How can I manually set the bit value of a float that equates to NaN?

Question

I\'m trying to run some tests with conversions and castings of floats to other types and I want to set my float variable to different values of nan.

\"a bit-wise exa

Answer 1

Use memcpy:

int32_t i = 0x7FC00000;
float f;
memcpy(&f, &i, sizeof(f));

You could also assert that sizeof(f) == sizeof(i), but if you know that floats are IEEE then presumably you also know what size the basic types are.