MSVC const correctness : spurious C4090 warning

Question

MSVC emits warning C4090 about const correctness while both GCC and Clang accept it: Compiler Explorer .

void dummy(void)
{
    int i[42];
    int *pi[42];
    int const *pci[42];
    memset(i, 0, sizeof i);
    memset(pi, 0, sizeof pi);
    memset(pci, 0, sizeof pci); // warning C4090: 'function': different 'const' qualifiers
}

It seems MSVC treats pci as constant when it's not.

This bug is apparently awfully old . Any idea how to fix this without turning C4090 off?

Answer 1

You can disable this warning right before the line which invokes it and restore it back afterwards https://godbolt.org/z/W-XR-Q :

#include <string.h>

void dummy(void)
{
    int i[42];
    int *pi[42];
    const int *pci[42];

    memset(i, 0, sizeof i);
    memset(pi, 0, sizeof pi);

#pragma warning( push )
#pragma warning( disable : 4090)
    memset(pci, 0, sizeof pci); // NO warning C4090
#pragma warning( pop ) 
}