C# !Conditional attribute?

Question

Does C# have a not Conditional (!Conditional, NotConditional, Conditional(!)) attribute?

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i know C#

Answer 1

#ifndef ShowDebugString
#define RemoveSDS
#endif

?

edit: For more clarification. If ShowDebugString is defined Conditional["ShowDebugString"] will be called. If ShowDebugString is not defined, Conditional["RemoveSDS"] will be called.