_AdditionAssignment
<<= op_LeftShiftAssignment
>>= op_RightShiftAssignment
|=  op_ExclusiveOrAssignment
&=  op_BitwiseAndAssignment
|=  op_BitwiseOrAssignment

    op_UnsignedRightShiftAssignment
    op_SignedRightShiftAssignment

,   op_Comma

That's really interesting, I guess these operator names are understood because of C++/CLI. I have checked the IL of a mixed mode assembly recently, and these names are used for classes compiled to managed code. — IS4, Jan 12 '18 at 14:41

score 0 · Answer 4 · answered Feb 17 '14 at 12:51

0

This website gives the list of names for C# operators, displaying the operator, Action (name), Example & Result: C# Operator List

answered Feb 17 '14 at 12:51

AaronParkes

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Method Names for Operator Methods in C#

4 Answers4

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