c# - Generic extension method, operators -

i make method "transforms" 1 space another. quite simple thing template in c++ in c# i'm not sure interface/type or how need use "where" clause in order compiler understand want. c++ function looked this:

template<class t> t transform(t s, t s1, t s2, t d1, t d2) {         t result = (s - s1) / (s2 - s1) * (d2 - d1) + d1;                 return result; }    

and first stab @ generic c# version (in extension methods), looks this:

public static t transform<t>(t s, t s1, t s2, t d1, t d2) {         t result = (s - s1) / (s2 - s1) * (d2 - d1) + d1;                 return result; } 

alas c# me more specific types, i.e.

"error cs0019: operator '-' cannot applied operands of type 't' , 't'".

what c# want me do?

you cannot directly tell compiler via constraint t implements operator. can tell compiler t implements class. if class overloads operator, can use it.

for example, class defines '-' operator

public class stuff {     public stuff(int number) {         number = number;     }      public int number { get; set; }      public static stuff operator -(stuff a, stuff b) {         return new stuff(a.number - b.number);     }      //define other operators in same way... } 

then, in method, can this:

public static t transform<t>(t s, t s1, t s2, t d1, t d2)     t : stuff {     stuff result = (s - s1) / (s2 - s1) * (d2 - d1) + d1;     return (t)result; } 

alternatively, can use dynamic, throw exception if operator not exist.