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c++mingwmingw-w64

std::max_align_t unable to print its value


I am trying to print the value of std::max_align_t in MinGW64. Below is my code:

#include <stdio.h>
#include <cstddef>

int main()
{
    printf("max allign: %d\n", alignof(std::max_align_t));
}

When I compile I get the below error:

/c/tools/mingw64/bin/c++.exe test23.cpp -Wall -ftrack-macro-expansion=0 -Werror -std=gnu++14 -Og -g3 -o test23.exe -Wl,--out-implib,test23.a -Wl,--major-image-version,0,--minor-image-version,0  -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32
test23.cpp: In function 'int main()':
test23.cpp:6:57: error: format '%d' expects argument of type 'int', but argument 2 has type 'long long unsigned int' [-Werror=format=]
     printf("max allign: %d\n", alignof(std::max_align_t));
                                                         ^
cc1plus.exe: all warnings being treated as errors

So I changed to below code:

#include <stdio.h>
#include <cstddef>

int main()
{
    printf("max allign: %llu\n", alignof(std::max_align_t));
}

But still I receive below error during compilation:

/c/tools/mingw64/bin/c++.exe test23.cpp -Wall -ftrack-macro-expansion=0 -Werror -std=gnu++14 -Og -g3 -o test23.exe -Wl,--out-implib,test23.a -Wl,--major-image-version,0,--minor-image-version,0  -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32
test23.cpp: In function 'int main()':
test23.cpp:6:59: error: unknown conversion type character 'l' in format [-Werror=format=]
     printf("max allign: %llu\n", alignof(std::max_align_t));
                                                           ^
test23.cpp:6:59: error: too many arguments for format [-Werror=format-extra-args]
cc1plus.exe: all warnings being treated as errors

If I remove 'l' from the printf I get back to same error? How can I resolve the issue.


Solution

  • Since you are using C++ you can go with this

    #include <iostream>
    #include <cstddef>
    
    int main()
    {
        std::cout << alignof(std::max_align_t) << '\n';
    }