Operator overloads have named alternates
Operator overloads have named alternates
Microsoft docsDescription
Operator overloading allows the use of symbols to represent computations for a type. For example, a type that overloads the plus symbol + for addition would typically have an alternative member named Add. The named alternative member provides access to the same functionality as the operator. It's provided for developers who program in languages that do not support overloaded operators.
This rule examines:
- Implicit and explicit cast operators in a type by checking for methods named
To<typename>andFrom<typename>.
- The operators listed in the following table:
| C# | Visual Basic | C++ | Alternate method name | | ------------ | ------------ | ------------ | --------------------- | | + (binary) | + | + (binary) | Add | | += | += | += | Add | | & | And | & | BitwiseAnd | | &= | And= | &= | BitwiseAnd | | | | Or | | | BitwiseOr | | |= | Or= | |= | BitwiseOr | | -- | N/A | -- | Decrement | | / | / | / | Divide | | /= | /= | /= | Divide | | == | = | == | Equals | | ^ | Xor | ^ | Xor | | ^= | Xor= | ^= | Xor | | > | > | > | CompareTo or Compare | | >= | >= | >= | CompareTo or Compare | | ++ | N/A | ++ | Increment | | != | <> | != | Equals | | << | << | << | LeftShift | | <<= | <<= | <<= | LeftShift | | < | < | < | CompareTo or Compare | | <= | <= | \<= | CompareTo or Compare | | && | N/A | && | LogicalAnd | | || | N/A | || | LogicalOr | | ! | N/A | ! | LogicalNot | | % | Mod | % | Mod or Remainder | | %= | N/A | %= | Mod | | \* (binary) | \* | \* | Multiply | | \*= | N/A | \*= | Multiply | | ~ | Not | ~ | OnesComplement | | >> | >> | >> | RightShift | | >>= | N/A | >>= | RightShift | | - (binary) | - (binary) | - (binary) | Subtract | | -= | N/A | -= | Subtract | | true | IsTrue | N/A | IsTrue (Property) | | - (unary) | N/A | - | Negate | | + (unary) | N/A | + | Plus | | false | IsFalse | False | IsTrue (Property) |
\*N/A means the operator cannot be overloaded in the selected language. In C#, when a binary operator is overloaded, the corresponding assignment operator, if any, is also implicitly overloaded.
Cause
An operator overload was detected and the expected named alternative method was not found.
By default, this rule only looks at externally visible types, but this is configurable.
How to fix violations
To fix a violation of this rule, implement the alternative method for the operator. Name it using the recommended alternative name.
Example
#pragma warning disable CA2225
// The code that's violating the rule is on this line.
#pragma warning restore CA2225When to suppress
Do not suppress a warning from this rule if you're implementing a shared library. Applications can ignore a warning from this rule.