Why doesn't this reinterpret_cast compile?

Question

I understand that reinterpret_cast is dangerous, I\'m just doing this to test it. I have the following code:

int x = 0;
double y = reinterpret_c         


        

Answer 1

Use a union. It is the least error-prone way to memory map between an integer and a floating point type. Reinterpreting a pointer will cause aliasing warnings.

#include 
#include 

int main(int argc, char *argv[])
{
    union { uint32_t i; float f; } v;  // avoid aliasing rules trouble
    v.i = 42;
    printf("int 42 is float %f\n", v.f);
    v.f = 42.0;
    printf("float 42 is int 0x%08x\n", v.i);
}