Compiler Warning (level 4) C4221
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Compiler Warning (level 4) C4221

Error Message

nonstandard extension used : 'identifier' : cannot be initialized using address of automatic variable

With the default Microsoft extensions (/Ze), you can initialize an aggregate type (array, struct, or union) with the address of a local (automatic) variable.

Example

// C4221.c
// compile with: /W4
struct S
{
   int *i;
};

void func()
{
   int j;
   struct S s1 = { &j };   // C4221
}

int main()
{
}

Such initializations are invalid under ANSI compatibility (/Za).

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