compiler-warning-level-4-c4764.md

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Learn more about: Compiler Warning (level 4) C4764	Compiler Warning (level 4) C4764	11/04/2016	C4764	C4764	7bd4296f-966b-484c-bf73-8dbc8e85b4a9

Compiler Warning (level 4) C4764

Cannot align catch objects to greater than 16 bytes

An alignment greater than 16 was specified, but on some platforms, if the function throws an exception, the stack will force an alignment of not greater than 16.

Example

The following sample generates C4764:

// C4764.cpp
// compile with: /W4 /EHsc
// processor: x64 IPF
#include <stdio.h>

class A
{
public:
    int x;
};

typedef __declspec(align(32)) A ALIGNEDA;

int main()
{
    ALIGNEDA a;
    try
    {
        a.x = 15;
        throw a;
    }
    catch (ALIGNEDA b) // can't align b to > 16 bytes
    {
        printf_s("%d\n", b.x);
    }
}   // C4764