[Dev-C++] IF

[- <ali...@nt...>]

problem with if statement:
if (letter2 !=3D 'u' || 'v' || 's' || 't' || 'a') {
  cout<<"An error has occured, check you typed in only u, v, s, t or =
a."<<endl;
  exit();
  }

Compiles ok but after checking i've realised it believes the values are =
part of an earlier enum declaration:

enum value{u,v,s,t,a};
value letter;

How do i tell the compiler i want charactors, not enum values?