Question
Weird behaviour with 'if constexpr' and templates in MSVC
The code below behaves incorrectly.
When f<0> or f<5> is called, it prints as if k = true, but the if statement behaves as if k = false. When f<1> is called, it does the opposite.
The bug does not appear without templates, constexpr, or the negator(!). It can be removed by having a separate variable (see below). I'm assuming this has something to do with how MSVC deals with templates?
#include <stdio.h>
const bool k = false;
template<int n>
void f()
{
printf("%d %d\n", k, n); //prints 1 0 or 1 5 when calling f<0> or f<5>, respectively
//kop = !k
if constexpr(!k)//if constexpr(kop) works fine
{
//doesn't enter the conditional when calling f<1>
int f = 9;
printf("%d %d\n", f, n);
}
}
int main()
{
f<0>();
f<1>();
f<1>();
f<5>();
}
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