Compiler Warning (level 4) C4214

nonstandard extension used : bit field types other than int

With the default Microsoft extensions (/Ze), bitfield structure members can be of any integer type.

Example

// C4214.c
// compile with: /W4
struct bitfields
{
   unsigned short j:4;  // C4214
};

int main()
{
}

Such bit fields are invalid under ANSI compatibility (/Za).