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28 changes: 18 additions & 10 deletions docs/error-messages/compiler-warnings/compiler-warning-level-4-c4324.md
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Original file line number Diff line number Diff line change
@@ -1,27 +1,35 @@
---
description: "Learn more about: Compiler Warning (level 4) C4324"
title: "Compiler Warning (level 4) C4324"
ms.date: "11/04/2016"
description: "Learn more about: Compiler Warning (level 4) C4324"
ms.date: 07/22/2025
f1_keywords: ["C4324"]
helpviewer_keywords: ["C4324"]
---
# Compiler Warning (level 4) C4324

> '*structname*': structure was padded due to alignment specifier
> '*type*': structure was padded due to alignment specifier

## Remarks

Padding was added at the end of a structure because you specified an alignment specifier, such as [__declspec(align)](../../cpp/align-cpp.md).
Padding was added at the end of a class/struct/union because you specified an alignment specifier, such as [`alignas`](../../cpp/alignas-specifier.md) or [`__declspec(align)`](../../cpp/align-cpp.md).

For example, the following code generates C4324:
## Example

For example, `S1` and `S2` generates C4324 because padding is added when the specified alignment is greater than the default alignment of `1` and `4` respectively:

```cpp
// C4324.cpp
// compile with: /W4
struct __declspec(align(32)) A
// compile with: /W4 /c

struct alignas(4) S1 {}; // C4324

struct alignas(8) S2
{
char a;
int i;
}; // C4324

int main()
struct alignas(4) S3
{
}
int i;
}; // OK
```
2 changes: 1 addition & 1 deletion docs/error-messages/compiler-warnings/compiler-warnings-c4200-through-c4399.md
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Expand Up @@ -113,7 +113,7 @@ The articles in this section describe Microsoft C/C++ compiler warning messages
|Compiler warning (level 1) C4321|automatically generating an IID for interface '*interface*'|
|Compiler warning (level 1) C4322|automatically generating a CLSID for class '*class*'|
|Compiler warning (level 1) C4323|re-using registered CLSID for class '*class*'|
|[Compiler warning (level 4) C4324](compiler-warning-level-4-c4324.md)|'*structname*': structure was padded due to alignment specifier|
|[Compiler warning (level 4) C4324](compiler-warning-level-4-c4324.md)|'*type*': structure was padded due to alignment specifier|
|[Compiler warning (level 1) C4325](compiler-warning-level-1-c4325.md)|attributes for standard section '*section*' ignored|
|[Compiler warning (level 1) C4326](compiler-warning-level-1-c4326.md)|return type of '*function*' should be '*type1*' instead of '*type2*'|
|Compiler warning C4327|'*assignment*': indirection alignment of LHS ('*alignment1*') is greater than RHS ('*alignment2*')|
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