compiler-warning-level-3-c4240.md

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Learn more about: Compiler Warning (level 3) C4240	Compiler Warning (level 3) C4240	11/04/2016	C4240	C4240	a2657cdb-18e1-493f-882b-4e10c0bca71d

Compiler Warning (level 3) C4240

nonstandard extension used : access to 'classname' now defined to be 'access specifier', previously it was defined to be 'access specifier'

Under ANSI compatibility (/Za), you cannot change the access to a nested class. Under the default Microsoft extensions (/Ze), you can, with this warning.

Example

// C4240.cpp
// compile with: /W3
class X
{
private:
   class N;
public:
   class N
   {   // C4240
   };
};

int main()
{
}