How to call custom operator with Reflection
In my small project I'm using System.Reflection classes to produce executable code. I need to call the + operator of a custom type. Does anybody know how can I call customized operator of custom class using C# reflection?
Solution 1:
C# compiler converts overloaded operator to functions with name op_XXXX where XXXX is the operation. For example, operator + is compiled as op_Addition.
Here is the full list of overloadable operators and their respective method names:
┌──────────────────────────┬───────────────────────┬──────────────────────────┐
│ Operator │ Method Name │ Description │
├──────────────────────────┼───────────────────────┼──────────────────────────┤
│ operator + │ op_UnaryPlus │ Unary │
│ operator - │ op_UnaryNegation │ Unary │
│ operator ++ │ op_Increment │ │
│ operator -- │ op_Decrement │ │
│ operator ! │ op_LogicalNot │ │
│ operator + │ op_Addition │ │
│ operator - │ op_Subtraction │ │
│ operator * │ op_Multiply │ │
│ operator / │ op_Division │ │
│ operator & │ op_BitwiseAnd │ │
│ operator | │ op_BitwiseOr │ │
│ operator ^ │ op_ExclusiveOr │ │
│ operator ~ │ op_OnesComplement │ │
│ operator == │ op_Equality │ │
│ operator != │ op_Inequality │ │
│ operator < │ op_LessThan │ │
│ operator > │ op_GreaterThan │ │
│ operator <= │ op_LessThanOrEqual │ │
│ operator >= │ op_GreaterThanOrEqual │ │
│ operator << │ op_LeftShift │ │
│ operator >> │ op_RightShift │ │
│ operator % │ op_Modulus │ │
│ implicit operator <type> │ op_Implicit │ Implicit type conversion │
│ explicit operator <type> │ op_Explicit │ Explicit type conversion │
│ operator true │ op_True │ │
│ operator false │ op_False │ │
└──────────────────────────┴───────────────────────┴──────────────────────────┘
So to retrieve the operator+ method of the DateTime struct, you need to write:
MethodInfo mi = typeof(DateTime).GetMethod("op_Addition",
BindingFlags.Static | BindingFlags.Public );
Solution 2:
typeof(A).GetMethod("op_Addition").Invoke(null, instance1, instance2);