为什么我会在 VS2019 和 /std:c++latest

如何解决为什么我会在 VS2019 和 /std:c++latest

编译小测试程序

#include <string>
#pragma pack(show)
template<typename TTTTT,int OOOOO>
void xxxxxx(TTTTT(&)[OOOOO]){}
#pragma pack(show)
#include <locale>
int main() {}

使用最新的 VS2019 V16.9.0 for x64 我收到一堆关于对齐更改的 C4103 警告：

1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.28.29910\include\system_error(18,1): warning C4103: alignment changed after including header,may be due to missing #pragma pack(pop)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.28.29910\include\xiosbase(12,may be due to missing #pragma pack(pop)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.28.29910\include\streambuf(11,may be due to missing #pragma pack(pop)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.28.29910\include\xlocbuf(11,may be due to missing #pragma pack(pop)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.28.29910\include\locale(11,may be due to missing #pragma pack(pop)

Here's a godbolt。

我找不到原因。 对齐似乎被模板定义改变了，但我不明白为什么，也不明白为什么 #pragma pack(show) 在输出两个警告行之后。