Implements non-standard C++ friend declaration behavior that allows friend declarations to be visible in the enclosing scope.
#pragma old_friend_lookup on | off | reset
This example shows friend declarations that are invalid without #pragma old_friend_lookup.
class C2; void f2(); struct S { friend class C1; friend class C2; friend void f1(); friend void f2(); }; C1 *cp1; // error, C1 is not visible without namespace declaration C2 *cp2; // OK int main() { f1(); // error, f1() is not visible without namespace declaration f2(); // OK }